V/JI1265

THE FFF~'IS OF LOGGING AND TREATMENT ON THE MIXED DIPTEROOjW FORmTS

OF SOUTH EAST ASIA

by

D.I. Nicholson FAO Consultant

Department of Forestry, Australia

FOOD IJiD J.OfuCUL'iURE ORO.UIIZA.TIOH OP 'mE tmlnl) HlTIOliS

Rome, 1979

FO: JIISC /79/8 Jlaroh 1979 DIW'l'

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FOREWORD

The Mixed Dipterocarp Forest is the main vegetation type in insular South East Asia and constitutes the moet productive forest type, which has been heavily exploited since 1960.

Removals in the four countries studied, estimated to be about 17 million m3 in 1966• increased two and threefold in 1970 and 1975 respective~.

The intense exploitation of the Xi xed Dipteroearp Forest hao not been compensated by appropriate logging and management practices, which would ensure sustaitted productivity. This is of deep ooncern not only to forestero and ecologists ·out aleo to induetrialists, who fear that the resources will be exhausted in the next one or two decades with l~rmful consequences on the environment and econ~ of the region.

In an attempt to search for a solution to the problems of the mana&ement of the Mixed Dipterocarp Forests, FAO secured the services of Mr. D.I. Nicholson (Forest Research Officer, Atherton, Queensland, Australia) known for his experience of this forest type, to undertake this atwly in cooperation with the oompet .. nt national experts, with & viev to providing preliminary guide-linea for their management, exploitation and treatm~mt.

The present report, which in our opinion oonatitutea preliminary guidelines, is the outcome of the otudy.

Louie Huguet D i l'tlator

Forest Resources Division ir.-l"efJtry Department

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AUTHOR'S BOTE

The terms of reference for this paper werea "Study the effects of silvioultural treatment and eXploitation method• in a moist tropical forest type on thtt qualitative and quantitativa composition and yield of subsequent repueration". A aubsequ.nt paragraph defined the f'oreat type u the Dipterooarp foreate of South Eaat J.eia.

It vas not f'ully realised ztil the atuiy vaa beS\W that it erabraoe• the tlbole gamut of manage~nent for these naturall7 regenerated i"oreeta. Thie wae not what I set out to do, and I ll&ke no claim to have done it eatietaotorily in eo abort a volUJDe. Ineotar aa I have brought together some relevant data and -.de variou auggeationa, I hope that it will be of' uae to others still working in the area, so that mana,ge•nt of these JMBnifioent for.ets oa."l beoome a reality even in the taoe of strong abort term pr~aeur.s that lead to their degradation and eventual deatnation. They are a God given heritage, with built-in means of' self-propagation, if we vill but take the trouble to follov the rul••·

~ oh ief concern i& that I have lett un•nt ioned the work of other rorwatere in eaoh ot the ooWltriea covered in the report. ~ only uouae ia the constraint ot a simultaneoWI full-tiM car.er position in QwJenaland Forestry. ICY a.pologiea are offered to theae workers, thougb thie doe• not right the vron&•

D.I. Hioholaon Atherton, Queena land

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TABLE OF CONTENTS

FOREUORD

.\tmiOR'S NOTE

SUMMARY.

1 • INTRODOOTION

1.1 Silvics of the Dipterocarpaceae

2. E'VOLtJl'ION OF CURRENT SYSTEMS

2.1 West Malaysia 2.2 Sabah 2.3 Sarawak 2.4 Rep. of Philippines 2.5 Indonesia 2.6 COGJHnt

3. VIRGIN FORFST CONDITI0l5 3.1 West Mal~sia 3.2 Sarawak 3.3 Sabah 3.4 1~e Philippines 3.5 Indonesia 3.6 Virgin Forest - Gene~l

4. U4'FEC'l'S OF LOGGING

4.1 Sabah 4.1.1 Tractor logging

4.1.1.1 Effects on the land surface 4.1.1.2 Seedling damage 4 .1.1. 3 Damage to advance growth

4.1. 2 High lead logging 4.2 West Malaysia

4.2.1 Ground logging ~~ethods 4.2.2 Cable logging

4.3 The Philippines 4.3.1 High lead lor.ging

4.3.1.1 Effects on land surface 4.3.1.2 Seedling damage 4.3.1.3 Damage to advance growth

4.3.2 Tractor dama&• 4.4 Saravak

4.4.1 Effects of tractor logging on l&J¥1 surface 4.4.2 Damage to advance growth from tractor loggi.Jl8

4 .. 5 Indonesia 4.5.1 Seedling damage 4. 5. 2 Damage tc ad. vance growth

iii

iv

vii

1

1

2

2 4 5 6 7

10

10 11 11 12 13 14 14

15

15 15 15 16 17 22 22 22 25 25 25 25 25 26 28 29 29 29 29 29 30

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~

5· YIELD FO~ASTS 31 5·, The stand table 31 5.2 Hates of growth 32 5.3 Mortality 32 5-4 Recruitment 32 5·5 Area 33 5.6 Characteristics of tree increments 33

6. COUNTRY PROJECTIONS 34 6.1 Rep. of Philippines 34

6.1.1 'l1reated stando 37 6.2 Sa.ba.h 37

6.2.1 Residua! stands 37 6.2.1.1 Untreated stands 38 6.2.1.2 Treated ata.nda 39 6.2.1.3 Comment 39

6.2.2 Seedling stands 40 6.2.2.1 Untreated standa 41 6.2.2.2 Treated ata.Dda 42

6.2.3 The total otand. 42 6.3 Sarawak 45

6.3.1 Residual etal'¥111 45 6.3.2 Seedling and treated atanda 45

6.4 West Malaysia 46 6.5 It¥loneeia 47 6.6 A rote on cnate 47 6.7 General aapecte 48

1· DISCWSION A:ID HECO)I)(ENI)ATIONS 50 7.1 The Philippines 50 1.2 Sa bah 51 7.3 Sa.rawak 52 7.4 West JCa.la_yeia 53 7.5 IJ¥ioneoia. 54

8. StniMARY OF RE>:ONMENDA'l~IOW 55 8.1 Onnoral 55 8.2 The Philippines 56 8.) Sa.bah 56 8.4 Sarawak 56 8.5 Weot Jlalayuia 57 8.6 ID.ioneoia 57

DmLIOORAPHY 58

APPEHDIX 1 63

APPENDIX 2 Oloaea.cy of Terma aJ¥1 COI2DOn Ham.ee 6t

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A general discussion on Dipterooa.rp ecology shows that they have oharaoteristio but good seeding habit a and that canopy disturbance is required before significant growth takes place. Seeding into a. logged otand is unreliable and every effort to retain aeedliDga a \ready on the ground has to be made.

An historical sect ion out linoa the development of the Malayan Uniform System and the Philippine Selective System and the similar systems used in Sarawak, Sabah and Indonesia. It is followed by a short description of the virgin forest, showing the general improvement in speoiea and tree size from West to East in the region.

Published a.nd other data on logging damage are given in some detail. Typical aftel'­logging stands are given, and these are used to forecast what future yields might be. By comparing the bef'0l'e ttJ",,l after logging stands of oolll'lleroial species it can be seen what a critical influence logging has on the productivity of' the rerM.ining stand. Coate are not dealt with critically, but avoidance of logging damage is seen as a very neoea.ary and satisfactory way of increasing yield under present conditions. Limiting tractor or oable daiDBge and marking for felling and retention are seen aa practical ways of doing this.

Treatment io aho~1 to have a mark6d effect on volume increment but should never be tho-ught ot .. aa a oure-all for poor logging praoticea.

In most cases selective logging is seen as a workable system, given better control of logging, and a minimal treatment ensuring crown freedom to all residuals is auggeated. H'owever, the need for prioJ' inventory data is atreaaed eo that (i) problem areas, e.g. thoae with poor advance growth representation, can be detected and possibly logged and treated under a. uniform system, and ( ii) to provide a basis for l"e&idual marking.

These ailvioultural aopeota of management are oeen as leas impartant than the major problem of protect ion of the foreat itself, against shifting cultivation aa wll as some legal, but ill-advised land uses.

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1. INTHODUOTION

'!be mixed Dipteiooarp Forests of S.E. Asia extend in a. broad aro from Southern Thailand through Sumatra, West Malaysia, Borneo, to the Hepublio of the Philippines. They fonA the main vegetation type on the western portion of the Indo-Malayan Rain Forest block (Whitmore 1975). Some seven species of rainforest Dipterooarpaoeae extend to New Guinea, but are generally of much less importance there th~1 in the west, even though thoy do cover large at~as (Paijmans 1976). These New Guinea stands will not be discuaaed in this paper but whel~ they occur with a high Dipterocarp fraction it is expected that most of the discussion ani oonolusiona will apply to them also.

Apart from earlier experience in Sabab and the Philippineo and literature oouroes, other data given in this paper were obtained in a short visit to West lalaysia., Sarawak, Sabah and the Philippines during January 1978. Tho\J&h a great deal could not be accom­pliahed in so short a time, very useful diaoussiona were had with various F.A.o. and country pereonnel. I was able also to judge bow much the oituation had changed from the oixties and early aeventies in whioh period most of my literatw'e aouroeo originate. It became clear to me that much or this literature was st).ll applicable. Logging intensity is still very much the same (though very variable). The relegation of forestry to tha steeper hill country was a change very notiooable in West Malaysia and Sabah, ami where the forest type changes significantly, some of the old data from the lowlands may not be applicable, but thie will be noted.

1.1 Silvio& of the Dipterooa~eae

Before discussing the development of logging and management syaterm in the variouo regions something o\J8ht to lJe said of the ecological requirennta of the family, and pa!'­tioularly of the regeneration phase. An important oharaoteriatio of the family ia ita irregular but abw1dant seeding (Wood 1956). This is coupled with a very short period of seed viability but a relatively long life of some of the seedlings. For example data from Sabah reported in Whitmore ( 1975, page 78) ohow that 1o% of' the 1961 recruitment was still alive after 9 years, a period quite lG·ng enolJ8h to bridge the seed year interval so there aT'e usually adequate numbers on the ground ( oee para. 4.1 .1. 2). Under undisturbed con­ditions these seedlin!)l'fl hardly grow with height inc1-ements ao low as 1.2 om a year (Nicholson 1965). tJume roua data show the rapid lUld rrarked response to increased hght caused by either felling ot• natural gap formation. Fox ( 1972, page 224) gives heights of 3 metres or more f'or seedlings only two years from felling and Liew & Wong ( 1973) eive similar data, Similarly moat of the growth data f1~m yield plots indicate very rapid seedling and aapling incrementa, e.g. 1.9 om/yr m diameter growth in 4 yea:t'-Old re~not'B­tion (reoearoh plot 45 in Fox 1972, page 225).

Though these data ind1oate a st1~ng positive ~sponee to light ths yow1g seedlings do not always appreciate expoaure in completely open oonditions. Thia ie shown both by experiment ( rlioholson 1960, Anon. 1964, page 6) and by observation (Nicholson 1970, page 3; Fox 1972, pag$ 228; Hutohinoon 1977, page 128). llot only is there a apeoifio diffel~noe, in that aome groupe are a lower growing and leas able to take exposure (Whitmore 1975, page 79) , but evf!ln the more intolerant epeoiee gro" best during their eutabliehmant phase in semi-shaded conditione.

However, ma.ximum survival and growth will ooour even in full light when moisture aml temperature &l'e not limiting (Anon. 1964, page 6) and thia indicates that the weather o:m­ditions at the time of logging and soon after will make a big difference to seedling survival. FNen germination io good in humid open situations. tlo other experiment o1• referanoe in the li·tera.tur.:t on thiu point has been seen, but it helpe to explain the once eXtensive areas in West Malaysia and S&bah, for uample, that vere densely stooked with young Dipterooarpa and whioh ware almost oompletel,y open to begin with aa a result of' logging follo"ed by sevel'e treatrae.nt, as provided by the Jal&yt:Ul Uniforn Syetem (see pa~. 2.1). (Large areas in the Philippines that originally w~re almost open, were a.loo seen to be oa.rrying good regeneration}. However, in general, the retention of aoattered shade

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provides good growth conditions for seedlings and guarde against excessive insolation or deoiooation in adverse weather.

This being said, notwithstanding, cnca establishment and early growth is assured, then the sooner one oan provide full overhead light the better will be the response. The experi­mant quoted in Anon. 1964, page 6, indicated that by 18 months all opeoies tested grew more rapidly in full light. Sastrosumarto ( 1978) quoting Soekotijo and Dickman ( 1978) oonfinns that once seedlings reach about 1 m in height they are capable of growing rapidly when fully released. Numerous observations show that the beat .JrOW'th or Dipterocarps occurs when there is a rapid retum to "fort!st11 conditione with complete soil cover but with the Dipterocarp component in a dominant position in the yomg canopy. (See also para. 6.2.2). This is likely toooour sooner than 18 months in logged forest because of the rapid growth of "weeds" that quickly provide soil cover.

In the above discussion it is assumed that the Dipterocarp seedling is already on the ground before disturbance and rttmains afterwards. This is one of the important prerequisites in their successful regeneration. EEperiments show that recruitment after disturbance has a higher rate of mortality and slower growth rate (for example, Anon. 1964, page 7; Liew & Wong 1973, page 11). It explains the importance of retaining these seedlings in any logging operation if auooessful regeneration is to take place. (See following, particularly pa.ms. 4.1.1.2 and 4.3.1.2). Thus tract.,r paths (snig tracks), and oableways must be kept to a minimum, as Dipterooarp regenerati\Vl on them is usually very poor because of combinations of initial deotruotion and slow recolonization due to poor soil conditions and laok of a regular seed fall. Sometimeo vine gl"'wth becomes so excessive here that new plants j\lSt cannot compete.

Reference will be made (para. 6.2.1..2 and others) to the inoreae3d growth of Dipterooarp advance growth in treated or logged areas. 'nle fact that seedlings 1-eepond very quiokly hae just been discussed 1 but the response of ativanoe growth is less easy to document. There are many measures before and after logging but f~w that are obtained from the same trees. Since this response is so important for any consideration of a polycyclic logging, proof that trees that suiVive the logging actually respond is needed. The following data from Anon ( 1964, page 20, and 1965, page 4) do this very well, I believe. There is no reason that this effect should not be oomrron to the other regions covered in this report, though the aotual order of magnitude will change with species composition and site factors.

Diameter inc. of 127 trees between 10 and 58 om diameter for 3 years prior to logging 0.4 om/year

Diameter ino. of the same 127 trees (all undamaged) for 3 yeara after logging 1.0 om/year

Nicholson (1965) ahnws that thie increase ocours in all the sizeo in the data. This ability of the Dipterocmrvs to respond differs from advanoe growth in some other aroae, e.g. Africa (Dawkins 1958&), and gives potential, other constraints allowing, to retain them as & crop in th~ir own right.

2. E.VOUJTION OP OUilREllT SYSTEJCi

2.1 Weot MBlaX!ia

Much has been written over a long ~-,riod on the development of logging and managermnt techniques in Malaya. Moat of thia oan be traced in the Malaysian Forester, or au.mmiittrized in MP.layan Forest Recorda !lo. 23 "llanual of Jhlayan Silviculture for Inland Forests" (Anon. 1963a). Wyatt-smith ( 1959) gives a brief but sufficient acoount of the development of the timber induat~ in West N&l~ia up to th~t date. At the beginning of this century the demand was almat entirely for heavy and durable woods suoh aa ohengal and marbau and

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for the valuable forest produot gutta peroha obtained from ta.ban meX'6h. This was still the position in the mid-twenties, though other lighter timbered species were being utilized, but not in proportinn to their representation 1111 the forest. The demand ro:r timber was increasing rapidly and medium powered sawmills were replacing the hand sa.wer in many at'eas. This led to the conversion of many more softer and less dlU"&ble species but even by the late thirties total exploitation was still light, with many of these speoiea being left or removed in ailvioultural trea.trrent.

After the war the demand for timber greatly increased and with improving sawmill technology a far wider r~ge of species was utilized. The oompleten~ss of utilization depended, however, on ease of aooess and closeness to markets and even by 1959, the more distant end less accessible areas were selectively logged whereas &Teas closer to ~rketa and of easy aoceas were almost completely utilized.

It was in these relatively light pre-war logging regimes that silvicultural experiments were begun. They led finally to the Malayan Regenere.t ion ln1provement System, which was Gmployed for a few years prior to the war (though individual experiments and :recomrnendationa were made as early as 1927 (Sangste~Davies, 1937)) and in the immediate post war period. It was, ill fact, the preoureor to the Tropical Shelterwood System which was adopted by some other tropical countries. In essanoa the system consisted of removing unde~rowth, unwanted understorey and some c&nCipy, irl a series of oleanings and fellings {or by poison girdling) lJafore the main oonuneroial felling. Though it was generally believed that these treatments aotua.lly induced regeneration ( Wyatt-5mi th 1959) , research and observations soon showed that the treatment was useful mainly in stimulating regenemtion already there. Even so, an integral pa.rt of the system, the "Seeding Fellings" oontinues to be ao calleda&

In &l'e&S where there was a demand for fi~wood, charcoal or mining timbem much of the unwanted underetorey was disposed of commerci&lly e.a 11 Corrrnercia.l Regeneration Felling&". Indeed in some richer f'oreats some of the final crop was taken out in this ·'i#ay also. Where these fellinge could not be nade conmeroially, Departmental "Regeneration Improvement r.,ellingott (H.. I.F.) were rrade with the same end in view. (Actually it waa only the smaller t reea to about 5 om diameter thAt wera felled. The larger ones were poison girdled).

These aub-ayeterre of the Mt.laya.n Regeneration Improvement System are mo~ fully desoribe<l in .:!lon. ( 1963&, page lli 3/1) with all the options &'\lailable to it a.nd contl'OlG neoeaeary. It led to large areas of vary fine regenerated forest, some of whioh can be seen today {e.g. at Sungei Bulch) but many were destroyed in the wa1• and others were on land later releaaed for agricultural development.

The interruption of the war with ita attendant widespread and uncontrolled fellinga whioh were given no ailvicultut•al treatment, was followed by a rise in demand for timber and a great increase in sawmilling. It was time for a "re-think'' with rege.r:i to silvi­culture and management. For one thing, many of these wartime felling areas oe..rx·ied go0d stands of young I>egeneration that did not seem to have auff'e!"9d from laok of attention, in faot they looked even better (Sti"U8Jlell 1947, Walton 1948, Wyatt-Smith 1959). For anothe1·, the demand. fol' firewood continued to fall, and thirdly, the re.pid inoreaae in maoh&.ll ... zation of extraction with ita high capital costa necessitated larger volumes per hectax-e of' ~'ellcd fol'eSt (BUI•geaa 1970). 'lbeoe faotors finally led to the adopt ion of the r.Blayau Uniform System. This ia again fully defined in Anon. ( 1963a, page I.ti 4/2) but for the purposes of this paper it ia the 1-emoval in one operation of all the economic crop f'lXlm are!iLa that ha.ve been shown by sampling to ca1•ry an adequate stocking of 1'9genero.tion- This logging is to be followed inwnediately by a poison gilv.ling of all the k"'errai.ning uneconomic canopy and all a!T6ller treeo down to about 5 +.o 15 em diameter, eXcepting oornmeroial epeciea of' good form. '1"'11is very d rae tic treatment ('iefinite ly favoured the quicker growing mel'Elnt i type t irnbei'S a.t the expanee of the he~vier ha.t'dwoods, but it was hoped that enough of these would be able to awvive a,&d grow, and this u.aually was the case.

Aa a researcher it is a littl~ dia&ppointing to see the way in whioh a management ayotem oan be so completely moulded by economic conditione rather tl1an by observation and

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-experiment in the forest itself. Undoubtedly there were auoh observations and experiments (e.g. Walton 1933, Durant 1939) but the ma.in stimul\U has come from the belief that meoh­aniA'1&tion necessitated the removal in one operation of all the crop trees. (Numerous authors e.g. Anon. 1963~~, page ni 4/3; Burgess 1970, Wood 1976). Reaearoh, rather than pointing the way, ha.a given ita blessing to the way already taken on economic gromds. It is interesting to speoulat.e •mat would have been the deoieiona +.aken had the light and medium he.nl\'Joode (i.e. the bulk of the sawmill raw material) really required nursing under a ehelt6rwood before final release, i.e. had not been able to tolerate a complete logging. (See also Wyatt-smith 1959). Fortunately this was not the oaae, and at the time the Malayan Uniform System appeared to be the answer. The swing to it was, however, so complete that it w&s applied to all types of forest and some failures occurred.

It is interesting to add here, that there io no mention of logging damage in any of the Malaysian literature that I have seen, as a reason for ohooaing a uniform system after the reasoning of' Dawkins ( 1958). Briefly this was that the amouut of damage done in logging tropical rainforests was so severo that the bulk of the following crop ha.a to originate from seed lin~s present at the time oi' logging. Advanct'! growth wa.s accepted but was not relied on for the next out, nor were special measures taken to preserve it from damage. It was rees1ued as a bonus, tho~h some, e.g_ (Wone 1966) have argued tba.t it should be removed in silvicultmoal treatmmt. In eome stands at least, tl1e a.dva:noe growth was reoognised as the probable producer of the neXt orop, Wyatt~mith and Foenander ( 1962). The )talayan Uniform 3yotem, when applied correctly was a viable ma.naRement tool and ll'IM.Y thousands of hectares were auooeanfully l'egenere.ted by it.

Later developments appear to have been controlled very largely by economic considera-t ions without tho oorresponding booking of technical know-how. For example, planned rural dovolopment is rapidly OOllVerting good lowland Dipterooa:r-p forests to agricultural pursuits, and pernw.z·H~nt forests will eventually be l'eStricted "almost exclusively to steep terrain of d iffioult e.ooesau ( F.A.O. 1973, page 9). 'ntis has had ·very aerio'U.S ooneequenoea on austa.int:,d yield management, very lareely because little experimental work had been done in these areas, whioh wet"e fo\llld to be much rno:rre difficult to regenerate (Burgeaa 1915). tlevertheleoss, thttae areaa are being r&.pidly opened up despite the pl"oblema. Tho\J8h thia ia an unfortunate aituation anti should not have been allowed to happen, I believe that with adequate input or fu.nda and rM.npower for proper logging and perhaps regenel"ation t l~a.tment, these fot·eats oan be properly managed for continued production. We need to develop, and l believe we oan, logging methode that are economically ~ eil•Jioultura.lly uound. Bl"igham'a { 1971) work in the Philippines showa that good ata..nda can be retained th~ugh high-lead logging when this is px·operly undertaken and superviaed. In thia oonneotion a lao l.e.ibWldgu't ( 1976) haa some pertinent :rema.rku. ~"or example (page 13) "Silvioultux·al ft-eedom of deoioion in selecting tx·ee apeoiea, tendi.ng aud regenerating techniques baaed on biological and economic oon­eiderationu should ~ uafegu.a.rdad. 'lbe oharaotet• and intensity of the intelVentione should thel\1fore nevax· be allowed to be detennined by harvesting oonaidere.tionsu. Again on the ae.me page ho aays "0pe.ra.tional rrethods have Ro fat• been roost ly uaed to decrease the oosta of harveoti.ng ••• In f···;.; Ul'e they should inoreas~gly be uaed also as a means to reach ailvi­o.u.ltu..:ral goa.le. Cutting trees io therefore in the first place a ail•1ioultura.l ta.ak.t'.

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2.2. Saba.h

The early hiatory of the logging induat ry in Saba.h is ffiVen by Fyfe ( 1964) and l'artyn ( 1966). Up to 1952 !'eal control of fo\'est exploitation wa.a ill the hands of the .British Borneo Timbe1• Co. (B.B.T.) which was formed in 1919, with a monopoly of all tirnbe1· exports. Other firma were allo\led this right on the payment of a oeas to the monopolv holder. However, dttspite the dangers inherent in monopoly Wldertakinge, they pushed. ahead w1th building up the tra.d.a and operations atea.dily expanded both by B.B.T. and by other tributa.:y firma. In the early twenties they introduoed h~gh-lead logging to an area being worked we at of Sandak.an, and though apparently auooeasful ror some yeara, wae "before ito t im.e'' and oould not oompete with hand logging rnethoda ( Kuda-kuda) using cheap labour. In general logging was highly oeleotive being oonfined mainly to floaters, and to the few timbers th&t wore well known. (tlaoorda of the B.B.T. higb-lead logging axperiment indicate

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an almost complete utilization or at least arNh higher than usual. at that tiraa, and it is suspected that the disposal of many of the lesser l01own logs could have been a problem anci contributed to ita abandonment. See also Browa 1950.)

After 1952 there was a great increase in logging ~dth the entering into the industry of three other large overseas finns and later by a further eight looa~ :Jompanies. Almost all of this effort was for export logs as the local demand was so small. By the late fifties almost all logging of any significanoe was mechanized with most firms using crawler tractors, and two also using high-lea.d systems in rather more rugged country. A full account of one operations' logging~ fairly typical of the easily logged east coast areas, is given b~ Nicholson ( 1958a) with particular emphasis on damage. This can be com­pared with a aimilar paper by Fox ( 1968) showing that the industry had continued to expand with heavier and more powerful l'l'l>'iLOhine-:~y being uaod. This expansion has continued intc the seventies and huge areas are now t1·i"lg felled. P.roduotion in 1977 was 14 million m3 coming off about 162 000 he.. As in West Mblayaia. there is a strong demand to develop much of the suitable forest land for agriculture and much of this huge volume ia coming oft such land. There is apparently still atJ.ffioient State land in the central and southern mountain­ous areas to compensate foi' this loss of permanent forest, and ita reservation is in progress. Muoh less is known of its potential, and silv7.cultu:ral requirements. logging should only follow oaraful investigations of these aspects as well as those dealing wit~ protection and water supply.

ln Sabah, with similar foreste ~o West Malayaia and very often with senior personnel with Malayan experience, it wao natural that the system of management would be the ~alayan Uniform System. The first areas were treated in 1955 and for a number of years there was a l'&pid expansion of treatrrvjnt into all major logging camps with annual areas such as 13 500 ha being treated in 1963. Two aooounte by Nicholson ( 1958 and 1965) cover th>l,t treatmentA applied and results obtaii1ed. Some divergenc~ from the mothet:· eystem in We·~t 18laysia followed experimentation in Sabah, and led to Sabah Forest Record tlo. 8 (Anon. 1972), but in the main, treatrrent in the two co\Ultries was very similar. These divergences centred rM.inly on the importance of advance growth for intennedia.to yields and the reduction of logging damage to them.

With the huge expansion of the annual coupe in the late sixties and early aeventias it wae impossible for si lvioultural treatments to keep pace anrl a large backlog nf w1treatcd forest has accumulated. In ear·ly 1977 all t l'fla.tment was ntopped, after the appearo.nce of a paper by Chai and Udarhe ( 1977) which ca.at doubt on the uaet"ulnase of treatment ooneida't'ing the very h it_;h rates of da.ma;rQ being caused in cur1-ant logging.

2.3 Sarawak

'I'houeh email scale logeing in the hill (but still lnwland) forests occurred before the second world war, the timber in<lustr,v relied mainly on the ~xt,.msive areaa of lowlarld peat swamp forests. B,y the mid sixties tho effects of depletion of these forestR becan~ evident And sustained logging in the hill forests was begun (Hutchinson 1977, t:age 1). A laree pl"oportion of all pl'Oduction is exported, and export figures ei'le a. good indioai. ion of the growth of the forest L&du.stry. H'1tchinson { 1977, page 30) shows exports as rioing from 47 700 m3 in 1950 to 4 348 000 m3 in 1970, and falling back to 2 212 000 m3 in 19'75· In tha ow&mpi'l, logging is by hand methods to a light rail and then usually to river ~ransport 1 while on Jthe dry land forest a.reaa all logging ia by tra.otor to road haulage to (in root oaaeo) ri.ver tt'Wloport to the shipping pointP.

All logged swamp forest areas have been t1~ated by the Malayan Uniform Syatem (Lea & L&i 1977) and though regenel'6tion of ramin has not been a sucoeaa there ia usually good regeneration of other oonunsroial SflE,Icies, eapeoially of a number of apeoies of awamp me1~~1ti (Lee 1978).

()}ly experimental (though significant) areas of dry land forest have baen treated, ev4ln though large areas are now being logged (probably of the o1.jer of 40 000 - 50 000 ha ea.oh year). In view of the gener&lly favourable reports from other traditionally ttJruSn

- 6-

oountrieo and their own experienatJ in the swa.mp forest the reasol'B for this diffidence is not olear. Possibly the lighter intensity of logging and the large areas involved were contributing factors. However. experimentation both by the Forest Department and by FAO personnel is currently being mdertaken to determine tl1e logging and treatment regimes for .SSrawak.

2.4 Rep. of PhiliRJ?illeB

The rate of logging appears to have followed a similar pattern here to Malaysia tho\J8h begiru1ing from an earlier date. l<"'igures from the Bureau of Forest Development quoted by Serevo ( 1949) and l!:tldacott ( 1977) show nearly a. five-fold increase in produotion between 1948 (2.4 million m3) Wld 1968 {11.4 million m3) with a slight but irregular fall after thia. It is interesting to note that the peale figure reached cnly 20 years after

3 Serevo ~n-ote, is already more than his estimated sustained annual yield (of about '1 mill m which he admits was only a conservative figure). Theoe data oerve to show that here to!? a huge in{'l"ease in exploitation has taken plaoe. Present production io about 8 million ~ (Sema 1978).

In oontraot to the Malaysian al'ee., mechanization of logging ooourred earlier a.nd w.a ~11 developed by the mid twenties, thoU&h hand and animal methods continued to be used in small eoale operations. Because of the oteePlees of much of the country, the high volumes and pooEibly the influence of We at Coaat North American lumbennen, high-lead logging systems went common, at first using stream yarders. However, tr'UOk lngging (Bataan method) using a military type "oi.x x six" truok with strengthened chassis, because of the relatively low investment needed, became very oomm:m a.tter the 2nd world war especially on the areas of gentler terrain. The method is very similar to the San Tai Wong of Malaysia.

Prom quite early on, ~porta of the destruotion being wrou.ght particularly by high­lead ayat~ma, were numerous, e.g. Brown and Jethewa pt•ior to 1920 (in Reyes 1959) , Daoa.nay ( 1923), Sel'tivo ( 1949). Logging appeara to have been controlled by a diameter limit ot .. the order of' only 50 om whioh •Y explain the oometlii'~S excessive damage reported, :~or example, 6f1'/:, denuded on some high-lead aettinga (Sel•evo 1949). Wyatt-smith ( 1954) a.lao points to the heavy riamage being caused to the reoiduale (hut not to the aeed lings) by hieh-lead logging, and it ia clear that the oonoern being voiced was justified. It was aggl'&.Vatod by 3\nfting cultivators (Kaingineroe) who prefe1•red heavily devastated land for the1r Padi. 'Ibio oonoem finally led to the Selective lngeing System currently employed. It seems tha.t fierevo wa.o among the fil'8t to aotually suggest the planning of 1-emovala to leavG a reaidua.l attmd and to assist its growth ( Serevo 1949). Jle a lao pointed out by a quote from Kol'Oloff ( 1938) that aa far as poae..t.tJ~.~ oilvioultural praotioe ahould be implemented through the loggiHg operation. (Seo also U!ibundgut 1976). Though probably not entirely poaoible in tro~ioal rainforeot thia idea helps to explain the almost complete lack of any aubaidiEUj' regeraertation operations or proposals for them i.!l the PhilippitleB, The Seleotive l.ogglng Syatem ia deoorib•:1d in detail in 'nte Handbook on Selective logging ( 1965a.) which is an ela.boN.tion of He;,-es ( 1959) who givou muoh of the baa.i.o fo1• it and its chief oharaoteriotios. In brief, t!&ey are that=

( 1) following a 5% sample a 11ertai.n peroentage of t.ea.lth,y young oommeroial treeo are marked and mu.ot remin Wtd~d tht'O~h the logging opel"&tion. The original 1~qvirement wail 6C!f.> of all ouoh t l'eeB in the 15 - 15 om ai!!'.ie range or in the oas~ whel""e there was a heavy stand oV'lr 75 om diameter (mo1•e than below 75 om) t~on 5o% of all commercial t1~ea over 15 om diameter we1~ to remain. Apparently abWlea in awuicillg, perhaps because tho .range waa not sub­divided allowing rroat marking to be done at the loweJ' end, led to a chango in 1973 (Admin. Order No .. 74) -..hereby 70% of' the 15 - 61) em t1-eea plus 40% of the 65 - 75 om trees h&.d to be ma1'ked for undam&8~d ret ant ion.

( 2) All oort'marcial t reea over 75 om were to be taken in loeging plue 7\1}(, of the 55 - 75 om trees. The same Admin. Ol'der oh8J18ed theae limits aloo to 25% of the 55 - 65 om trees plus 55% of the 65 - 75 om t~us plus all over 75 om, again apparently in an effort to l'etl6in more of the px..:~~nt crop and to do leas felling damage.

- 1-

(3) The residual inventory after logging, as a 100% oount to detennine the numbar and oondi tion of the residuals. This provides data for asseasi11g fines for damaged trees and for estimates of future yield.

'The writer had the opportunity to study these rules prior to the promulgation of Admin. Ox'Cler No. 74 and made some suggestions for change (Nicholson 1970). These were that a number rather than a % should be set as the minimum marking goal (which would tend to upgrade poor areas) and that the felling limit should be 70 em and above. Though these were apparently not taken up, it is of interest that the felling limite set in 1973 approx­irM~te V•BI"'J closely to a simple 70 om limit, for average diameter distributions. It is agreed that some cutting in the 55 - 65 om size oould be beneficial but Wlless oloaely watched, abuses such as takillg the bas+ ?.5% rather than the worst, could ooour. ~imilarly abuses could ooour in the 65 - 75 range but there aa 41J% shtmld already have been marked as residuals there is a built-in safeguard, and as will be shown later (pa~. 6.1) it is important to keep good residuals in the upper classes for better yields.

Up to date no extl"a silvicultural treatment has been done on a routine basts (experi­mental areas all show its efficacy as in other comtriea) and \Ultil recently this perhaps was the biggest difference from the Malaysian scene, in reapeot to the appearance of the regenerated stand (Nicholson 1970, page 24).

With a large looal demand for wood and wood produnta, large industrial complexes have been developed in a number of places which px'Oduce sawn wood, plywood, chipboard, hardboard, pulp and paper. This is being actively encouraged and restrictions in log eXports are being put into effect. The forest yield of loge to supply these plants hao been set ~ery ambitiously and there are now indioat ions that other oouroeo of logs may be neoeeaary to ensure supply at the C\\rrent and designed mte. Supplementary planting {preferably on grassland a1>eaa) may have to be developed on a large oaale for this 4'e&Boo. At least one large company io planting (within its oonoeooion area) very significant areas (Tagudat• 1978). This subject ia discussed agau1 ill para. 7.1.

In Indonesia. with over 100 million ha of forest, a la~t-ge part of it valuable Diptero­oarp fol'eBt, the rise in exploit at ion has been even more spectacular than in any other S.E. Asian country. Soedjarwo (1978) gives 1969 ao the beg~~ing of large scale mode111 logging operationo and that oinoe that time timber haa become the aeoond la.-reeat ea.tne::• of foreign exohange. However, as late ao 1978 the beat area fitrures are the; 1')29 oneu of atdert (Hamzah 1918) who gave the foreot breakdown aa follow~H

Permanent Foreato Production Protection Wildlife sanotual'ieo etc.

Sub Total

To be alienated

TOTAL

38 000 000 ha 57 000 000 ha

3 000 000 ha

98 000 000 ha

22 000 000 ha

120 000 000 ha

Hanm&h ( 1978) gives the 1974 log export a.u 17.5 million m3, a huge figuN. He aloo shows that abcut 11 million ha have already been allocated and awarded ao timber oonoeasionu with a further 43 million ha under applioation. Thus ovet• 60 million ha of oonoeasion ia poooible. Sedionc ( 1914) gives 44 million ha as the area oar~Jillg sufficient volwre for exploit at ion. There da.ta show the sudden realisation of the val\U' of fr. r.,..sat exploitation in recent years, but alao i."ld.ioate the gre~t d.anger of insufficient planning and regule.tion, in manaeing such a. hUe."'"e resource. The need for proper control was neen early ill the boom period and it will be of value to quote in full Soerianegare.•e ( 1970) e~l'Y of his

-8-

definitive paper on ailvioultural control, as follows:

"To prevent the degradation of natural foreota due to lat•ge soale logging. oArt~in eilvioultural systems should be applied in conjunction with cutting regulations.

Based on a study of tropical ailvioultuml systems and considering the results of recent investigations on the effects of manual and mechanized loeging in Sumat1~ and Kalimantan, thb author came to the conclusion that:

1 • .Enrichment planting as line, strip or plot planting systems should be done now in out over areas.

2. The next step iH to apply one of the suggested ailvioultural systems, i.e.

0

( 3)

a.) '!be modified selection system:

The Indonesian modified selection syatemj The Philippine's selective logging.

b) The modified lil.layan clear felling or uniform system~

The outline of the Indonesian modified selection system is the following:

( 1) Foreot and regeneration inventory should be conducted before logging ope111.t ions.

(2) Trees to be out and t1~ea to be left as aelected trees should be marked:

ab) Trees tn he out should have a diameter above the defined limit. ) The amount of the selected trees depends on the diameter limit

and th<J rotation or outting oyolo ao follows:

! Amount of Diameter of I Diameter limit Cutting orolo ~f!locted t reea eel~oted trees (om) (years to be left _(om)

50 35 25 ') 35

40 45 25 )35

30 55 40 )20

After t:'ne ope: :re.tiona.l unit haa been logged the following aotivi ties ahould be oond uo ted:

a) Residual stand inventolj':

(1) The selected trees ar~ subjeoted to a { 2) other t reea of the residual at and are

100% inventory. it1ventoried by sampling.

b) Cleaning of weeds and climbers to free rep1"0duotion of commeroial forest treeu.

o) Restocking of open areas and poorly stocked pa.rts of the residual stand.

(4) Five years arter the logged area han been aband~~ed tending ope~tiw1s should be done, comprising:

a) Cleaning to free reproduction from weeds and olimbere.

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b) Restocking of poorly stocked parts.

o) Thinning if necessary.

The outline of the modified 14a.le.y&n uniform system is as follows:

( 1) Inventory of trees and seedlings of commercial species, 1 - 2 years before logging.

(2) Felling of Wl operational unit is directly followed by poisoning of weed trees.

(3) Five years after logging the following should be done:

a) Regeneration inventory of saplings and poles of oommeroia.l species.

b) Hestooking if neoessa.rJ.

o) Clea.nine; to free tree repx'Oduotion from weeus and climbera;f

d) If the stand is uufficiently stocked with reprt"'duotion of commercial tree sveoies, the stand can be designated as regenerated.

(4) Ten years after logging an inventory of trees and reeenere.tion should be oonductod. If necessary, tending opere.tions are done:

a.) Restocking of poorly stocked parts.

b) Thhming.

c) Cleaning to f1-ee tree reproduction from weeds and climbers."

Little comment is necessary, exoept for the following:

1. Enrichment plantinf~ ia suggested for all areas. I cannot believe that this is always neoeasar;y.

2. The Indonesian Johdified Selection System ia very similar to the Philippine Selective Logging System. Somo of the limiting sizes are different and M ad hoo table of numbero of trees/ha is uaed inatead of a percentage. Though I also suggested this (Nicholson 1910, page 39) it ia probahJe hia suggested numbex•a rmy be unattainable on many areas. It alao differs in that a oluaning treatment is specified as well as planting of poorly stocked are68.

Another important paper by Doerboom and Wiersu.m ( 1977) given a deaoript ion and comment on the fo1-est ry ope rat ions in Eaat Kalimantan. A reading of this paper indicates that many of the conditions there are very similar to thoae in S&bah. Qu~ major difference appears to be that shifting cultivation is more of a problem.

He indicates that the ailvicultural system to be applied oan be chosen by the company! He gives three ayatema but unites Philippine Selective L,gging with the Indonesian System (rightly oo} and gives the Modified Malayan Uniform System an artificial regeneration (plantations) as the other two possibilities. For various )."eaaons, among which are the greater degree of technical knowledge necessary and the lack ~r a. market for small lOBs the Mt.layan System io not applied, and V'!ry little planting is carried out either. However, he sees gr~at possibilities for the latter such aa:

ba) use or waste land;

) better volume prod·ootion;

do) better employment possibilities; and

) amenable to Asro-Foreatry aohemes. (See later undej' para. 7.1.)

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The authors agree that the Indonesian )bdified Selection System is basically soWld but implen:· -~ation is rarely practised. They stress the great lack of trained staff on the gro\D'ld makHlg it impossible to enforce the regulations.

2.6 Comment

It can be seen that two types of cutting systems have been ~valved in the countries dieouaaed, and though as intimated above there is often little difference in the after logg1ng appearance, there is a major difference in the oalculati~n of yield. Intermediate fellings in the M&layan System have not been fully specified as yet and all residuals are expected to last the whole rotation of about 70 years. Thinnings were recognized as being necessary but on present utilization standards oould not px·ovide much revenue. They were postulated at 20, 35 and 55 years or only at 20 and 55 years. The system then is olearly a rMnooyloio one with eaoh area being hatvested onae in a rotation. (But see recent trendo in 4.2.)

The Philippine and Indonesian Selective Logging Systttms, however, rely heavily on an intermediate yiel~, i.e. is polJ~yolio or bioyolio einoe no more than two harvests per rotation are usually suggested. However, Endaoott (1977) does postulate a very short cycle of 10 - 20 years in maintaining his "ideal" stand table. It ia not clear whether he means thio to be used in practice. ~ own views as previously stated (Nicholson 1970, page 30) are that Dipterocarpa need a. heavy logging and then a long period of closure as can be provided by a bioyolic system. The yields must be set realistically, however, and b~ baaed on ao\Uld inventory and growth data. It is believed that the difficulties being foreshadowed b,y the industrial complexes mentioned above, originate very lare-ely rrom thia oause. At the time, Selective Logging was seen aa a wnrkable aystem with cutting oyoleu of &bout 35 years which would give seoond and subsequent yields similar to the firat. The evidence was and otill is vecy scanty on this point. Factors are logging da.mago and stands poorer than hoped for. Since in theory 1 at any ra.te, yieldu can be nearly twice thooe of the Unifonn System {cutting twice the area each year) it does have ita apPfral and oan bring more forest into an actively producing condition in a aborter time. However it may be necessary to impose limits on the first out in the inten;,sta of those that follow.

Muoh haa been written on the merits of both these systems (see for example Whitmore 1976, page 81, Lealie 1976) and no purpose will be served by going fully into them now. It ow1 be noted that the bioyo lio syatem ae preaant ly UDod in the l1hilippinea and in some othel' areas, reverts to what Varulie~ ( 1975) calla a "Stratified High-Forest", or a two­tiered "Wliform aystem. In prt\Otioe and as will be shown in section 7 both mno and bioylcio regimes will have their place in Dipterooarp silviculture depending on the stand structure just before logging, whether it be the initial or subsequent outs.

3. VIRGIN FOREST CONDITIONS

Before looking at the effects of logging it will be helpful to study the original atand structure and how this varies from country to oountryv UnfortUllately there baa not been any Wlifonnity in recording of data nor in ita preaentatiou, and eo it is difficult to compa~ stand tables given by various authoro. ln the tables that follow the size classes as originally reported are used,, with the equivalent rretr1o diameter given for those reported in feet or inches, and all numbers have beon converted to a. per hectare basis. (To avoid ambiguity in the rmtter of size olaaaes the upper and lower limits are given. For example, in the Philippine work the 10 om size olaseea centre on the "ten au ao that the 30 om oleos runs from 25 to .35 1 despite my auggestion (Nicholson 1970, page 10) {" . ..-r the o laos to be with in the one ''ten" so that the 30 om o laos would run from 30 to 40 om. Some r.r the early Philippu1e studiea were oo repo1~ed (Brown 1919) and it is a pity the Hyatem wa.a not oont:l..:wed.). To eive aome directly compa.ra.ble da.ta, estimates (by intel'­polation) of the data over certain diameters or in oertain size l"&llgea, have been added to eaoh table.

- 11 -

~1e weieht or value of eaoh set of data varies greatly end the basis of the sample has been ~iven where blown. Appt~ximate altitude oan be given in some cases aloo. Even in ·~~est J.Qlaysia. where distinct altitudinal changes in forest structure and species com­position have long been reported (Wyatt-Smith 1960, 1961) their national Forest Inventocy doea not appear to have diffei-entiated between them, at least not between Lowland a.nd Hill Forest which change occurs at about 300 m.

).1 West Malaysia

Surprisingly perhaps not a great deal could be found in the form that was useful fnr comparison without a great deal of secondary compilation. However, from an extenaive set of tables (u1 FAO 1973) were compiled the following two sets of data. The first set iu a mean of 56 - 3 acre ( 1.21 ha) plots, in 11Good Hill Forest". The aeoond set is a meWl of 81 plots of the same size in "Model"Qte Hill Forest". The inventory has these data grouped in industrial ~ones but the.above means&~ weighted to take acoount of the areas of these zones. The term "Hill Forest" refers to dryland areas, i.e. not swamp o:r mangrove and should not be oonfuaed with previous Malayan usage where :\t applied to an altitudinal zone roughly between 300 and 760 m above sea level (see Anon. 1963a, page III 7/20 for a fuller description of this forest type).

TABLE t. West )alaysian Stand Tables (see teXt)

Diam. class jn. om. - -6-12

1?-18 18-24 24-36 36-48 48+

15-30 3()..46 46-61 61-91 91-122 122+

Total 15+ Total 20t Total 20-80 Total 80+

3. 2 Sa.rawak

S~t 1. Good Hill Forest

All

152.0 46.7 21.9 14.7

2.9 1.4

239.6 188.9 179.2

9.7

No.:..{ha '

Dipts.

11.6 6.5 4·7 s.6 1.7 1. 1

31.2 27.3 22.5 4·9

Set 2. M:>derate Hi 11 Fore at

All

159·3 46.7 19.6 12.4 2.0

.'{

240.7 187.6 180.3

7.2

No. ha. Dipta.

12.1 5·6 4.0 4.1 1 • 1

·4

The following set of data waa taken from FAO ( 1973a). Aaain a aeleotion of data had to be made between eight :a.asesaed unite. 'llle one ohoeen had data most like the mean of all eieht units with regard to volumes and topography, and was unit 4. Within this unit, these subdivisions have been weighted according to a1-ea and ~&ned to give Table 2.

TAllLE 2. Sft.rawak Stand Table (aee text)

Diameter Clans 11o. ha in. em. All Dipta. - -B-12 20-30 94.1 31.5

1 ?.-18 30-46 64.5 24.8 1&-.24 46-61 24.0 12.9 24-36 61-91 15.1 10.9 36-48 91-122 2.1 1.8 48+ 122+ .24 .21

Total 20+ 200.0 82.1 Total 20-80 192.2 76.1 Total 80+ 1·9 6.0

- 12-

3.3 Sabah

Ql the face of it, there seem to be more data from Sabah. Some are given in Table 3 following. '!bey show the great variability or these forests. The table footnotes give the authority and other partioulars for eaoh area.

TABLE 3. Virgin Stands in Sabe.h - All data are no./ha (see footnote*)

Size Class 1 2 3 4 5 6

Girth Diam. All Dipt. All Dipt. All All Dipt. All Dipt. Dipt. All Dipt. All ft. om. Co nun. Cornm.

1-2 10..19 205 11.6 269 21 21 405 77 156 21 15.6 208 43 53 2-3 19-29 62 8.2 82 15.8 25 133 36 59 11.) 9.2 69 17.1 20 3-4 29-39 21 4-7 20 4.4 5·4 62 25 17.6 4.9 5·9 32 10.3 11.9 4-5 39-49 17.5 7.2 14.1 4-9 7-4 22.5 10.0 1).4 3·9 5·0 24 6.6 8.5 5-6 49-58 11.4 6.4 1).8 6.9 8.9 12.1 5·5 9·0 4.6* 4·3 9·3 4·1 5·3 6-7 58-68 9.6 7.2 6.4 4.8 6.2 8.9 6.0 5·5 3.7 3.2 6.2 2.3 ).3 7-8 68-78 6.4 5·4 4.0 1.8 3-5 5·9 5·5 4·5 3.5 3.3 4-3 1.8 2.2 8-9 78-87 3.4 ).2 2.3 1.5 2.2 3.2 3.2 ).8 3·3 2.5 2.5 1.0 1.4 ~+ 87+ 11.0 9·5 10.6 8.8 10.6 1).3 13.1 9.2 8.4 9-8 8.2 6.4 6.8

Total 10.. 353 63 422 70 90 667 181 278 65 59 364 93 112 Total 20+ 143 51 145 47 67 249 101 116 42 42 149 48 57 Total 20..80 129 39 133 37 55 232 85 104 31 31 138 41 49 Tntal eo.. 13.6 12.0 12.0 10.0 12.0 15.8 15.6 12.1 10.9 11.8 10.1 7.2 1·9

2. Nicholson 1962: Typical lowland forest on shales ~1d sandstones, forest type B. Nelasoope data. (Research plot 54)

3. Nicholson 1 6 : Lowland forest on sharply ridgad sandstone 1 forest type G 1 area 1. 2 ha. Heaearoh plot 17)

7

Dipt.

27 18 9·9 6.4 6.4 4-0 4·4 5·2 9·9

91 62 49 14

4. Fox 19671 :-lamo area as ( 2) above. Data l .. or sizes up to 58 om from 2.83 ha and for ai1.es over 49 om from )1.89 ha.

5· Fbx 1968: Same area as (2) and (4) above. A~a 6.2 ha.

6. Liew & Juin 1976(?la Hill forest of the Interior. Altitude for individual plots ranged from 427 m to 732 m. Soil t .. rom sedimentary rooks(?). Area sampled totals 4·9 ha, forest type D.

7. Chai 1978: Probably of forest type 1", at about 550 m elevation. Area 4 ha.. (Furthel' data to be published by Chai).

- 13-

3.4 The Philippines

~ly two sources giving ~·irgin stand oompoaition were found, though doubtless others must exist considering the number of botanists and foresters who have worked in the oount ry.

Revilla (1976 from Reyes 1968) gives vi~in figures for the four climatic types of the Philippines, as recognized by the Bureau of Forest Development. These are given in Table 4·

TABLE 4• Philippine Virein Stand Table - No./ha

Ty£2 1 ' Ty~~- 2 TyJ~ 3 TY,Je 4 Diam. Cla.os Total Dipts Total Di.pta Total Dipta Total Diet a

5-15 283 119 282 64 267 05 503 124 15-25 1?6 47 130 38 122 34 149 31 ?.5-35 62 33 68 25 55 23 70 22 3~45 37 25 34 16 31 17 38 14 45-55 22 16 22 13 19 12 22 11 55+ 39 36 37 29 32 27 25 10

Total 5+ 569 276 573 185 526 198 807 226 . Total 15+ 286 157 291 121 259 113 304 96 Total 20.. 223 133 226 102 198 96 229 83

Weidelt (1976) giv&a data for 3 plota in E. llndanao in olimatio type 2, some of which are in Table 5 below.

TABLE 5· Virgin Stand Tables - E. Mindanao - No./ha

1 2

I Diam. Cla.ao All Dipta All Dipta - -15--.. 25 68 23 90 24 25-35 46 21 59 20 35-45 20 12.5 25 11.8 45-55 12.3 7.6 12.3 7.4 55-65 1·5 6.1 10.3 5·1 65-75 7.0 6.4 5·3 4·3 75-85 7.1 7.1 6.8 6.8 85-95 6.0 6.0 4·5 4.5 95-105 4.2 4.2 3.3 3.3 101" ,)'+ 6.4 6.4 5·4 5·4

Total 15+ 185 101 2?.2 93 Total 20+ 151 89 1?7 81 Total 20-80 130 69 160 64 Total 80t 20 20 17 17

1. Plots 1 and 2 oorftbined 1 both almost level and both at 100 m a.a.l. areas 9.9 and 7.6 ha totalling 17.5 ha.

2. Plot 3 at 600-700 a.a.l., moderate to rough topogmphy, area 21.2 ha.

- 14-

3·5 Indonesia

Hae~l (1978} gives the following data for productive virgin forest in Eaat Kalimantan.

TABLE 6. Indonesian Virgin Stands ( 1}

))iam. Class All -2<>-35 69 .. 02 35-50 38.56 50+ 35.75

Total 20+ 143.33

Commercial (Local)

11.82 5·53 4·45

21.80

No./ha

Commercial (Ex:portable)

27 ·95 21.39 25.91

75.25

Dipterooa1-pa make up 7c:JI, of the exportable apeoies, and 37~ of all trees over 20 om diameter.

Saotroownarto ( 1978} give& other data taken from nine oonoeaeions in East Kalimantan.

TABLE 7. Indonesian Virgin Stands (2)

Diu. Clasa

2Q-35 35-50 SOt

Tot a.l 20+-

No./ha Conmercial ( Looal & Ex,EOI'tab le)

32.3 14.1 46.4

92.8

'nleae ohow a muoh la1•gex• large tree stocking than the figures of Haoruma.n.

).6 Virgin Forest - General

The figures at the bottom of eaoh of the previou.a table£~ oan be ueed to nake oom­pal•iaono ~tween the cow1trieo. ~orne of' them have been rewritten in Tables 8 and 9• A few of the differenoeo that oan be seen easily are1

a) 'Ibe higher number of large tl'ee& in the Philippines.

b) The better Dipterocarp rep1~udntation there aluo. Fbr example, in the 80+ f:motion the percentage ()f Dipterooarpa ie:

Weat ·!!o.l~aia Sarawak Sa bah Philippineo 5

57% or leao 76% 76-98% 10~.

Similarly, for the medium size l'fU18e, West IBlayaia. show up te.ther poorly, aa shown in Tables 8 and 9·

- 15-

TABLE 8. All Species ComP!rison

Size Range (om) 20+ 20-80 80+-

West Malaysia 1 189 179 9-7 Sare.W'l.k 200 192 7-9 Sa bah 1 143 129 13.6

3 249 232 15.8 4 116 104 12.1 6 149 138 10.1

Phi lippinen 4 219 - -~hilippines 5 1 151 130 20

2 177 160 17 j Indonesia 6

I 143 - -

7 93 - I -TABLE 9· DipternoarE Comparison

Size Range (om) ' 20+ 20...80 80+-

West Malaysia 1 27 23 4.9 Sarawa.k 82 76 6.0 Sa bah 1 51 39 12.0

3 101 85 15.6 4 42 31 10.9 6 57 49 7-9

Phi lip~inea 4 104 - -Phi lip pines 5 1 I '39 69 20

2 I b1 64 17 Indonesia 6 53 - -

Thus without going into the data too deeply, it da~u t::t:em that the~ is an improvem9nt in the forest with rega.1'd ~('I size and Dipterocarp representation, when goiJ~g from West to Eaat. The !larawa.k data., and Sabah 3 (whioh io rega1ued as being atypical for Sabah) a1-e outstanding in the high number or medium aized Dipterooa.rp trees, but in Sarawak these do not oa.rry on to give a good large tree oount.

4. EFFmTS OF LOGGING

4.1 Sa.bah

4.1.1.1 Effects on the Land Surfaoo

Nioholoon ( 1958a) quoted a figure of 14',t for the lU'-ea bared by tra.otor "~raokEJ and landings {loading areas) but excluding main haulage lines (road or t'8il). Thia figure was thought to be fairly typical at the time but by 1965 oonoe1n about liruoh higher peroentfl8ea of auoh area~ waa being voioed (Nicholson 1965). As much a.a 4~ wu being quoted and this is confirmed by Fox ( 1968) who oh:lW8 43% as tl'80tor path (and preaurnably landings). Chai ( 1975) and Chai & Udarbe ( 197'1) also confirm thio high t'igure tho\l&h variability ia very high (Liew 1974, page 9). !lature.'!.ly this damage will have a aignitioant effeot on ~gene~tion.

- 16-

As has been shown above Seotion 1.1 growth of Dipterooarpe on bared soil or sub­soil in a logged forest is very uncertain and the area bared is effectively excluded from the forest in so far as it can support Dipterooarp oommaroi&l trees (see also Fox 1972, page 219). 'lbese high amounts of tractor damage also, of' oours~, increase the o}:anou of snig damage to pole sized advance growth, so it is doubly ilnpf.>I'tant to keep them low. '!bough no data have been collected it is believed that tree·s bordel'­ing these bared a~as can utilize them, if not immediately, at least after a nu~~er of years when their roots have grown and when the physical properties of the tnuks become more amenable through natural means (litter, maoro and micro-organisms, drain­age ate.). Fox ( 1972, page 219) indicated that 10-15 years may p&.ss before the t re.oks themselves become similar to undistur·bed areas. A plea by Nicholson ( 1965) in respect of Dipterooarpe bears repeating: "It cannot be too strongly at reaB4!d that a well reeeneraterl forest depends on a careful logging operation. 1\ll other limiting faotorn have been shown to be agreeable to almost a clear felling: only ex·tra.otior. has the potentiAl to reduce the regenerating forest to a ma.as of useless weeds, by destroyi..ne exi.st.ing seedlings &nd poles. The forest can tolerate a fairly high percentage of ita land surface being scraped ba.re so lone aa this percentage is scattered and mac.\e up of narrow logging roads. '!he most de at ruot i.ve damage appears to atem from inefficient use of traotor tracks, widening of tractor tra.oka to avoid boggy a.1-eas, and ~.arge oolleotion pointe near loading points ( landines) •"

Tbi.a ia of ooux~e very closely tied in with the amount of ba1~d areas and is u.aual11 not separate<.' from it, a.nd average at-,okinga befor.J anct after (for a few trialo) nr after logging only {for many trials) are given. Usually too, onll stocked milliaore*plots (.0004 ha) are uood giving a possible total of 2500fha. However, a few total m.\fl\ber oounto have been made auoh ao these from Anon. ( 1964, page 8) for virgin fore~1t1

NP 51 83 400 (1958) to 230 000 (1964) aeedli.ngs/ha RP 17 86 000 (fluctuates about this fi~, lowest 71 000)

and Nicholson ( 1958) where 25 000 aeedlinga/ha less than 1.5 m tall were found in traotor logged r"rest, ino1uding ~:~~.11 Wlig traoks etc. as they ncourred in the sample. (This oampl_, was i11 the same fol'Etat discussed more fully in the next section). Fox (1968) gives aom8 before and after milliacre*samplee, again from hi~ area discussed more fully in the next section:

llo. of mi lliaore pltlts atooked a) before - 1560/ha b) afteJ, - 554/ha.

NUJ'II~H·nue ria~ a frnm nt'ter logging assessment a have been reported in Anon. ( 1960-64) fJOI'llllt or which are in TOOle 10.

* 3tooking by ~nilliaore quadrata &a ito name suggeato was developed using 10 x 10 link quadrats (2.01 x 2.01 m). The quadrat ia regarded as bein.- atooked if one oommeroial plant is prea.ent. The size of thio plant hao va.ried. ~il different countries using the method but is usually l~otrioted to seedlings or saplings. Limiting the number to 1, sets the stocking U.mit as appro.xiiD&tely 2500 plantaj'ha., whioh is ample both for ~gene rat ion purposes as well as moat ai lvioultural experi~~ents. Besides speeding up any seedling aaaeasme.nt work it gives roore meaning to the result by avoiding bias from denee olumpa and brings in a apaoial measure ao well. 'Ibe system is fully deeoribed by Barnard ( 1950) for Weat Jli.l~uia and by Nioholaoo ( 1965) for Sabah.

- 17-

TABLE 10. Examples of Milliaore Stooking

Yeat•

1962 1963 1964

No. of localities Approx. area (ba} represented*

15 17 12

2 600 2 400 2 700

Unweighted Mean No/ha

750 740 950

.Range

1100...166 1200-250 2000-480

* At the rate of a z.fo sample. Some larg'Or areas may ha<.re been sampled at 0.5~ and so the actual areas represented are probably much larger than these.

Fox ( 1972, appendix 8} eives la·ter data very much in agreement with thee~ and in faot the mean of five &l"'e&a sampled in 1970 still show about 800 stocked quadra.ts/ha.

4.1.1.3 Damage to Advance Growth

Detailed analyses of tractor logging have been made by Nicholson ( 1958a) and Fox ( 1968) in the forest type quoted as data 2 in Table 3 and in the actual plots of Fox ( 1968) as data 5· It will be pertinent to re~at eome of their figures (converted to a. per hectare basis and with soma alight rearrongernent and addition of all standing tx-eea for comparison with West Jil.layaia and Philippines, where individual tree da~e has not been so closely studied. Oonvex~iona to only 1 decimal sometimes do not total exactly).

(a) N~cholaon ( 1958a) - 43.7 ha ot~ logged forest

TABLE 11. l/'l!{ging Damage Gonvneroial S~oies - Qirth (ft.} & Diameter {em) Classes

Total -Cater,ol'Y 1-t: 2-3 3-4 4·-5 5-6 1-6 1-6 6-9 Total % 10-19 19-29 29-39 39-49 49-58 10-58 10-58 58-8?

1 v No damage got)d 5·3 s.o 3·5 2.4 1.8 18o 1 35.4 2.1 20.2 34.8 2. No damage bad 1.6 1.9 1.1 ·5 I ·1 5·8 11.4 1.5 7-3 12.6 ). Bark damage only ·5 ·1 .6 ·5 I .3 2.5 4 .. 9 .7 3.1 5,) 4· Crown damage only 1.1 1 .I) 1.3 .8 ·9 5·7 11.2 1.4 7.1 12.2 5· C "" D damage ·5 I < .,6 ·5 I ·4 2.6 5·1 ·5 3.1 5·3 v·~

6. Standing t reea 9.0 ~-~ . f·( i 7.1 4.7 4.1 34.7 68.0 6.2 40.8 70.2 7. Fallen or broke.tl 5· ;. ·. ' ,. i 2.8 1.6 1.3 16.3 32.0 1.1 17.3 29.8 ~ 1 . ' I

8. 'rol'AL 14 .. :, 1 ·; :J • 0 i 9·9 6.3 5·4 51,0 100.0 7.3 58.1 100.0 . I I

Note - Add 3 and 5 for total l'a.rk da..ma.ge &hd 4 and 5 f. or total crown dam.age

- 18-

(b) Fox ( 1968) - Each table baaed on 8.1 ha

( 1) All .,limbere out 3 yeare previously

TABLE 12. _1~ging D!!!«! CoMeroial Speoiee - Girth (t't.) & Diuet•r (om) Olaaeee

:rrotal

"' Category 1-2 2-3 3-4 4-5 5-6 1-6 1-6 6+ Total tJ, 1D-19 19-29 29-39 39-49 49-58 10-58 10...58 58+

1. No d~e ).7 2.0 2.3 1.6 I 1.4 11.0 )0.7 1.5 12.5 31.8 2. Bark damage only - .1 - .1 - ·3 .8 .1 ·4 1.0 3. Crown d~ only 1.5 ·9 .4 1.5 .6 4.8 13.4 (' •:> 5·3 13.5 4• 0 &: B damage ·5 ·5 .6 ·9 1.1 ).6 10.1 ·4 4.0 10.2 ~ • Standing trees 5·'1 3·5 ).4 4.1 ].'i 19.6 54·7 2.5 22.1 56.2 6. Pallen OI' broken 7-5 4·3 2.3 1.2 .. , 16.2 45·3 1.0 17.2 43.8

(Trees miaa~d) I (4.3) ( 1.2) ( .1) (0) (0) (5· 7) - (0) (5. 7) -7 • 'l'O'l'AL 13.2 7.8 5·7 5·l ].8 35.8 100 3.5 39.3 100

Note - Add 2 and 4 for total ba1'k d•~e and ) and 4 tor total orown da.mage

NOT& - Figure a in braobts are those tree• r,ot aooowted tor, i.e. presumed fallen or broken in exploitation. ~_,y are inoludod ill the line ot data tor ••tallen or broken".

(ii) Control plot

TADLE 13. I.ouins Daap Oormeroial Speoiea - Girth (ft.) &: Di~~~er (om} Claaoee

Total ~ Catego1oy 1-2 2-3 3-4 4-5 5-6 1-6 1-6 6+ Total % 10-19 19-29 29-39 39-49 49-58 10-58 10-58 58+

1 • No damage 1.6 1.7 1.6 1.1 .6 6.7 15·5 .2 6.9 15.1 2. Bark damage only • 1 - - - • 1 .2 ·5 - .2 ·4 3. CroMn damage only 1.5 1.0 1 .1 1.2 1.2 6.1 14.2 ·5 6.5 14.2 4• C & B damage .4 ·9 1.1 .6 .6 3.6 8.4 .2 3.8 8.3 5· Standing tree~ 3.5 3·5 3.8 3.0 2.6 16.5 38.3 1.0 17 ·5 )8.2 6. F\P.llen or broke,;• 14.0 7.2 2.1 1.6 1.7 26.6 61.7 1.7 28.3 61.8

( Tx-eea mioued) (7 .8) ( 1.6) ( .1) (o) (. 1) - - ( .1) (9.8) -7. Wl'.AL 17.5 10.7 5·9 4.6 4.3 43.1 100 2.7 45.8 100

Note - Add 2 and 4 for total bark d&U8tt and 3 and 4 t'or total orotm d&Ege

NOT& - Figure a in braokete are those tree• not acoomted for, i.e. preeWIId fallen or broken in e.zploitatiou. They a"' included in the line of data tor "fallen or broken••.

Those •·re re-pres.nted belnw, in Table 14, on an overall baais but to show tne aotual brealcdoWl ot' daage, oinoe •c• of thie oan be rega1U..d as ot' no oonaequence. Unfortunately only tho dtt.ta of Nicholson wer. able to be recalculated to give 'ths p.\oture or the tree• belo~ 6' girth, the ou.rnmt cutting liJD.it. 'I'heae al'e uho.a1 in th~ first two oolUI!'Ile. The remaining six colUIIl• will have aoae small inoonaisteuoies du. to the different cutt in& liiDita ill 1957 L'ld 1966.

- 19-

TABLE 14. Overall Duye Nicholaon ( 1958a) Pox( ~968}

1-6 Girth All Tz•ea TI'e&ted Control

r]~·· " '7'88 ~ ~~es I

~ ~ee ha. ha. a. a.

1. .Pallen or broken 16.3 32.0 17.3 29·8 17.2 43·7 28.) 2. Bark damage and no or

inconhquential orotm damage 4·4* 8.6• 5·4* 9·3* 3.3* 8.;• 3.~

3. OonHquential crow da..age only 1.6 3.1 1.9 3·l 1.1 2.8 1.5

4• Bark daap and oonae-q\aellt ial o rown d&Mge ·1* 1.4• o.a• 1.4* 1.0* 2.5* 1.1*

5• TOTAL WITH CONSEQUS:lTIAL DAIWJE 2).0 45.2 25.4 43·7 22.6 57·5 33-9

6. Remaining tn.e• with in-oonaequential crow d••ge

4.2~ 10.7~ 5 .. 1~ ~a~ good tol"'':: + ).0 5·9 ) .. 3 5·7 b poor fona + 1.1 2.2 1.9 ).3

1. Undamaged 12.5~ 31.8~ 6.9~ ~a) good tom 18.0 35·4 20.2 34.8

b) poor to1111 s.a 11.4 7.3 12.6 8. 'roTA.L WITH IHCONSB~UL

OR NO DAMAGE 27.9 54.6 )2.7 56.) 16.7 42·5 12.0

9· ORAND TOl'AL 50·9 100 58.1 100 39.3 100 45.8

* Add these f~!:-.-e in each oolwm to get total bark damage, all considered of ooneeq~n.,e.

%

61.7

6.5*

).2

2.4*

73-9

11 .. o~

15.1) )

26.1

100

"'l- llot originally divided, but doue eo nov in the 8&IDO ratio aa the uncl.amged trees. Poaaibly a similar divi8ion could be made in Fbx'a data. -------------------------------------

Other data given by the above authors v•re tor the coa.roial etanda logged anCl "'81'81

Table B.A. Vol!lJ!U!la No./h~ -1 1 6.8 116.5 11.6 12 1 1. 7 222.4 15.) 13 12.6 239·3 16.6

'rheue vol'UIIes extracted, eapeoiall,y the latter two, are far higher than average ertn1.0tione even in 1977 or in tbe boom yeare of 1973 and 1976. Than. io then a reaeoa&ble explanation tor the poor n.•idual atands reported in 1968 and give j\lJlti­tioation for ua.illg the•• rather old data in yield foreoaata.

Within each experil-.nt, individual replioatea ahoved a fairly sood poaitive oo~lation between du.-ge and baa&l area or volume out •

.tt oan be seen that in 1957 (Nioholsorl 1958a in '!'able 14) tractor logging with no controls apart fro• the girth liaita, reaulted in 47 .4~ (34.~ + 12.6~) ot the residual stand being oo11pletely UD~t in this atand this waa 27.5 treea/ha. At the t i•, 7. 3 of these t ree• wre thou,sht to be or poor form. Apparently any evidence or ... 11 defects disqualified a tree and it ie now thcugbt that thiu division is not realiatio, and vill, in any oaae, vary froa atand to stand. It vaa not used by Pbx.

- 20-

Diares&niin& them here the m~ tree• below 6' girth anu

~ acceptable Ho./ha a.ooeptable

All Reaidualr.

Another eet of data from 7.8 ba ot tor.at lOftB".J in 1962 in the 8&- area g&'Ve the following (Table 15) residual stand a.tter ginl.ling all d.eteotivea by ominar,y aanap111nt atatr, i.e. not nt .... zoh groupe (Anon. 1962, page 12}.

f!'AllLE 15. Residual Stand•

Siq Claaa ~ ~!~ 1-2 2-3 3-4 4-5 5-6 'l'otal 10...19 19-29 29-39 39-42 42-~ 10...28

Ho./ba 4·5 5·4 4.0 2.7 l.1 20.3

'lbeee figures are very aim lar to the 1958(a) data above ('!'able 11).

Anon. (1963, page 22) giVed the following ti~a tor tr.ea remaining with none or aooeptable da~e after leggins (Table 16). 'Diey oo• from a oo111pletely ditterent looality in Sabah (Tawau) and are baaed ill 24·3 ha logged iD 1962.

TABLI 16. Rea idua.l Stands

Size Clasa ~ rt) 1-2 2-3 3-4 4-5 5-6 Total c•) 10..19 19-29 29-39 39-49 49-56 10:58

'f, undamaged or aligbtly da .. «ed 41.1 50.1 38.5 35 .. 6 44.2 42.1

No ./ha unde.tra.ged 6.8 or •lightly daa. ).6 2.2 1.5 , .8 15·9

'lbe JDe&n basal area •xtrsoted vao 7 ·5 a2/ha..

By 1967 (Fox 1968 in Table 14) daaage had apparently inon.aaed in the 5and.akan area and only 26 and 4~ re~a&ined u aooeptablo trees. He etatea that the level• of dau.gs have ino~aaed over ti• and not .. rely duet to inoreucd basal areaa b•ing extracted. This is probably true and should give foreet -.nasere gr.at conoem. It vaa aeen to be h&ppenins by otbeN (Anon. 1963, H1oholeon 1965, Chai 1975 eto ... ). However, that it 1• partly a ooD8eqUeDOe ot the heavier logging ia indicated by the t'aot that when tbe 1968 d&t&t. is euperi11p0 .. d on the r.greaaion linea given U1 Hioholaon 195& there ia & oloae a&reellent for total OOII&equenti&l d••q,ge, With the tr.ated plot shoving up v•r,y well with lover daaage (Table 17). (The taot that tbeae linea cannot be utended too tar muat be re•.m.~d. They muaii OW"Ve aa an e.xtr&ot•d B.£. of: 20 •2/u ia approached.)

- 21 -

TABLE 17. Comeriem of Lo&ains: Damage regreeeione)

(1968 ~ta from Table 14 with the 1958

Broke;, or Fall'iin ~ 1958 .Aetual

Re Be reeeiou l~

Treated 66.0 57·5 42.9 43.7 ~3.1 13.8

Contt'Ol 69.6 73.9 45.0 G1.7 24.6 12.1

•an 67.8 65.7 44.0 52.7 23.9 1).0

The diviaion of thie damage 110re to "broken or fallen" and lese to "bark/crown" damage is however a eerious ooneequanoe ot time. It should be noted however that though Pox oonoluded that there vaa a good poeitive correlation between damage and amount extracted, his regressions are ooneiderably different from those used above and it oan only be oonoluded that they oontain total crown damage and not only the part thought to be of ooneequenoe, and being baaed on a total of 16.2 ha and amll replicates (each 1.6 h&) correlation• will not be ao goad. However, his 1972 dis­cussion (Fox 1972, PAt~ 205) indicates that the correlation between basal area ext raoted and total damage baa nov been loet and that very heayy percentage damage ( 75-1~) oan be expeoted when B.A. extracted rise• above 12 m2/ha. It is believed that this arust be a ooneequanoe ot poor oontrol ov•r the logging operations and oarelese handling of lPtrp -.ohinery.

Further damage etudiee in 1977 1n the Tawau area were -.de on five, 4 ha plots (Chai 1978). Theee have not been tully worked up but acoeaa to tho raw data allowed some analya ie to be •de trom plot 1. (The full data. will be published in the Sa.bah Beee&roh Report ee1•iee.)

~ABLE 18. Data from Plot 1

Size Cl&alleB Total

Category 1-2 2-3 3-4 4-5 5-6 1-6 1 ~-;8 Total* 'Pt 1Q-19 19-29 29-39 39-49 49-58 10....58

No da-.ge 4.4 4·9 2.2 2.5 1. 5 15 ·5 23.4 17.2 24.0 Killed 18.8 10.4 5·9 2.2 3.0 40.3 69.8 41.8 58.3 Damapd 3.2 2~7 1.7 1.7 1.2 10.5 15.8 12.7 17.7

26.4 18.0 9·8 6.4 5·1 66.3 100 71.7 100

•Inoludee all oo~D~Deroial trees over 58 oa, aa well aa those between 10 and 58 om.

The number of trees felled in plot 1 waa 19 trees/h&. Plots 2-5 wen~ not tully analyeed in the tilfta available but that they were lees damaged ia olea.r t'l'Om the total tiguree which tor all plots are:

'!'ABLE 19,. Damye by Plot Totals

l{;, dam&&e Killed Da d

'ro'l'AL lio. of trees en ra.oted/ha

Plot 1 No a

17.2 41.8 12.

24 58 18

71.7 100

19.0

27.4 21.0

.2

52.6

9.1

52 40

8

100

20.7 40 )4.8 52 46.2 45 26.2 51 28.7 43 47-7 4.1

.2 8.6 8

51.3 100 66.7 100 102.5 100

12.8 11.9 16.1

4.2

- 22-

Though there io oonside1-a~le variation, the mean tf, total undamaged figure is 42.6% ldlioh is almont identical to that gi,ten tor trees br-low 58 om in Table 16 for a 1962 logging area near Tawau. ( :tnese inoluied some duaage whereas the 1977 data do not.) '!be fact that here there appaal"U to be no increase in daas&ge with the WJe of heavier machinery between 1962 and 1977 ia an indioo.tion that this ia not inevitable, even though it could be arglled that the earlier figure of 4~ unda~~agad ia too low. What i.e im~rtant ia that ttven in the poorest plot there Bl'e still 17 trees/ha (15.5 betwe~n 10 and 58 om) available for a fut~ orop.

Some of these data will be uaod ~1 section 6.2.1 as a basis ror yield projeo­tiona.

Since thia method of logging is not so common in Sabah there are less data on its effects. Nicholson ( 1965) saye "High lead logging has been fo\ZZld to be lese destru.otive overall, due probably to the fewer traotor traoks, and need cause leas ooncem than tre.otor logKing". This statement could perhaps be disputed with present day evidence when one considers thft value of advanced regeneration well on the vay to aorohantable Bizes (see section 4.3.2). However, it was baaed on aampling vork done in 1962 (Nicholson 1963&), below various ap&r tree• and shovs that a mean or 1836 mi llie.ore quad.x'ELta are atooked with commercial plants from seedlin88 upwaros. This is oone:i.dere.bly higher than most traotor logged areas. Similarly a DNDh am&ller sample taken both before and afte1• logging on the same lines ohowed a reduotion from 2000 to 1 )00 atoo~d plota/ha and some of these sample lines happened to follow long stretches of drngline and ba.ulbaok devaotated at-eaa, whioh would tend to reduce the stocking.

The same study showed that a very high proportion of the otooking was in seedling sizes. For example the 1836 stocked plots above are distributed ao follows:

Under 1.5-31l ht jm ht-5om

5-10om DBH 10om+ DBH :.Hze 1.5r:D ht DBH

No/ha 1700 118 12.4 1.0 4.4

West Jblayaia

4.2.1 Ground Loggi.ng Methods "

Not a great deal has been writton about actual logging damage in Wost JBlayaia. This io no doubt due t~ the cloo~r control that axiated during tha Shelterwood era e.Jld the lighter logg1;1g . ..,llioh gave no oon~en1. Wyatt-Smith and Foenander (1962) appear to have beon tho t'J..rot to write on it. For a heavily logged a~a. of rioh Kapur fol'eat they found that:

~ of the area \fa.a covered by e.x:traotion 11 l"'ado" 2~ of the ~rna.inder was ooval"ad by felled orowna 2$ of the aeoond remainder we a covered by boles.

Theae x~duce to~' 25.5% and 1.3% reopeotively, or a total of 35.~ of the whole area. 'l'hoy do not give a basal area or volwr.o extracted but it appears that at least 21.3 treeu/ha over 6' girth were extre.oted, ~:!&king it a heavy out by any atandaro.a. This being oo, tne low figure for axtraotion roads ia noteworthy and above what can be done.

-23-

'Hleir data for tree damage has been rearranged as :follows:

TABLE 20.

s

Tre Tre

Tre Tre

peoies Groups A&B

ea remining es lost

AL

C&D

ee remaining ee loet

~

1-2 10-19

29·4 13.8

43.2

31.4 13.8

45·2

Size o laso (:ft. _girth and om. dia~neterJ 2-3 3-4 4-5 5-6

19-29 29-39 39-49 49-58

8.2 7.2 4·0 2.0 3.5 0 0 1.,

11.6 7.2 4.0* 3·5

16.1 4.2 2.5 1.2 4.2 2.0 0 0

20.3 6.2 2.5* 1.2*

Total ! % 1Q-58

50.7 73 18.8 27

69-4 100

55·4 73 20.0 27

75·4 100

* l}beJ."8 was a net inoreaae after logging in these oolUDI1e. It is assumed no trees were lost.

Note: Speoies Groupe A - D are silvioultural groupe as follows:

A. Heavy hardwoods B. Medium alld lisht ha.rdwooda - preferred species C. Ditto - desirable species D. Ditto - .a.oceptable apeoies (Anon. 1963a, page III 5/935}.

The et riking ttdng about these data is the good nu.ber of advance growth remaining after logging, i.e. 50.7 treeo/ha of groupe A & B W!ioh would be mainly Dipterocarpe and in thio oase mainly Kapur. Preauma.bly, though, some of theoe treeo will have euftored bark and Ol'OW d....age so the picture may not be quite ao good. Even though only 21.4 trefts/ha a~ over 2' girth (19om dia.eter) it is obvioue that in this stand th9 arlvanoe growth alone will fully reatook tbe area vithout help from the seedling population. Kapur forest is, however, "abnormal" (Anon. 1963a, page III 7/10) and o&rriee a much more gregarious stand with a better oize olaoe distri­bution than muoh of the Weat Jtalayaian Dipterooarp forest.

Jlore recently new data are being oolleoted from typical bill forest areas. Tn particular by a large company Syarikat Jengka in Pahang and by FAO personnel. Their data are reproduoed in Table 21. Data seta (o.) to (f) are fc)r Skidder logging and eaoh represents a number of landinga or "se•-ups". For example (a) comas from 17 set-upa and (b) from 22. Acknowledgement ia ~e to the company for the use of theue data. The FAO data oomes from FAO 1976 page 87 and applied to 9 oet-upa of vinoh lorry opera~ ions.

-24-

TABLE 21. ResiduaJ. Stands - Jen@

Trees Cut{ha Trees/ha IBrked Residual fo Data Seta for Retention

(56 Ofltfo (15-56 u•). 'rrees/ha

(a 13.7 53.8 33.9 63 lb 8.4 26.5 15·4 58 (C 12.3 39·7 24.6 62 ~d 10.8 49·5 28.9 58 l 9 9·6 31.7 17.3 57

fJ 9·9 31.6 18.9 60

Means 10.8 38.8 23.2 60 FAO 13.0 46.0 29·9 65

The company data indicate that in the aile range of 15-56 om diaaeter, about 4~ of arked trees are damaged or lost in logging. In these oaaea it is believed that all commercial treea were included in the IIB.rking tor retention and not juat a oeri&i'n peroentage as in the Philippines (pana. 2.4}. The FAO data came tl'OII a slightly richsr area but uow a better rate ot retention. Volumes extraoted in these areas are not known, except that 41.6 r.3/ha were logged frons set (b). It ia likely, from tree numbe:re, th&t other seta would have carried higher volumes.

Other data given by Canonizado ( 1977) fl'OID the same &rea ia divided into size classes, and is given in Table 22.

TABLE 22. FUrther Data from Syarilcat Jene;ka, showing No/l!a

(a) ComR!Ol working (b) Contract workinS Diameter Claaaea (em) Diameter Claaaea (om)

15_-.30 JQ-4~ I 46-'56 I Total 15-30 30..46 46-'56 Total

DipterocaTI:J_e

Virgin 5-04 3.46 1.28 9.78 7. 73 7.34 3.53 18 .. 60 Residual 2.99 2.30 1.06 6.35 5·19 4-52 2.57 12.28 '/> IDea 41 34 17 35 33 38 27 34

Me rohe.n table rlon Dipterocarps

Virgin 4·45 3.06 1.04 8.55 11.00 5·96 2.64 19.60 Residual 2.55 2.05 .86 5-46 7-39 4.30 1.83 13.52

I

~ toea 43 33 17 36 33 28 31 31

llon Merchantable Trees

Virgin 9-34 ).88 .89 14.11 I 29.31 11.61 2.92 43.84 Residual 5.68 2-45 .62 8.75 I 18.43 7.31 1.78 zt.52 'fo Loa• 39 37 30 38

I 37 37 39 37 I

Juat why the stand both before and after logging for Canonizado 'a Company data ia ao poor ia not know but all these other recent data do point to a good reaidu.&l ata.nd. However, there are a nwaber ot areaa of concern. Firetly the rather high proportion of Hon~ipterooarpa in the reeidual atand, about half. It ia believed that, in the •in, theae apeoies are not or high value and .my are being accepted becaue of buoyant tilllbar •rketa. lbre aerious is the faot that little is kno.m ot their ailvicultu.re, particularly rate of growth. At beat they are only a oeoo.nd ohoioa. 'J.'Ihen again, field inspection• lhoved that many damaged or \81..he&lthy ••11 oroMned tree& were being aaoepted u reaidu.&la, despite report• to the OODtr&ry ( PAO 197 6 page 86) •

- 25-

4.2.2 Cable logging

Hish-lead logging baa a ver,y abort histor.r in Weet l&laysia being restricted to the Syarikat Jengka area. Data fmm 51 ha given in FAO 1976 page 67 sre the only data found are are:

Trees out/ha (56 o~tt) Residual Trees,/ha

60

'lbe stand appears to have been as ri.oh as the PAO data in Table 21 and very aillilar 1 .. aidual stand ia left. The sarae reservations ~bout the value of these rather high residual counts probably appl,y here too, as reoent inspections indios.ted.

4.3 ~iliREinea

4.3.1 High Lead Lcging

4.3.1.1 Etfeots on Land Surtaoe

Marcelo and 'l'agular ( 1956) •pped two spar tree settings and found 24~ and 26% of the area oo~~pletely destroyed. Nicholson ( 1970 and accompanying diary reports) made eatimtea in 1968/69 that re.nged usually from as low as 15% to about 35~, with one operation showing at least 5~ of the aet up completely bared of all reaiduala Gnd moat or the aeedlinss vould have been re~r.oved trom a aiiDilar area. He notes that this waa probably the woret example of high lead logging aeon anywhere in thet Philippines. The present day position r.bowa much the sam variability ao Caoanil1din et al ( 1976) report a mean of 31~ bf.red, ranging from 17 to 46~ in the thirteen aet-upe they st\died.

Thia variation indicates ·that it io possible to uae high lead and s)cyline logging methode with aooept&ble levels of damage. In faot Brigham { 1971) shows by actual demcmotration of supervised logging that it is poaoible to redUDo the Al"'&S

with poor residual stands to 1()'/, of the total area.

4.3.1.2 Seedling D&!!ft!

A lot haa been written {from Brown and JBthewa 1919 on warda in Sel'\lvo 1949, r·nd Heyaa 1959) about the destruction of oeadlingo from exoeooive insolation following logging but few actual data oan be towd. Sudden axpoaure may kill a large percent­age or Dipterooarp oeedlingo (eepeoially in hot dry periodo; see pam. 1. 1) but e auft'ioient number uaU&lly euxvive (and After a ohort time grow very rapidly) and it is believed that ru.n,y ot tho reports give a vorse picture than l-,;,ality.

Revilla ( 1976) shows that 25 000 to 100 000 seedlings nay be preaont in tho pre logged condition, and observations uaually confirmed these high numbers. ThUll a very high losa in and following loging oan be tolerated and still leave an adequate atooking. Thi• ia oonfix.d by figureo quoted by Hayeo ( 1959) and the varioua oboervations in the following disousaion.

Some u.uetul information vas collected at lpil by company pereonnal. Here a very heavily logged and opened up hillside vaa sampled by nUI!IeroUB s-.11 but permanently marked plot a. The hillside oeriainly looked a ••write-oftt' as regardo Dipterooarpe until one ata.rted looking in the 1-2 metre high re&l'Ovth. 1ll faot, the plote shoved 3300 per ha and BollS t~ere growing w•ll.

- 26 -

This and other of ~ observations in the Philippines &gTee with those made in Sabah, in that enough seedling regeneration is usually present after logging to tully restock the area. Not muoh data were actually collected but on three high lead areas, stocking of Philippine mahogany speoiea was:

Ho. of Y 400th ha plots stooked/ha

Size Baailan Agw!an Negros Oriental -tmde r 3m high 100 120 200 3m high to 10om d. 140 140 100 OVer 10om d. 130 60 20

370 320 320

Theeo data were not collected to show specifically the amount of seedling regen­eration, and larger plants were always taken when p.~.~sent. It is probable then that moat if not all of the plots stooked with the larger sizes vould contain seedlings aa vall.

Many other observations showed the adequate presence or Dipterooarp seedlings. For ezample, in an area at Fabrioa logged solD& six years previously and pointed out as an example of useless regrowth (lbllotua) to about 6 m high, an inspection showed the adequate presenoa of Diptarocarp regeneration aoM.ttered through it. They were up to about 6 em diameter and nearly aa tall aa the lhllotus and of exo9llent rom. Similarly a random inspoction or an area logged ten years previously at Bislig, and which looked from the exterior to be only a maso of vines and uaeleaa regrovtb, showed & very good stocking of young red luan to about 15 om diameter and of good form. In both areas, they must have ~ ... an there aa seedlings at the tiDie of logging and the areas must have looked like the Ipil area mentioned above. In raot, on only one area seen immediately after logging was the seedling population thought to be inadequate. Other stands originating from seedling populations ware seen in many areas and some of theoe were really eXcellent (Antipolo, ~apaeok etc.).

4.3.1.3 Damage to Advance Growth

Here there is a great deal of data oollected by the Bureau of Fbreat Development in the after logging stands but not available in any published form. The best a\llllDW.ry ia probably that of Endacott (1977) and io given in Tablu 23.

TABLE 23. Sununary of lleilidual Stands

Size Class Mindanao Vieayas Luzon om diam. no./ha no./ha no/ha

15-25 ( 20.0) 21.3 ( 20.0) 25-35 10.4 16.1 10.7 35-45 9.3 11.7 1·4 45-55 7.3 6.2 5·9 55-65 5.1 4·5 3.1 65-75 2.9 1.6 1.5 lfotal 55·0 63.4 48.6

He notes (page 32) that it is probable that many trees included above do not come up to "Residual" standards vi th regard to health and defect, oo that the above fi~o are probably too high or at least represent the better residual stands. This probability ia in &gl,.el88nt with ray own observation• a11d with mat of the Co•pany Reeidual Inventori.ea that I have seen. For u:ampla, the following data (,.ble 24) are the ave~e or twenty separate inventories from the whole ruge ot oliaatio types

- 27-

in the Philippines. (Preswaably some tractor logging is inoluded in these and thEt above figures.)

TABLE 24. Co\lltry Wide Rasidual Stand

Ho./ha 7.8 25-35 I 35-45 l 45-551 65-15 I

2.0

Total I 26.6

Si£e Class 1

Another reaa·on for the higher figures could be the siting of inventory plots only on good are&i'i. This praot ice has been stopped (Reyes, Pere. Com.rn.) but would have applied to ma~y of the plots summarized by Endaoott. This is confirmed by Canonizado (1976, ~~e 48).

Heoently Weidel·~ ( 1976) working in Eaetem Mindanao provided the baeio data for Tables 25 and 26. Thll figures are tor healthy Dipterooarps only, exoept as noted.

TABLE 25. Set . up No • ,. - 10 ha

+ H>-58 0111

+ Total

No. remaining 8.9 1·9 5·7 2.9 3.3 2.1 ·5 31.4 31 43 No. destroyed or dama.ged 12.7 10.0 5·9 4.8 2.7 3.6 39·7 41 'i7

No. loggod 24.6 24.6 'l'OTAL 21.6 17.9 11.6 1·1 6.0 5·1 25.1 95·6 72 100

*Inoludea 1.2 treea/ha of Nato and 0.2 of Kalantas

'!'ABLE 26. Set up llo. 2* - 22.2 ha

No. remaining 8.0 1·5 4.8 2.3 1.8 1.5 26.2 21 33 No. destroyed or damaged 18., 13.9 8.2 5·1 3.3 2.8 51.~ 56 67

No. logged 19.8 19.8 TOTAL 26~ 1 21.4 13.0 7.4 5· 1 4·3 19.8 91.1 83 100

• Includes 5·3 treeo/ha of Nato

(NOTE - The last oolumno have been added by extrapolation for oompariaon with S&bah figures.)

The top line of eaoh table would be the no1"mal figu.r.,u reported in "Residual inventories", and it oan be seen to be very oloB4.'l to my company figures quoted above (Table 24). It ia not known just how nauoh da.-ge ia accepted in the "Ho. l."e•ining'' category, preou.mably very little and ao they ahould oompare with the "no dt.unage" linea of Tables 11, 12 and 13. It oan be seen that 43~ and 33~ remaining here oompare vith 4'71-, 31~ and 16~ repor-ted above for tractor lo&~ed areas in Sabah {or 55~, 421> and 26~ if non-oonaequential damage ia included in tha S&bah figures, Table 14).

These two set-ups {Tables 25 and 26} were very different topog~phically, the firet b~ing level and the aeoond in ~~ader&te to l'Ough toil()gre.pby and thia mu&t influence the degree of damage. Then ~in utra care wa..' taken in the fit•at and not in the second. Thus they are not atriotly oompa~ble with themselves or the Sabah data but aa spot euaplea they show similar orders of damage.

4.3 .2 Tractor D~age

.. n - ~0 -

Little actual comparative data has been aeen. Observations (Nicholson 1970) and the general consensus of opinion ia that trsotor working io lees injurioua to the residuals. Brigham ( 1971) agrees with this but f"avours high lead logging on economic and environmental grounds.

Weidelt (1976) shows the lesser injur,y to reaidualo with some actual data, aa below, tor healthy Dipterooarp residuals only, ezcept f"or 1.4 trees of" llato/ha.

TABLE 27. Set up No. ) - ].6 ha

Total

No. remining 14.6 14.4 10.7 5·9 4·7 4·4 1.4 56.1 55 62 No. deetroyed or damaged 11.6 10.4 3.0 2.2 1.5 3.0 31.7 33 38 No. logged 20.5 20.5 TOTAL 26.2 24.6 13.7 8.1 6.2 1·4 21.9 108.) 88 100

(NOTE - The last colwma added for ooapariaona aa before)

It is clear, atLd as pointed out by Weidelt, that there is a better retention of advance growth with tractor logging even thou,sh this set-up was logged with oa.%'8 and should represent an optir.lWD rather than an average. Comparing the data from Tables 25, 26 and 27, and converting to percentage• we have:

High Lead (Table 25) High lead (Table 26) Tractor (Table 27)

~ Retention of Total No.jba Incl\Uing tree• lossed Without treee logged

33 27 52

44 34 64

He notes alao that the last area was logged more lightly; the aotua.l volumes ramoved were 244 ml/ha, 222 m3jba and 187 rrJjba respectively and this also h&*J a 1&1•ge influence on the amounts of daa&&e.

Aa mentioned above juat how much damage was accepted· in healthy residuals io not knolCI'l but the peroento.ge retention is certainly better than in Sabah and IINSt be a pointer to the ef'tio&ay of carefUl tractor yarding even with the~e high extraotion volumes. A Jl<.'int or l'elevanoe here ie that tt~tor yarding can appear to leave a good residual stand because it destroys fewer trees, but careless u.ae can inflict severe bark and wood wounds which will probably render the trees useleae or greatJ..y increase the defeat. 'I'hia applies also to hi&b l .. ad yaming but here more treee actually are destroyed.

The Bureau of Forest Develo~t lays dowrl limits for acceptable d•mage. These are oon•iderably more tolerant of bark davge than those uaed in Sabah. Timber Injury Stulios as were 'begwJ. in 1969 (NioholiiOil 1970) have not been pureued, but are vitally neoeaa&ry to solve this tree daNge question. In the meantille ttatt Residual Inventory should reoord the sort of d•Mge inflicted and not only tha-c. a tree oan b• regarded as heal thy or not, aa at present.

- 29 -

4.4 Sarawak

4c4•1 Effects of Tractor Logging on Land Surface

F1guxea given by Hutchinson (1977, paraa. 4.6.3.2 and 4.6.3.3) show that 22% and 1 2t, are c laaaed as 11 TaiiJ)Orary open apace" and "Bs .• .-.. so i 1 exposed b:; logging", a.fter logging. The latter category is directly comparable with "Traotor paths" (snig tracks) and "landings19 as discussed for the o·ther countries of the region. The temporary open apaoa by definition ia devoid of trees but as it doe• have tcp soil, very often it will carry a atooking of Dipterooarp seedlings. These dsta were taken from an area on which 7.2 treee/ha were out. ThUB it appears that ourr.ant exploitation and resulting damage are still within aooepnable limits in Sarawak. Hutchinson takes a cautious attitude in disous~ing heavier logging inte.'l&itieo and foresees a situation similar to that after clear cutting and neoesoitating ragene1'8-tion from seedlings (page 174}. This logging rate is, however, still low when com­pared to figures from Sabab of 11.6, 15.3 and 16.6 (para. 4.1.1.3 above) and fro~ the Philippines of 19.8 and 24.6 (para. 4.3.1.3 above) and. t~here there is still a reae~· onable residual stand on vhioh to plan a second out.

4.4.2 DaJn¥e to Advance Growth from Tractor Logging

Hutchinson ( 1977) a.gf.in provides tho moa+. recent data. The following da'ca in Table 28 have bean ext rN:ted from hie table 4.12.3 psga ~77 and converted to '-.rees/ha. It includes only his wood quality groupe I a:1d II, i.e. currently oo~~~~eroia.1 apeoiea ..

TABLE 28. Aftt.r Logging Stand Table for Sarawak by Damase and Sise Clasaes

Category

No d&~Da~.se 10.7 3·4 4.0 Stem in,)ury 2.2 1.0 1.0 Crown injury 1.6 1.6 ·4 Both types 1.4 ·4 Standing treas 15.9 6.4 5·4 Broken .a .8 .. 6 Mi.osing t reeo• 2.8 ·5 TOTAL 19.4 7.6 5·9

*Calculated. fl"'m Hutchinson's faotore on page 170.

22.4 ss.s 5·0 1.).0 ).8 9·9 i.8 4·1

33.0 86.2 2.2 5·7 ).3 8.6

38.3 100

6+ 8+ Total

5.1 2.0 .6 .6

8.3

8.3

27 ·5 6.9 4.3 2.4

41.1 2.2 3.3

46.6

Other very similar data are given in his Guidelines Table 4.4.1, which also gives 38.7 and 6611 trees/h& ror the 10-19 and under 10om olao3as reapectivaly for reoent ly logged fo~at • whiob figures extend the "standing treeatt linu of Table 28 back to smaller sizes.

It oan be seen that damage is l~sa than in the dO.tii ~Jf Hioholaon an:1 Fox (Tab lea 11, 12 Blld 13) given above f\or Sabab but oomparabl~ to some given by Cha.i (Table 19). Here 116&in the logging l'&te vas 7.2 treea/ha.

4.5 Indonesia

4.5.1 Seedling Damase

Saatroaumarto ( 1978) quotes data a11 MGdling atoolcing both befor•:. and attar logging from Soelcot jo et al ( 1975). They wore taken from ni_;ae oonoeaeion areas in &&at Kali~Mntan. 'nle data are not &ntin.l,y nomparr.ble with the data from Sabah (pare.. 4.1.1.2 and 4.1.2) and tht- Phi ~~(1pinea (para. 4.3.1.2) because the logged areas

- 30-

were sampled aom.l! 2 and 4··5 yeare atter logging. All data lf&8 collected by rnilliaore sampling (see footnote in ~ra.. 4.1.1.2) and preaented aa ~ stocking. For the purpose of thia paper all the concession al"C!&a h&ve been ocmbined (but the range of values encounted is given) and tho equivalent miniiiiWD stocking per hectare has been added to show the numbers of treea involved.

'!'ABLE 29. Milliaore Seed lin.(. Stocking - Indonesia

·~~rtable 5£!Ciea % Stocking & Rane JUnillftlm No/ha & Ran!!,

Virgin 66 ~2~·92~ 1650 ~ 625-2)00l Logged 1970-71 49 24-69 1225 600-1725 Logged 1973 62 41-87 1550 (1025-2175

Other Co ... rcial Species % Stocking & Range Minimum NoJha & Ranre

Virgin 53 ~ 1-90l 1325 r5-2250) logged 1970-71 39 7-69 975 175-1725

1050 400..1725~ IA?P,l'ed 1973 42 16-69)

*'lbeae are not defined but are preaUIII&bly moatly Diptorooarpe (see para.. 3.5 &: ifaeruman 1978).

It is apparent from the above that the tvo olaaaea or coiUiroial apeoiea were sAmpled independently, ao it i~ not possible to arrive at the peroent~e stocking or all commercials. In the virgin condition, bowever, it must have been 1~ or nearA.:.' ao ( 6~ + 53~, with some oo\l'lto fmm the a&IDB quadrats). Confining the diocnmsion to exportable apeciefl, all e~ooking rates even after logging are seen ~o be adequate. The data in foot 9.l'e better than those from most areaa in Sabab (Table 10) and other ootalt riea in the region.

4.5.2 Darrecse to Advance growth

Saatroa\lJ'Itarto ( 1978) gives data on advance growth atooking and damage sustained, from the nine oonoeaaions diaousaed in par&. 4.5.1. Ha inoludea both exportable and other oom.mu'Oial apeoiea iJ1 the following date..

No/ha after logging

~ with non-fatal damage Derived no/ha with ~on-fatal

daMBe

No/ha d3atroyed Derived 'fo deatroyed No/ha before loggit;g

Sic(J olaea (em) 20..50 35;-50 5,0+

27 .1* (31.3)

29 7.8

(9 .1)

15.1 32'% 46.4

12.2

*Hls figure of 27.1 sppeare to be an error and should be 31.3 unless tbe individual oonoesaion da~a have b~en weighted for area - but tor the other size ~e the ~an ie ilot weighted. The figure• in bl'e.Oketo ·~ the oorreoted data ..

~• leas the 7.0 treea/ba logged. 'i'here were 23.7 over ')0 oabef'ore loggiu.g~

- 31 -

'Iheae data are on the 'Mhole better t~an those from Sabah but siailar to those from SaraM&k. 'Ibey show a good residual stand of o01111eroial trees of which 22.2,/ha should bs undamaged and it is worth noting that this ia close to the ti~ or 25 specified in the Indonesian Selection System, tho~ one haa to go to 20 om diamater to get them. (Sefl tables 14 and 19 for Sabahan figu.nts. Comparison can only be made through percentages as different Btandama for ooaaeroial tree• are involved. Note that logging ratee were higher in Sabah. The Sarawak data ie given ill Table 28) •

Tinal and Palenewen ( 1978) also give data from E. Kalimantan. They sampled 4 ha of logged forest using categories similar to thoa. of Nicholson { 1958). !hey conclude that there remin only 13 Dipterooarp trees/ha over 14 om diameter after logging; of those only 7 ·5 are free of significant crown or bark damage. Thoy state that rtJ.planting is necessary a.fter logging. Howevor, there 111 eome doubt about their figures sin~e their Table 1 gives 120 trees/ha without damage of which about 39 are likely to be Di~terooarpa (on species ratios they quote). CoJIIP(&re with the 7 ·5 treea/ha given above. Sinoe their figure for percentage broken or fallen is about 2~, the higher figure of 39 treea/ha is more likely to be oorreot, and is in rough agreement vith the data of Johnson and Dykst r& ( 1978).

1.Ihey alao present regraesions of damage on baaal area utraoted. It ia of interest that dam&fre (whether it be total, broken or b&rk/orolG'l damage} hardly inoreases with incroaaing logging intensity. The gradient for the "total damage" regression ia only .061. Whether this eu~porte Fbx'e (1972 page 205) contention that with modern heavy logging the correlation between volume eztraotad and d~~e i• lost, is not o~rtain. Aa ~be logging waa heavy (+ 20 treea/ha over 50 em) it could vall be.

Doubts aside, their data do indioate that greater care in logging ia required. It is probable too that more extensive data is needed to better dooument the damage story.

5. YIElD lt"OilOOASTS

Yield foreo~ota at best only can be indioationo of fut~ yieldo. ~en when applied to the oame BtMda an pmduoe(i the basic dat& there are so many Wlk:nown eventua.litiea tha-t oould occur that the final yield may be very different. When a}lplied to different nta.nds or ae ma.-..na, even g1'eater diaoreparaoiea oan ocoul". hven the ~~ethod of projection will greatly affeot thtt reet!lt. This being aaid, ao;.·v~ effort must nevertheleeo be made to aee vhat 8ffeota present management c..ctiono will have in the future. Thl!l'e are five basic seto of information we need bet'ol"a yield projcotioua can be aade. '!bey are:

1 'I!ut initial Stand Table 2 Rates of growth 3 lllrtality 4 Ht.o rui t maz1t 5 Area.

5.1 The Stand Table

Th:lu is perhaps the moat easily obt&intJd data. Hawever, even here there are dif­fioultiea such aa amounts of da~e or natu~l defeot that oan be tole~ted now on an effect­ive ater.:~ remembering that a long period will elapae befo~ it is out. Then, too, markets way change w1th time and use dit'fenmt upeoiea or require different produote. Jud&omanta have to be made on ouoh queationa on the basis of researoh fo1• the fol'TI\er type of quaotion or on intuitioo for the uoond type, though there ia no real likelihood that oellulone in all fill"DD8 will not find a ready ID&l'kat in the futuns.

- 32-

5.2 Rates of Growth

These vary with species, sj.ze, health, competition, time, BDils, climate, and treatment. It can be seen therefore that no simple figure can poesibly cover all stands and yet some simplification of this variable has to be used. Climate and soils usually can be oegregated easily; of the others, the first simpliti~tion is usually to group similar species am then use mean increments in size claases, e.g. feet girth or 10 centimetre diameter clasoes. The oth~ro will or will not be applied depeuding on the sophietication of data collection. In tropical forests, since most trees do not have Bnnual riJ188, the only was to collect such data is by tbe expensive am time-consuming process of repeated measurement of sample plots covering all the required variables. If for no other reason than the time involved, no country has the complete aneweN and inevitably extrapolations have to be mada. For example, the effects of the initial logging, and sometimes treatment, have to be projected using sometimes 11 relatively short time span early in the cycle to determine what is the rate of chaf!88, if any, of these effects. Future treatmenta and their effects aro difficult to p1~ject when there are no similar forests on which to baas experiments. However, some effort has been made in moat countries to obtain good data. The series of Yield Plots in Sabah (F,ox 1970) and the c.P.I. plots in the Philippines ( Tagudar 1961 1 Anon. 1965a) are examples.

Then the way of using increments to project tte eta.ni can g1oeatly influence the result. This will be discussed in section 5.6.

5.3 Mortality

Figures are usually obtained in the same plots in which incrementa are measured. They can be very variable and wi 11 often depend on what sort of trees are uaed tc. make up the initial ota.m.. For example, the death rate amoJ189t appa~~ntly healtey treea (in the aenne that they have large leafy crowns without logging damage) will be much less ·than unhealthy trees (see alec Tang 1977, page 98). I have not seen data on this point but I have obaerwd a long period of low or no growth before a tree is recorded ae dead, am. it is alw~s found (Fox 1972, in Whitmore 1975 ani Nicholson 1963, for example) that large crowntsd trees grow fastest. Therefore by reatrioting the initial stand to such treea a ver,y low death rate can be applied.

Similarly it is usually found that the ~te of mortality io higher in the lower ctiameter classes, no doubt due to the severe competition for apace (Fox 1972 page 158) &l'¥1 again it is usually high in danae young atat¥ls that ~ follow loge,'ing or treatment, but here it can ha,.,'t) •1o effect on yield since such stands are very overstocked.

The actual value of tho rate of mortality to apply in stand projections is therefore still u. ~tter for experiment. The figures used by various authors will be given in Section 6 when di acuseing each country. Here it can be said that I favour a figure of about 1% per yoar as an aver.age foi· all ai.zee. Sol'!\e of my own data (Nicholson ~963, page 70) show a IJlortality rate of 1.06~ per year amo"¥ 1200 trees in unlogged forest ovor a 6 yea.r period. The same figure is ufled by Weidelt (1976) and by Fox (1972 1 page 158) but in the latter case it is restricted to trees over 48 em diameter, smaller treos having a high6r rate. Hutchinson (1977, page 59) too, uses a higbor rate but it ia b&aed on a very llhort period of observation.

5.4 Recruitment

The rate of ingrowth of new growing atock: is important too, but becauoe of the nature of the logging and the response of Dipteroca.rps to it 1 it ia not usll&lly a gradual process as in virgin or nea1·ly virgin forests, but oocure rapidly a short time after logging and or treatment am thereafter the crop treea can be followed for increment and mortality. For the first cycle in a eeleotive logging regime recruitments will have little or nu effect on yield except tbrougb ita competitive effect on growth, since fev treea will reach

- :n -

merchantable sizes in that time. Umer either sort of logging regime (i.e. uniform or oelection) my own experience irnicates that recruitment in mixed Dipterocarp forests will not be a problem given only reasonable logging control. {See for eDJDple, Nicholson 1965 and par.a•s. 4.1.1.2 and 4.3.1.2 above).

Area -Thin is of overriding importance of course, but is sometimes not easy to obtain.

Firstly the area of a countr,r or region set aside for watershed protection, or that is deemed too stoep for logging. has to be estimated am criteria for datermining these a.re likely to change with time. Then too, it is only the logged portion of the foreet area (or otherwise opened up in treatmant) -that can be considered as having any increment since in unlogged forest growth is balanced by death (Nicholson 1963, Whitmore 1975). There is the important con~ideration too of the represen·tativeness of the plots used in obtaining a tam tables, increment a.nd mortality. As shown above ( 4.1 .1 .1 for example) , logged ~ores t has a consider.able a1-ea of bare soil, and unless ito area is accurataly known this area must be included in the plots used to sample the logged stand oharacteriotios. It will be included when a grid of systematic or randomly located plots is used, whoae individual positions are decided without roference to the fot~st. There is a nbtural tendency when laying out measurem~nt plots to l'!lOW off such bare or poor areas to well stocked areas. Aa ! pointed out ( liicbolaon 1970, page 31) this is a very unsound mow and causes a atroJ18 bias in the average stand table am possibly too in i11crement and morta.li ty (see a.leo Section 4.3.1.3). Endacott ( 1977, page 38) finds the same problem. The dif£iculty in using these figures is that usually the extent of such moves is not known. In practice therefore, all measurements and assessments in logged forest ahoald be on a groa~ area basis. In this way, itJlarvis of unlogged forest will also bo correctly included in tho data. ).6 Cha.racteriatioa e>f Tree Incx·emente

As intimated above tree increments are very variable. '!be use of trer.dc in mean increments often obscures this fact of var.iation often within the same species and size olaos, (Nicholson 1963, page 77). This was explained as a responaQ to different crown sizes which in turn is dependant on the amount of light received. This spread of incre~nt within a size class means that a number of trees grouped in it at one particular time will not stay together but \·lill apread themselves among the size classes and this aprea.d wi 11 become wider as the period between measures increases. The slower ones will remain in the claao for maf\Y years and perhaps diw there, while the faster ones will progreaa one or more cla~ses 1n, BC13f a. 10 year period.

However, as thia is occurring in every class the erd result (at least over a fa.i 1·ly ohort period) of projecting forward ao.ch irrlividual tree wi.ll a.pproltimate that obtained by using me!l.n figures. Errore are likely to occur when there ia e. steeply falling stand table. In these cases the uoe of the best increments equal in number to the trees in the next higher cla.oo should adjust for theoe errore, (Nicholson 1963, page 81). It is seen, however, tha.t after logging stand tables have fairly uniform numbers of trees 1n the h~gber aize3 and hence this error if it occurs will be only alight. In all stand table projections that I have o~en, the whole stand is used and projected either for a certain number of years or until a. certain volume can be harvested. The discussion just above shows that this will be unsound in many caaeo. It is believed that we should specify how many trees/ha will consti tu.te f'ull stocking a.nd then usc only this numbex- of the best incl'\'lmenta back tht>ougb the claasea. The method presupposes that we know what stand we want am this is the difflculty (see 6.2.2 below). Hutchinson ( 1977, page 226) usea an elaborate system, soon to be computerised, whereby the starn is classified into crown illumination classes, each with its relevant increment. At each intermediate ten year proJection period the trees a1~ reallocated among the classes. If the data baae for making the initial and subsequent allottments to the illumination claasea, and tho relevant gro~th ~tes for these classes, is in fact sufficient~ extezwive, then the syetem must be a refinement.

-34-

In the following prnjeotions tor ten year periods am using 10 om diameter classes, the range of increments within any size ol.aaa ill approximately allowed for, by putting the proportion of ita trees that aove out into the nen or higher claaees, equal to the mean increment for the class. For example, it the mean annual increment of the trees in a claiJs is .39 em, then in 10 years the mean of the original trees will have moved up 3.9 ems. As mentioned above, if the stand table ia not falling too steeply at this class, then about .39ths (3~) of the trees in the class will spill over into the ne~ clasP. Similarly if the increment is say 1 .13 oms then in ten years all the tree& are assumed to move out of the class am .13th ( 1)1,) of the trees into the next higher class. Hutchinson's ( 1977) growth index is derived by the same r-easoning, am follows Avery( 1967).

It is stressed, however, that the method is a relatively crude one arxl cannot give an accurate picture of a future stand table. This beco!DfJs clearer in the case of a single diameter olasn growing at 1 em/year. Here the trees in the claaa will in this theory all move into the next class, thus staying together. In fact they will spread just as for other increments. The only vay out ill to use individual incrementa and very narrow size claeaea and it then becomes necesB&ry to resort to computer facilities as used by Higgins (1977) and others.

6 • COUNTRY PROJECTIOW

6.1 Philippines

Endacott ( 1977, page 40) reports at length on the methods b~a used for yield projeo­tions to 30 years, in each of the tour regional zones. Very briefll' his atam tables were from the Bureau of Forest Development "' inven-tory. Similarly increment figures were derived from Continuous Fore11t Inventory (C.F.I.) plots. 'l'beee latter were not used for stand table data because of their subjective location in better stocked stands. Hio residual a tam tables and reapeoti ve incrementa are reported here for ~ reference ( oee a leo Table 23) • ( I have not worked vi th hio Palavan data since hti suapeota they may be inaccurate being baaed on a 11mall amount of data only. It ehould also be noted that tbeae regional dat• cut across the climatic types as commonly used - some data in Table 4. Just what is the eignificance of this is not known at present, but a grouping by climatic types would be expect~d to yield more conaietent results).

TABLE 31. Residual Stant Tables

Size Mirxlanao Via;ya• -Class Trees/ha Inc. Trees~ Inc.

5-15 ~ 51).0~ .39 < so.o) .31 15-25 20.0 .48 21.33 .37 25-35 10.42 ·57 16.06 .40 35-45 9.30 .66 11.71 .so 45-55 7.28 .75 8.15 .56 55-65 5.11 .as 4.50 .62 65-75 2.89 .93 1.56 .68 75-85 1.00 .73 85-95* 1.06* .78* 95-105* 1.1()1t .80* 105-115* 1.14* .82* 115-125* 1.16* -

* l(y extrapolations, eee below.

Luzon

Troeo/ba

( 5(>.0~ ( 20.0

10.68 7.41 5.92 3.10 1.51

Inc.

.28

.36

.43

.51

.58

.65 e71 • 75 • 79*

0* • a --

- 35-

These data are projected forward in 3, 10 year periods graphically. However he reganls all the trees of a claao a.s being origimlly at the class centre and they all either stay in a class or 9rogreaa upwards together depeniing on their time of passa.ge. He di video the smaller classes into a log atd pulp product. I have disregarded the latter as it is questionable whether such volume will ever be used in most areas.

His pt"Ojections give the 30 year a tarn as in Table 32. I have also totalled the volumes aoco~ing to current felling limits, i.e. 2~ of class 55-65 and 5~ of class 65-75 and 1~ ove1" 75 ems, to give a current figure of merchantable K.A.I.

TABLE 32 Residual Stanis Erl't~r 30 yf!lar Projectio:~s by Endacott

s· Minda Vi L lZ\l ~ sms uzon -Class Trees/M Vol/ha T~es/ha_ Vol/ha Trees/ha. Vol/hs.

5-15 12.2 - 12.2 - 12.2 -15-25 12.2 1.52 12.2. 1.51 12.2 1.43 25-35 - - 12.2 5.09 12.2 4.28 35-45 12.2 10.47 12.2 9.91 10.68 8.28 45-55 10~42 15.06 - - - -55-65 9.30 22.86 11.71 25.41 7.41 14.47 65-75 - - 8.15 28.54 5-92 16.92 75-85 7.28 37.49 4.50 21.37 3.10 12.86 85-95 5.11 36.28 1.56 10.30 1.51 8.84 95-105 2.89 27,46

Total 151.14 102.13 58.25 Kerch. Total 106.95 53.72 34.63 Meroh. Tot. at Yr~ 0 9.06 5.43 3.88 Kerch. Tot. MAI 3.26 1.61 1.03

It will be noticed that no mortality rate& have be~n applied. En{~cott derives a figure of 1~.2 trees/ha ao optimum stocking for 60 em trees h...:l for tre,Ja below this aize numbers in exoess of 12.2 are taken out as pulp. 'l'hie is not realia·tic considering the widely epaced hax-veats. However, ncne ot· the cl&aaes that contain more than 12.2 trees reaches log merob.ant&bility in 30 yeaN. In ert·ect he does not consider mortality for the firot cut of logs.

Using the methods outlined above (para. 5 ,6) my own pl,ojections of bis figures give the followif18 result (Table 33). They have been carried on to fo•ty years also. See worked example in Appendix 1. To do this somo oonaervati ve ertra.polation of his increment data was neoeaaary. For Mindanao they were levelled off at 1.16 ems/year at 120 ems diameter, for the Vt.sayaa at .82 ~ma a..\ 110 ems and for Luzon a.t .80 oms/year at 100 ems diameter. These figures have been added to Table 31 abowft

Weidelt ( 1976) usee a flat figure of 25% mortality for a i.hirty year period, or an annual rate of abcut 1~ (compound) and in the abAence of better figui'\ls th.ia rate was applied to ~ projections, even though it ~ var,y between smaller and larget• and between vigoroue aDd leea vigorous trees as mentioned in para. 5.3.

Recrui taaent does not affect this intermediate yield (para. 5.4) but it io se.fe to aa.y that given only minimal care, recruitment in the small r&umbere neAded to fully stock a selectively logged etarxl, will alwaya be sufficient and has been added in Appen:lix 1. It can be seen that volume production from this residual stand ia reasonable for Mindanao, low for the Vi~ am probably lese than merchantable for Luzon even at 40 years.

- 36 -

TABLE 33 My own Projections of Endacott•s Data (See Text)

Mindanao

ze Si Cla ss -

15 5-15-25-35-45-55-6 65-75-8 85-95-105-115

25 35 45 55

5* 75* 5

95 105

115 -125

30 yrs. TJha V/ha

37.0 27.9 18.8 11.4 6.9 5.3 3.3 4.6 9.4 3.9 20.1 3.1 22.0 1.9 18.1

.1 1.2 - --

• Meroh.V. Tot Vol Mere

74.1 • Yr.o 9.1 h. Vol.MAI 2.17

40 yrs. T/ha V}ha

33.5 26.1 19.4 13.2 8~3 5·4 3.3 4.4 9.0 3.9 20.1 3.5 24.9 2.6 24.7 1.7 21.1

.3 4.1

107.2 9.1

2.45

ViB!\Y,&S

30 yra. Tfha V/na 40 y/i

T/ha V ha

37.0 33.5 27.1 25.8 18.6 19.2 11.1 11.8 8.3 8.4 6.4 3.5 6.4 3.5 4.7 9.1 4·9 9·5 3.1 14.7 3.7 17.4 1.5 9.9 2.3 15.4

·5 4.4 1.2 10.:2 - - .4 4.6 - - - -

- -41.6 60.6 5·5 5·5

1.20 1. 38

* Volumes as per current loggiJ18 rules.

Lueon

,1;o yrs.

T h& V/h& 40 yra.

TJha V/ha

37.0 33.5 25.2 23.9 15.6 16.3 9.0 10.1 5·7 6.3 4.3 2.1 4.4 2.1 3.3 5.2 3.5 5.4 2.3 9·5 2.6 10.7 1.2 7.0 1.8 10.5

·5 3.6 .9 6.4 - - .4 3.1 - - - -- -

27.4 38.2 3.7 3.7 • 79 .86

As will be Mentioned again in relation to Sab~1 it is difficult to accept sGme of the incl'Gment figures reported by Endacott. They aeem far too low for a logged otam. In fact, to about 40 cos diameter they are very similar to unlogged increments in Sabah am such count~J differences are not like~ in so similar conditions.

The reason is much more likely to be in the probably not representative stands included in tl.le C.F. I. plots that :nro:luoed the data. I beliErve incrementa in typical logged forests are going to be much closer to 1 em/year for a much lollgftr period i.e. from a smaller size - about 10 ems diameter on Sabah data. Reyes ( 1959) quotes growth data. from Baailnn in s.w. Mindanao that are considerably higher than those of EJda.cott even though they show the marked rise with increasing tree size. The average he quoteo is .99 ems~· If this figure ( i.e. 1 em) io used and 1~ mortality per year we get:-

TABLE 34 Yield Projection Using 1 em M.A.I.

Neroh. Vol. Vol. a.t Year 0 March. Vol. K.A.I.

Mi l¥1.ana.o

30 yrs 40 yrs

Y..,isa,yas

30 :trs 40 g'rfl

84.4 140.8 5·5 5.5 2.6 .3.4

Luzon

30 yro 40 yra

51.9 85.3 3.7 3.7 1.6 2.0

This bri~ Mindanao and the Vieayao much closer together and this is reasonable considering the good stand table in the intermediate sizes in the Vis~. Luzon ia well down but certainly harvestable.

It is clear fr01n the above that much depsmo on the reliability of the basic Jata. Ny own view of logged increment haa just been noted. In the matter of stam tables, too, oome of the really exc.~ellent forest seen in llorthem Luzon makes mo doubt the Luson d&ta ( unp.1bliahed diary reports 1970). Admitted~ some of theae foreata were being

- 37-

destru.oti vely logged, but the potential for vecy fine logged stands was there. Such stands were eEten in Apayao and Ca~ and quite fair stands in other North Eastern Luzon Provinces • .Many al.so had abumant seedlin& regenerati.un waiting for release. Thus, I auggeot that volume incrementa as given in 'fable 34 are more realistic than those of Table 33, even thouBb the latter have more data backing.

It would be good to be able to a~q ~hat one parameter was of overriding importance, o~ increment or stand table. Unfortunately this is not possible. It is apparent that they mua·t work together. There must be a good after logging stal'Xl on which a good increment can operate. It does see~, however, that 1~aidual stands with relatively good stocking in the upper sizes i.e. 50 em aDd above, are what should be otrived for, since Erdacott baa eh~wn thee~ to have better increments and higher volumes. In any caae, where the commercial stand does not constitute the whole stand as in a logged forest, it is axiomatic that the raore trees of coamercial species tha.t can be retained undama.ged the greater the yield will be at ~ eat time.

6.1.1 Treated Stands

The e£~ect of t~tment has not been widely studied in the Philippines but Revilla ( 1976) gi·~tea a figure of 1.22 CliJ/year diameter increment for small trees in an a.lmoat clear cut area of Mindanao. This ar.d observations indicate that the reaponae het't' will be similar to that fowxi in Sabah, i.e. about 2~ more than in a purely logged over stand. (See 6.2 Sabah, where it is ehown that this increase produces a greater increase in volume - &.bout 1.6 times). If treatttent ever becomes standard practice volume incrementa to 'be oxpec ted could then be (using the data of Table 34}.

TABLE 35 Expected Voluma Incremento after Treatment

Mindanao Viaayas ·~ Luzon

30 ,yre 40 yrs 30 yrs .4Q.. · ·!! 30 yrs 40 yra

Expected M.A.I.

It can 'be noted that on eome areas visited in E. Mirdanao where axtene1.ve enrichment planting or ~calyptus deglu.eta waa taking place., the residual sta.nl ehould respond in exactly the same way as if it vas treated. 'rhua the volumee of Ta.ble 35 met\~ be attained without treating in the traditional manner. As discussed in para 7.1, th8 retention of residuals where enrichment in practised, serves no useful purpooe, but while being retained they will reepoJ¥1. aa shown.

6.2 Sabah

6.2.1 Residual Stands

The figures for undamaged trees froaa Table 9, 10 and 11 have been combined with area weighting &!ld increased by 1~ to allow for inconaequenti•·l damage (the figure derived from Table 14) t.o give a typical after log@"ing stand tor the area near Sarvlakan. This would be fairly level country with high rainfall am represents one of the major forest types of the ooWltry (Type B of i'ox 1972). The stand ia given in Table 36 below.

Another major type (Type C of Fox 1972) is represented by the data in Table 16 from more h:i.lly areas Wl t.h a much lower rainfall near Tawa.u. 'rhese a.re a. leo in 'f:'able ~6, ani the two aota ID8&J18d to give a fairly t,ypi.e&l country averap residual stand.

'l"he firet four pointe fall on a good curve vi th the laat appearing too high. It has been reduced to 1.8 for a better fit, even though theee larger treea aN the high volume producers.

-38-

TABLE 36 Residual Stand Table - Sabah

Size Class (ft. girth & oms. Diameter)

No./ha Sancta.kan

No./ha Tawau

Mean Adjuated Mean

1-2 1Q-19

6.2

6.8

6.5 6.5

2-3 19-29

6.1

3.6

4.8 4.8

3-4 4-5 5-6 29-39 39-49 49-58

4.3 2.8 2.5 2.2 1.5 1.8

3.3 2.2 2 C> 1

3.3 2.2 1.8

1-6 1o-58

21.9

15.9

18.9 18.6

It is interesting that these data agree almost exactly with those of Fox (1972, page 203) who used slightly different criteria for inconsequential damage, aDd adds weight to thie 'after loggi~Ag' stand table.

It is also in cloee agreement with country-wide data collected in 1964 (Nicholson 1965) for sound Dipterocarps over 39 ems diameter. These averaged 4.8/ha; comparable to the 4.0/ha between 39 and 58 oms only, given in this synthetic table. The data in Tables 18 and 19 being provisional, have not been incorporated. However their inclusion makes very little difference, and tend only to very slightly inflate tbe volume potential.

6.2.1.1 Untreated Stands

Not a great deal of inf~r=ation on rates of growth of residuals in untreated logged forest has been collected. Anon. (1964, page 21) shove a mean increment of 1 em/year bfttween 10 em am 58 em ( 1 and 6 ft girth) with very little variation between the size classes. Pox ( 1972, page 307) reports on an untreated stand 41 years from logging where incrementa varied from .6 to 1.3 em/year between 1 and. 6 feet girth. At this age the smaller trees would have been suffering severe oompeti tion. It would be reasonable to use a figure of 1 em/year for all sizes and the error if ~' would be on tho safe side. llortality has been applied at 1~ per annum. With this data the projection to 30, 40 and 60 years is as in Table 37.

TABLE 37 Projection of Untreated Advance Growth

1-2 1Q-1 9 -

Stand Yr 0 6.5 Stand Yr 30 iferch. Vol Stand Yr 40 Kerch. Vol St&.nd Yr 60 Kerch. Vol

2-3 19-29

4.8

3-4 4-5 . 29-39 39-49

3.3 2.2 4.8

Size Clasoes

5-6 6-7 . 7-8 49-58 58-68 68-78

1.8 3.6 2.4 1.6

10.6 9.8 4.4 ).2 2.2

14.1 13.4 3.6

2'1 .9

8-9 9-10' 1Q-11 11-12 Total IQI 78-87 87-97 97-10? 10~-116 -

18.6 1.3 13.7

10.1 30.5 1.0 1.5 1.2 12.5

11.7 11.5 so.1 1.3 2.6 1.8 1.2 1.0 10.2

20.4 17.2 13.6 13.1 86.2 1.4

Volumes have been calculated from 58 em diameter am up, and use Fox's ( 1972) regression BQ".&ationtt which gives lower volumes than Howroyd and Alabazo ( 1954) especially in the upper sizes. They then, 1111¥ be an undereotima.te also.

* Volume in oubio teet hoppus • -192.76 + 48.24 x girth in feet. Volume in cubic metres • Volume in cubic feet boppua x .036054.

- 39-

6.2.1.2 Treated Stands

The actual tl\.,a.trnents gj.V3n to logged stams in Sabah has been well reported (for example Nicholson 1965, Fox 1972 page 196, Anon. 1972) and need not be described here. Tho a6gment coarnon to all treatments (up to 1976) and which has the greatest effect on early increment and hence rotation, is the killing of all non-commeroial trees immediately after logging. Various lower limits for this treatment have been utJed. This was the first silvicul tural treatment of Nicholson and the second of Fox. Th,r- is, too, a considerable amount of information on increments of advance growth in treated forests for the first few years after logging. Anon. ( 1964, page 21, 1965 page 4) shows values of around 1.2 CflJ/year. Fox's (1972 pages 292, 296, 299, 304, 307) data shov mean increments in exceos of 1.25 em for each oize class over 2 ft. git'th ( 19 em diam). Most of these aruat have been residual trees due to the time from logging being of the order of fifteen years allowing only the f'asteat treeo of the seedling crop to enter thie diameter range. Chai ( 1978 Pers. Com.) gives similar data i.e. 1.27 omofyear for the best 100 trees/ha. over 19 em di'Unote!' in treated forest near Sandakan, a.t about 17 yeara from log.gtng. A conservative estimate of tho oftect of treatment would then be an increase of 2~ in diameter growth. (Anon. 196d page 21 showed no advantage in favour of a heavy treatment over a lighter one. The former poi eoned all non-cOIJID8roial trees over 5 ems while the limit for the lighter ono was 15 ems diameter).

Ca.loulations using the same original stand as in Table 36 but with this increment of 1.25 em/year and by the method more fully deacribed UJ¥ier section 5.6, giveo the 30, 40 and 60 year otam.o am volumes vi th 1~ mortality per year aa in Table 38.

TABLE 38 Projection of Treated Advance Growth

Size ClWJnes

Total

30 Yr Stw: 3.5 3.2 2.3 1.7 .e .2 .02 13.7 Kerch. Vol. 13.9 14.0 13.3 7.6 2.3 .3 51·4 40 Yr St 1.4 2.8 3.0 2.3 1.6 .9 .3 .1 12.4 Mercb. Vol. 12.2 18.3 18.0 ~ 5.3 10.2 3.9 1.5 79.4 60 Yr Sta .6 1.7 2.3 2.1 1 .6 1.1 .6 .2 .04 10.2 Jlerch. Vol. j.6 13.3 22.0 23.7 20.9 16.3 9.~) 3.7 .B 114.2

JCA.I

1.7

2.0

1.9

It seems quite clear (Tables 37, 38) that even with the low degree of control being exeroiaed ovex- logging, that a. significant volume can be obtained after 30 yeare frorn felling. A.ey improvement in logging practice that preaerves more of the advance growth muet have a marked effect on thi• intermediate yiold. note too, the significant effect of increasing increment by treatment. Thia io not achieved juet by a proportionate increase in volume. The effeot is oonaider.ably increased by the spreading of tho ute~ into the higher volume produciJl& sizes. It ia felt tha.t this is not a.n artifact of the method of yield calculation.

1'he treated volume a.t 40 years i.e. about 80 m3 ia almoat 900 cu. ft. hoppus per acre, a figure often not exceeded in the virgin cut. That these estimates are not ovel'-optimiotio is ohown by the example of foreot re~nera.tion given by Brown ( 1950), Meijer ( 1970) and Fox ( 1972 page 323). At 21 yeare after a hi~ lead. logging that extr.acted 1062 cu.ft. hoppus/acre ( 94 m3/t!4t) with probably no leas devastation tha.n this method usually leaves behind, there vas 450 cu.ft. ( 40 m3/ha) assessed on the area. At 41 yeare an actual logging removed 809 cu.f't. ( 72 m3/ha.) but 1385 cu.rt. ( 123 ml/ha.) over the

-40-

felling limit had been assessed. ED.mplea of 40 year stard tables in the same area giV$n by Fox ( 1972 page 322) show similar or bet·ter numbers of treea/ba to those given in Table 37 above though it was a high lead operation. It is probable that Brown's fisures ware not taken f:-om the identical areas sampled by Xeijer and Fox, ao increment figures for the 20 intervening years calculated from these data. may be imccurate. They a.ro:-

Bro'*l 's data

( 1) 1928 logging (strictly) 40 m3 /ha (2) 1928 & soma a little later 72 m3/ha

Fox's data

123 m3 /ha ~ l3 m3 /ba.

M.A,I.

4.2 n-;3/yr

2.6 ~/yr

Data ( 2) are probably reasonable and are similar to the M.A•!• figure from Table 38 when calculated between 30 ani 40 years, viz. 8D-52 + 10 • 2.8 m /;~r, but is higher tbD.n the correopol'liing figure ft'Om Table 37, i.e. 51-31 .; 10 • 2.0 m3;yr. Perhaps thio indicates that the e~verity of the 1928 logging plus the cutting of firewood for the steam yarders, ieijer ( 1970) 1 may have approximated a silvicultut"al treatment for the residual stam. Another reaoon is that assessed volume included defective trees as none of the above authors mention det'e~t. Though 123 m3/ha "as assessed. by Fox only 72 m3 was aotu&l.ly harvested. Though the same would apply to Brown's data, some of this difference, at least, could have been caused by defective trees.

6.2.2 Seedling Stando

It baa been shown above ( pa.ra. 1.1) that Dipteroca.rp seedlings noed release from competing overwood before significant growth takeo place. On a loggE~d area with ita broken canopy there are ~onditions varying from areas with ample light to those hardly affected at all, with seedlings ahowin; the appropriate response on each type. Poison girdling of understorey ani useless tre,. ... was employed to give uniform conditions of' ample light and apace over the whole area a.nd a uniform regeneration crop. From an early date there were many auggeotions that suuh a treatment was producing too many young trees and fears of stagnation &Di the need for subsequent thinning were voiced. The point being made here is that if ouff'icient seedlings to fully sto~ the area are induced to grow by the logging, then treatments could be dispensed with. Chai and Udarbe (1977) argue just this point but f'rom the point of view that as logging damage is oo oevere the area that needs treatment ia very small and not worth doing.

Early in foNot reooa.rcb in West Jlo.laysia the fact that only certain trees were "cropn trees wa.o Maliood, tho\18h what waa the optimum stocking could only be gueoaed (Sangater-Daviee 1937). The reporting of oample plot data in terms of certain numbers of the largest trees per hectare vaa a recognition that all trees are not necessary for the final crop and indeed cannot be. Numerous publications ouch as Anon. ( 1964, page 21) use inoremont data for the largest 400, 100, 62 arvl 50/ha, deperding in theocy, on the age of the otam. However, ao long as the otand ia properly regetlerated, with a young forest as opposed to climber tangles, there eee!DB no reason why the increments on a..s f'ow trees as the final crop, carmot be used throughout ita life. This proviso is 1!3ade becauoe evidence seems to show that for young eaplingu at leaot, densely stocked areao return better growth rates o·n th•' crop trees, that1 areas with few trees growing amongst olimbero and other low trees. The early return to forest con:li tiona oeema important ani at thio stage basal &reD. is lees so (Anon. 1961 page 14; .Fox 1972 page 323). The only definitive diocuasion on final spacing for Sa.bah trees that I have seen io in Fox ( 1912 page 319). Usin& considerations of basal area, canopy density and crovn/atem dio.meter ratios, he develops the folloving optimum atooJd.J).~ rates ( hio figures converted to metric) ..

TABLE 39 OJ!timum StockiJ;tg

No./ha

B.A./ha

63

42-67

13.1-20.9

- ·+1 -

Trees of D.B.H. ems

73

32-52

13.4-21.8

83

27-42 14.,6-22.7

The first of each pair of figures being at ~ canopy density while the second repreoonta the numbar possible at near~ ~ density i.e. touching crowns at square spacing.

Thuo he r1ghtly deduces that 50 trees/ba ia a reasonable number of stems from which to calcula~e growth rat~a. From a consideration uf volume produced, 50 atoms at 63 ems should give about 220 m3 ,/l1a, a figure which r1J111.Y be too high to hope for in practice, ao 50 stems &till allows for soaa reduction.

6.2.2.1 Untreated Stands

Again, beca~tse of the introduction of' silvicultuml treatment soon after mechanized logging began, there i1 no long t&rm data for untrtsated stands. Early growth data is taken from linA increment pl~ts (Nicholson 1957, Anon. 1960 page 13), or from small ~reae of almost )lUre or specially treated !'tt~neration, both atypical tor growth in large acale loggirtg areas of the 60's and onwards. They can ~owever~ be used to back up short term d.ata.

Anon, ( 1964 page 21 and. 1965 page 4) ahowo increments for typically logged area.o, of:-

TADLE 40 ~ical Diameter Incrementa in Untreated Star·d . .::_

2-) yr old saplings

l-4 yT old aapliDgS

4-5 yr old saplings

400/n..·

1.1

0.6 1.0

100/ha

-

Though tt.a 62 treea/ha were not neoesea.rily evenly spread over the experimental plota, as were the other ratee, a atoo.king of 50/ha would approxiute to 1.3 .:;m/year or possibly be a little higher. Corrobor.at1ng data trom the early line plots eatimatea rotation agee to 8' girth ( 78 em diameter) of between 54 to 82 years for the common lighte1~ wooded Dipterooarps. If' we taka 70 years as a reasonable mean, then "the M.A.I. to 78 ems dinmater is 1.1 em. {The r&Jl8'1 would be 1.4 - .9 em/year). Au theoe d&ta were taken from areae of unapeoified forest conditions, all probably denser in te1'm11 of ba.a.l a"& ttu1-r. current reaidual forests, and from unspecified rwmbere per hectare, they do agree fairly well with t~e 1a-:.ng etanda of' Table 40 and show tll•t growth rates of about 1.3. em/year to a low of 1 cmfyear can be uintained in untreated forest on the crop tre•a. (The figure uoed in section 6.2.1.1 above aluo agrees).

ir;e can then caloul&te likely f'uture stands of 50 etems/ha at a nUJDbej." of possible diameteT in~reants. We ha.ve selected 1 cm/Yfiar, 1.3 om/year, and 1.3 em... for 20 yean falling to 1 Oflj/year for the re-.il'¥ler (Table 41). The method is that described in section 5.6 except that zortali·ty is not allowed for, as the 50 t:Nia/ha do not ~~resent the full atockin& and there will always 'be those that oan take the place of dead trees.

- 42-

TABLE 41 Projections of Seedling Stand.a to 60 Years

1 •

30 40 so 60 70 80 90 100 110 Size Vol/ha M.A.I

Tree ~ize Mean Jleroh

I (1) 1£"'Ll.oar

Year 30 50 30 - -Year 40 50 40 - -Year 60 50 60 190.5 3.2 '

1.3cmf.Iear ,1

I . ( 2)

lear 30 17.1 22.1 9.4 1.4 I 39 5.3 .2 Year 40 12.0 20.6 13.2 3.8 .4 52 74.s 1.9 Year 60 5·9 15.1 16.2 9.3 3.0 .5 78 351.5 5·9

( 3) 1 • 3c~D/vear for 20 years then 1om/year

Year 30 24.5 [ 21.0 I 4.5 [ 1

36 I - -Year 40 24.5 21.0 4.5 46 17.1 .4 Year 60 24. 21.0 4.5 66 I 244.2 4.1 5

It ia unlikely that thaae volumoo ~. ba reaC\bed in untreated forest. Besides the Dipterocarp advance g.rowth diacue.afld in 6.2. 1 above, tne.r. will alw~a be noa-coumerci.al treeo that will reduce the otocking ot' the aoedling ate.:-..i.

6.2.2.2 Trea~ed Stands

•

Th:! main effect of treatment with regard to the seedling population i9 to increase the nu=ber of faeter growing planta, ratbar than increase the maxi~ ratea attain~d. That ia, even on untreated areas there will ba some plants :n'O'Wing just a.a 'ftwt aa if they had been treated due to \be very broken nata1-e of a recently logged t'ltand (see 6.2.2 abov~). Ho~ever the effect w;ll be to incre~se the mean rates of growth. Some of thea~ s.~ .. ~ given in Table 42 below, atri aioe from Anon. ( 1964 page 21 ani 1965 pa.ge 4).

TABLE 42 1lf.ical Incremento in Treated Stands

400/h& 100/ha 62/h&

2-3 year old sap~ingo 1.4 -3-4 yeBr old aeplinge 1.0 1.6 1.6 4-5 year old ~plingo 1.0 1.4 1.5

It can be aa&Wied that the effect of treatment on inoreaen·C; 'Wi:' 1 ba short lived (maybe of the ordf!r of 10 yea.rs) as basal area bui lda up. But the early increaoe wi 1 ~. have been impunant in aeouring dominant poai tiCJD'J for more of the oro? tree a tt"UI er.suring the continued growth and · .. he hi~er representation of Dipterocarps. !t is more probable then that vol\l.llt>3 p!'oduction wi).l be of the order of increment group ( 2) in Ta~·:A.e 41, tllan of the Wltreated sta.n&.'\s.

The Tot a~ S t&nd

The diacuaeion "';(>. elate h..;.t~ c-~uiderel.. the advance growth and r· eedliJ188 separately, whereas th.ty togethttr nonati tute p,al-:'~8 of a single utami. Some synthesis is therefore .needed... It can be &ll£.uat'-d tnat tha seedling population topther wlth all the regenerating non-ooaasroial ~reee will efftl~tively 1 fill-in' below the advanoo growt:l a.nd that reductions

- 43 -

in numbe~ or volume growth due to the ~resence of both stands on the one area will occur mainly if' the younger portion. Thus Tables 37 and 38 can be taken as th.ey are but some l'\:,•duotion in Tab~e 41 is needed b'lfore adding to the advance gi'Owth volume. 'lbe basal area summary of the stands in T.ablea 37 and 38 are:-

TABLE 43 Swnu1acy of B.A. 'a in Table& 37 arxl 38

T.able 33 - Not treated

At 30 years

At 40 years

At 60 years

Table 34 - Treated

At 30 years

At 40 years

At 60 years

3.65 m2/ha

4.51 m2 /ha

6.05 m2 /ha.

4.68 m2/ha

5.92 m2/ha 8.42 m2/ha

If we assume that aboui ?.3 m2/ha io an optimum total baeal area that still allows plenty of growth to take place, it can be sean that tho advance growth takes up a. relatively small proportion. The remainder will. be seedling Dipterocarpa, other coaaercials, weeds, or ~ be vacant. In an endeavour to determine the relative proportions of these components only a little published data waa found am is in Table 40 but much more widely based data could be obtained from the series of yield plots in S~bah.

TABLE 44 Proportion of Dipterocarpa in 40 Year Old Un·treated Natural Regeneration

(after Fox 1272 A:pendix 19)

Size Claas No.}iw. D.A./ha Dipts. All Dipta All -

10..19 30.2 15 f .2 .51 2.63 19-29 10.~ 56.4 .48 2.62 29-39 6.2 24~3 .56 2.21 39-49 5.2 16 .. ; .78 2.47 49·58 4.0 9.3 .90 2.08 ;8-68 2.1 4.5 .66 1.41 68+ 3.0 4.7 1.43 2.23

~ Di2!! ~ DiEl! Total 10 ems 61.0 272.9 22 5 .. 32 15.65 34 _,.. -Total 58 oms 5·1 9.2 22 2.09 3.64 21

Younger stands, even ;,n ti'O&ted areao do not show such good Dipterooarp repreaantation. For example, Anon. ( 1964 page 18) ahowa Dipterooarpa (over 10 om diem.) ad··.anoing froi4 19% to 28/:. oi' t-ho basal area over the pe1~iod from 6 to 9 years of age. Ch.ai ( 1978 Peri'. Comm.) prcvi.df:Kl one yield plot at rtmiom which gave the Dipterooarp representation of 2~ over 10 om diameter a.nd 65'$ over 58 em diameter ~t ag• 15 yeaN frOill logging ( plot 10 Segaliud F. R.). The laat figure does mt ~ooepreaent the ~ff'ect of e;Nwth only but ot• reducing the non-Diptei'OC&T'P fmo·Gion in tre&tMnt. lfowever ~vidence ohows that the Dipterooarp representation does iaoreaae with age, with respect to baaal area and therefore volw:H. The above figures oan only be a 'V81':f rough @Ui.do a& much more widely bued data are required.

-44-

They do point to the probability that at leaat 5C1J, of the stand. volume will be Dipteroca1'1S& at an i~termldi&te harvest.

We now have aoae oluea u to the total volume that might be prodt:·,c.ed under different increment regimes. It should be etreaaed. that the data are apeoul&tive and give only clue• as to the order of productivity. Table 45 is a &l.UIID&ry of such production.

TABLE 45 Summaty of Volume Production- Sab~

INCREME'NT RmiKE OF SEEDLillOS

A. UNTREATED

30 ym from logging Advance growth Seedling Vol x 5($ 'roTAL & (M.A. I.) .

40 yrs from logging Advance growth Seedling Vol x ~ 'roTAL & (M.A. I.)

60 yra from logging Advance growth Seedling Vol x 5C1f:, TOTAL & ( II.A.I.)

B. TREATED

30 yro from logging Advance growth Seedling Vol x ~ 'roTAL & (H.A.I.)

40 yrs from logging Advaneo growth Seedling Vol x 50/. '10TAL & {N.A.I.)

60 yrs from loggi ug AdvicUlce growth Seedling Vol x ~ 'IOT.lL & ( M.A.I.)

1 em/year

30.5 0

30.5( 1.0)

50·1 0

;o.J( 1.3)

86.2 95.3

181.2{ 3.0}

51.4 0

51.4( 1. 7)

79.4 c

79.4( 2.0)

114.2 95.3 ~-2i ~.~)

1.3+1 em/year 1.3 em/year

30.5 30.5 0 2.7

30.5{ 1 .o) 33.2( 1.1)

50·7 so. 7 8.6 31.3

59.3( 1.5) 88.o( 2.2)

86.2 86.2 122.1 17;~8 208.3( 3.5) 262.o{ 4.4)

51.4 51.4 0 2.'7

51.4( 1. 12. 54·1( 1.8)

79.4 79.4 8.6 37.3

88.0( 2.2) 116. 7( 2 .9)

114.2 114.2 122.1 175.8 236.3{ 3~.2) 290.o(4.8)

The u.rvlerlined figut-ea in Ta';)le 45 are a aeleotiora of likely increment l"Bgi~~es that could prevai 1. It can be seen that volume production rieea •teeply after 40 years due to the inclusion of the seedling sttmd, but at beat it is of a low order. One DJ&t remember that in the untreated stands eapecis.lly there will be & amsll volume !"rom non-Dipterocarr advance growth.

- 45 -

6.3 Sarawak

6.3.1 Residual Stands

Hutchinson's projections (Hutchinson 1977), though making allowance for, (a) th~ differing growth ratee of trees in differing crown illumination classes, (b) differing mor-tality rates and (c) ingrowth, are difficult to Ampare with my simpler projections as the trees over 58 ems diam~ter are not presented in classes and so it is impossible to calculate volumes. Neither does he do this himself.

However using Sabah growth data on the undamaged fi~res in Table 28, the following projections cs.n be made, using an increment of 1 cm7year (which agrees well with tne median figure of Hutchinson) and disregarding recruitment.

TABLE 46 My Projections of Sarawak Data

( 1) ll'.ortali ty 1%/year

Year 0 Year 30 Merch Vol. ·:ear 40 Merch Vol.

110.7

( 2) Mortality ~/year

Year 30 Merch Vol. Year 40 March Vel.

4.0

Size Class

5·1 2.51 2.96

11.0 18.1 7.15 2.27

31.5 13.8

5.89 1.87 8 .. 2 4.82

21.2

3.77 36.2

2.88 27.6

2.37 2.81 18.5 27.0 1.80 1.94

14.0 18.6 2.30

26.0

Total M.A.I. of Vol. over Vol. over

ems • ')8 ems.

132.3

67.1

89.1

2.3

It is evident that the good resid1Jal stam l1ere has a marked beneficial effect on volume production. Even at ~ mortality ratti the volumes over 58 ems diameter are quito b.arveotable.

6.3.2 Seedling and Treated Stands

In Sa.ro.wak there is a full accaptance of an intenaivQ ailviculture.l treatment in the "owamp for<Jsts" and reoul ts are good (Lee 1978 ani pam. 2.3 above). However great caution is beir.g UkJdd before ouch treatm4!mt is introduced in ths dcyland Dipterocarp foreots. Experiments cowring quite extensive a.reaa anli different treatment methods are eeta.bliohed and it is confidently expected that results of canopy opening will be just as marked in favour of the Dipterocarps a.s in other countries. Indeed response of Dipterocarp seedlings only a few montha after a heavy treatment was alre.fldy very marked. The type of ota.Jld, wi tb a x"tllat1vely low me1·clua.r.table volume am low rates of logging damo.go, lends i ta9lf very well to such a canopy treatment. Hutchinson ( 1977 page 132) fima that 20 year old etanda, without treatment, already have a higher proportion of desi~bles than unexploited forest. Tl"'Catment causing response in the aeedlingo without the atttSndant damage in logging can only accentuate the proceen of eta.nd improvement.

However, the better after lof!ging Stand Table ( 'l'e.ble 28) ar..d the ooru.;equent 1J!UCb

better volume prediction (Table 46) appear to le."'sen the need to ensure rap~~ ooedlill8 development. The F.A.o. team is working along th_.-.je linea at present, with the aim of stimula.tin3 growth on the advance growth treee by traating arow¥1 them Ot·;._;. It' this proves

-46-

as effective as a more general treatment in raising increment i 1: should improve volume p~uctiun in treated stands by about 1.6 as in Sabah, giving 30 and 40 year yield a of 153 m3/ha and 211 m3,/ha respectively (using 1% mortalityj withuut any contribution from the seedling stand. Deducting the volumes over. 58 ems at year •-ou, these would be equivalent to M.A.I,•e of 4.4 and 4.7 m3jha respectively.

6.4 West Ma!alsin

Though the two sets of data in Table 22 ca.nnot bo re~resentativ\1 of all the rema:lning forest in the whole country they probably e.re mere so than the data for Kupur Forest in Table 20. The mean values of the two sets, vbioh are conflicting in themselves, are therefol.~, the best data we have at present.

By extrapolation back to 10 ems am on to 60 ems diameter and interpolation to make 10 em classes a synthetic stand. table as in Table 47 has been made.

TABLE 47 West Malysian Residual Stand Qf Dipterocarp Stems

Si2oe Class

1G-20 20-30 30..40 5<>-60 Total

Ho./ba 3.0 2.0 13.2

It is clear that thie stam. is DUmerically c:uoh poorer than a~y "'f the other countries of the region. The volumes expected from these residual trees will be relatively lov am are given in 'rable 48 below, uein« Sabab volumes and uaing & 60 em cutting limit for comparison.

TABLE 48 Expected Volumes from West Mal.a.y!Jian Residual Stanis - Dipterocai,'PB only

Untreated ~eo ted* Size Class Volume 'l'reat. Vol

4Q-50 I 50-60 60-70 7o-80 BD-90 9Q-100 100-110 11Q-120 Total MAI Total MAI

30 yr. Stand lleroh. Vol.

40 yr-. Stam Nerch. Vol.

60 yr. Stand Mercl1. Vol.

3.1 I 2.2 1.9 1.5 , .1 8.9 9.8 9.1 27.8

2.8 2.0 1.7 1.3 1.(' 9.4 11.1 10.8 10.1 41.4

I I 2.3 1.7 1.4 1 .1 .8 14.9 14.1 14.1 13.1 10.9 67.1

* UntN&ted VollliJW increased as in Sa.bah, i.e. in the ratic of the data in Table 38 to that in Table 3 7.

.9 46.7

' 1 .o 64.6

1.1 88.6

Unin~ the a~ ae&iltng d&ta that were used for Sab~1 (Table 41) we can arrive at Table 49 that only abowa totals ani JI.A.I. 'o but ia conatructed in the BWDB wa.,y aa Table 45.

1.6

1.6

1.5

•

- 47-

TABLE 49 Sumraary of Volw.2a Production - West Malaysia - Dipterocarps on1Y_

A.. Untreated

30 year s tarn AO year stand 60 ye&r stand

B. Treated -·-30 year stal¥1 40 year stand 60 year at&Dd

1 omftr

27.8 ! .9) 41.4 1.0)

162.4 2.7)

~eedling Increment

1.3+1 cm&r

27.8 ( .9) 5().0(1.3)

189.2 ( 3.2)

46.7 ( 1.6l 73.2 1.8

210.7 ~3-5

1.3 cro/yr

30.5 ( 1.0) 78.7 (2.0)

242.9 (4.0)

Because ot the higher non-Dipterocarp fraction in Mala.yan Vorestu (about ')(11, of reaidua \s) and the acceptance of more or tbeae by the mEu'icet it ia likely that the volumes as givsn will be considerably au8'1Jented. However aa they stand they give " COOlparison with Sabah, and are seen to be a little lower~

6.5 Ind.onesia

Since it was not possible to fit'Mi rep.:·eaentative after logging stt..rd tables in sufficient detail, un which to base a projection, this was not attempted. Indications are that incrementa will be of the Ba.IHI order as in other oountrias. For example Saatroaumarto ( 1978 page 11) euggesto a ~ean annual diameter increment of 1 om or more, which is in agreement with other data used in this paper. However Sutanto 6t al (1978) fi£~& lower values. Soedjarwo ( 1978) eBtimatea v\>lume increment of between 1 ani 2 rn3/bafyear whioh iu quite aimilar to estimates from Sab&h (Tables 37 & 38) and West Ma.layaia (Table 46). Thflre is then every reaaon to expect such a retum. Though, with the husa areas involved, tbia relc..tively low figure will amount to very aubatantia.l vol\U'Ges, the -return per hectare i£> a till low. As with Malaysia ( a.ll regions) the virgin stands do give scope for improve­ment, and as we have ae~n earlier ( P.EU'a 4.5.2) there is room for improvement in logging practiceo and so retain a better 1 esidua.l stand.

The effect of treatment must be similar to that reported for other oountrieo, both for advance growth (Paras 1 .. 1; 6.1.1; 6.2.1.2) and oeodling'8 (Paras 1.1; 6.2.2). It is specified for e~.rea.o reotd ving the modi.fied Jea~an uniform system.

6.6 A Note on Coots

The foregoing mention of varioue. treatments and lo.tet• aantion (para. 7) of better logging practices only consider the ailvioulturw.l poaaibilitiea without c~naidering the coat a.ngle. Othel"9 are atucl,yifl8 thicl aspect more deeply than I am able to do, for exampl~, the FAO teruna in West Malaysia inoluding Andel am Hutchinson. However, it must be olear that if volume production can be maiu.tained CJr increased by preaorviJ18 as much of the advance growth aa poReible, thiii 1nuet. be given first priorj"y in the whole logging/t"&tment regia1e (see alcu- Fox 1972 page 314). As an illU9tration the following oimplif'ied data. ia s:iven.

Diameter of a Retg.ined Tree

em -20-30 ( 25)

30-40 ( 35)

40-50 ( 45)

50-60 (55)

-48-

Equivalent Volume over 60 ems at 40 yrs., at 1 em diam. M.A.I. with mortality at 1~ and volumes from the regression given on Page 38

3.2 m3

4.4 m3

5.6 m3

6.8 m3

At the high prices being obtaim::i for wood at the present time, the good eense of preaervi.ug as many of tnese t~da as possible is plain.

Andel ( 1978) ahowa from one eumple thd.t proper logging contrc,l in West Malaysia may add. JCS5·1-70 per ha., whereas a post logging silvicultural treatment (including planting of landings and roadaidos) may coat about Ml200/ba., or about t\lienty man da:Ja/ha. He gives the la1;ter figure as ~ 'high; in the general range of treatsnent cuats, ar4ii from rt13 own experiunce this certainly is so, but the relativity of the eoats of logging control ~nd post-logging treatment probably is of the right order. Even if more nearly equal, the l't!pair of a bad logging opel'Btion by post-logging treatments must be more expensive when one cons1ders that the only available replacement to a deotroyed tree, is a seedling which will t&ke ao much longer- to produce saleable wood.

Therefo~, though it can be shown that advance growth io greatly benefited by freeing from competing trees, the preservation of the tree in the first place is of mGre vi tal importance.

6.7 General Aape~te

A otrong improauion, that all the foregoing data on seedling and advanced. regeneration numbers wet surely make, is the amenability of the Dipterocarp forest to proper una~ment. It seems that or1ly cu.ltiv~tion, particularly with the use of fire, but not only oo, ia o.ble to destroy it.. However, too ahort a outting o;"·.!le will have very eeriouu effects on yield, if not on permanence of the Dipterocarpa themselves., Whitmore ( 1976 page 224) warns aga.bwt the~ proliferation o.lf veed opeciea and their eventual dominanc<:t with too frequent cutting. Ther .. again short cycles wi 11 or¥l&fl88r long t~:rm productivity by ou.tting the biggest trees before they have had tbse to aeed effectively. These are the moot desirable ~notical~ and negative selection, for growth rate at least, may occur. Though Revilla { 1976) at~teo that moot Dipterocarp-:-t fruit bef,IN their thirtieth year, thia will also depend on their "?hyoiological norxH tion ~• controlled by their P<'Bi tion in th~ canopy, and fircJt hui ti.ng may well be de!"'ed past this aga h1 natural o:mdi tiono.

Just bow aerioua thil' effeot could be ~.c uot known but ahould be studied. Even the forly yee.r o,yolea su~sted o.bo"e t'n yield considerations, IDa8' have to be lengthened if l!lignifioant •eedirl8 da.e not occur by thi.e time. Certai.nly very ehort pulpwood rotations in o~njunction vi th enrioluaent wi tb tut g~'Owing speoie11 cannot be colltlidered in .lhpterocarp anagement since no •eoding at ~ll will ooour.

'J.lhuo to ensure thfj c"ntinuod supply of Dipterocarp timber the mt'&t i:!iportan·t eingle rn.anageruent objective must be ·~ono protection of forAat reservations from cultivatitm. This cannot be too stroJlBly atl-eaued ( oae alao NioholBO~* ·1970 pa..geo 27 am 38). All other rtio..nagu::,,.L•nt aotivi 1.iea muat be subordinate to this basic one of hD. ;;.ng a forest to manage. This rother c..xiom.atic statsment ia :Dade because of the present pl'easure on forest l.anr.t l::ai '18 felt in all the oc~"•mtries of the region, f'or alienation, both legal and illegal~ by po~t f&l"'MMrs azld by big tusineas in plantation agriculture. Al~v vatJt arear, haw been lAid waste ( aa for '':x.ample, on Bobol and Cebu but not by a.cy :sear~ N.IBtl~oted +.o these

- 49 -

islands nor other areas of the Philippines) or destructively logged because of expected alienation (as in large areaa of Sabah), or actually used for agricultural crops las in say West Malaysia and Sarawak). The suggestion is not being made that no agriculture develop­ment should take place on forest land, but that it does not always take precedence over forestry. The la!d is wornerfully sui ted to producing timber whereas large inputs by way of fertilizer, pest control etc., often have to be made to make the agricultural venture a success. Already certain economists (De Backer 1978 for example) a.re indicating that plantation agriculture may not alw83s have the economic edge on forestry.

These thoughts reflect the concem being felt in many quarters (the lead stories for example, in the Far Eastern Economic Review of December 2nd 1977) arxl though they may not be entirely germane to the paper, are vitally important. For example, the relegation of forestry to the hilly areas where the silviculture of the major species is not so well known and is much more difficult, should not be accepted as inevit&ble nor entirely desirable. Apparently West llal&3'sia has gone to this extent (see FAO paper 1973, referred to earlier in para 2.1) and Sabah is following suit but there is still time here and in Sarawak to save eorne of the better lowland areas. Such lowlani areas competing with other forms of land-use would have to be silviculturally treated and so create a large demand fo1· labour. They would then be able to compete on a sociological b4sio also ( oee also Laursen 1976).

However, assuming that we have a toreat estate we have shown that it can be managed for sustained timber production and be regenerated naturally. Before summarizing these aspects, the other values of the forest should be briefly discussed. They are, in my estimation, all covered in water, wildlife and recreation. By reason of the fact that a forest cover is maintained I believe it can be asnumed they will be provided for also. The wildlife aspect is sometimes thought of as being emangered by loggi~ a.r.Q. especially by silvicultural treatment (Proud 1978). There is no doubt that logging, especially if followed by a severe treatment, will cause changes in the faunal habitat. a!xl theEte may lead to a lowering of speciflc animal populations on certain areas and for a relatively short time.

Even in the otamard version of the Malayan Uniform System the forest is not redut,ed to a uniform condition. For example, many of the food plants of the Orang hutan, listed by McKinnon { 197?) a1-e themselves advantaged by logging and tzoeatment. The parent trees themselves ~ be loot or1 the treated area but the species will be better represented in the regenerated forest. Early in the management history of Saba.h a clause preserving fNit trees from girdling was written into the rulea (Nicholson 1965) and a oimilar exception was retained in their Ma.nu.o.l of Silviculture (Anon. 1972). Such devices can be introduced where the food plants of certain animals are threatened (or nesting si teo or other essential )~bitats). Tho leaving of theae planto will only be ailviculturally undesirable in a few cases, for exam·ple, in the caae of marw !'icu£' !!PP•• and in these in particular, a sensible balance between the claimo of timber production and woll do~ented dependence by certain animals muot be Mde. So long as the population is kept above that required. for contir.ued breeding, the wildlife manager must accept some reduction in the population in th~ interests of multiple use forestry. Nevertheless for certain animals the only oolu·~iCtn may be the creation of special reserves for their preservation.

With respect to recreation, euch reserves aa just mentioned can serve this purpose also, and the aer~ible provision of other recreation areas r~ be made near population centres. The good access provided 'by forest management must enhanc~ the recnation potential of the f~rest u.s a whole. (Presently this aoceas causes more trouble than benefit in that it aides the illegal cultivator in his searoh for new land. It is hoped that strong legislation backed up by action, and education, vill eventually ch.ange this situation).

It is gemtrall.y agreed that theao other "foreut values", particularly wildlife a.&"e nruoh lesa affected by forestry operations, aBi the proble~~.W poiMd are lllllcb less vital (literally), than thoae associated with other land uses.

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1. DISCWSION AND REX:OIOlE!IDATIONS

7.1 The PLilippines

Volume estimates here have taken for grQnted that a qyclic logging will take place, and on Endacotts' data the volumes and incremento of Table 34 and 35 are likely. These make '.1De of increment and mortality rates that are not yet based on extensive Philippine data, but are reasonable nonetheless. Kore concern is felt that the initial residual otam table used is too good. The other stand tables given (Tables 24, 25, 26 and 27) all shew fwer trees. For example, the weighted mean of the two high lead set-upe given by Weidelt (Tables 25 and 26) give 27.8 tre&s/ha over 15 oms whereas Ervlacott gives 5.5 ( Tahle 31) ~, Even with Weidel t' e tractor logged set-up include.., the mean ia only 33/ha. The data are then likely to be on the high aide.

With I'tiapect to treatment it i8 necessary that variants be investigated further, possibly along the lines suggested bv Nicholson ( 1970 page 32), i.e. incre~mnt studies on whole set-ups in conjunction with the residual assessment. The freeing of residuals that are still impeded after the logging, would be a minim&l but possibly adequate treatment.

It muot be remembe:-ed that these volume increments apply only to trees over 55 ems diameter ani when the current felling rule ie ueed. Total volume p1·oduction will be much higher and will iuclude the volume of eJA&ller residuals as well as that from the "seedling'' generation. Not many of the latter will be of merchantable size for saving, but where industrial wood plants are dependant on the forest, there is no reason that a heavy ''thinning" could not be given in thi£l stand at the same time. It is not possible to make estimates of likely volume from this source but it should be high, especially on areas originally treatt!d. Felling at each cycle - I believe thie should be at least forty years (see para. 6.7) - will have to be very carefully done. It should include caref\11 tree markitl8, particularly of about 50/ha of the best of the seedling population for retantion. These would otherwise b~ the first to go to the industrial plants and a negative genetic selection wo~ld take place in respect of ~te of growth and fo~.

However, in some aMas, there is an artificially produced case, real nonetheleso, for uning a system such a.e the Malayan Uniform System, which in dependant on seedling regenera·tion. The presence of large imustrial wood plants in these areas provides an out let for ''amall 11 WCJod. If thin can be harvested economi ca.lly by high-l!'ad methode an effect1ve "ti-ea'tment", an necessary with s,ysteme such as the M.u.s., is done (see para. 6.1 ,1 ubove). High-lead lo1~ging ia specified since it can do leo a damage to the soil ourface aild henna to the seedlings (soe 4.1.2 and 4.3.1.1 above). Th.() figu~a given for area disturba.nce from tractor logging 1. luld be greatly accentuated under such a "clear falling" syetem to the point of making enrichment planting rna.ndatory.

I would hesitate to suggest this aystem of management were it not fox· th.e fact that some companies are already approaching it, with apparent early success. Lip service io otill being paid to Selective Loggi.ng principles but all treeo other than t,h., marked I-eoiduals are being either harveoted or felled a.nd enrichment plantin.g with feat growing opeciea 1s being d~nc. A number of such areas were seen, aa~scially in East Mindanao and in all caavs un excellent stand of natural Dipterocarp regeneration had resulted along with the p lantea. t ':'"-ees.. 'I 'he pJ-esence of the currtJnt roe idual otam ia not necessary after the expcnlle of enti~hment has been made, and mfly be an embarrassment in future. Ae shown above lTable 35) its volume increment certainly cannot match opacieo ouct as Eucalyptus de81U£ta and can only reduce the potential of the latter. It could juo~ aa well have been harvoatod.

•rhis apparently growing h&.b:i. t of enrichment planting in the Phi lippineo is a.n inteNating development and one that stems from the need to oupply the very large (too large •:-) designed intakes of the depemaut irldus"tr::al plants. Tagudar ( 1978) gives an up-to-date acco~1t of it, and the consequ~nces to the milla of not meeting the ~upp~ of wood material.

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Though new to me on such a scale, the following thoughts a~~ offered for guidance and experiment:-

( i) Areas sui table for enrichment are thoDe with a poor residual stand. This must be qua11tified after further investigation.

( ii) The species used for enrichment should not be regarded a.s aeything more than a stop-gdp in supplying wood for imustry, and the long tenn presence of the Dipterocarpa should be ensured. These have a lower volume potential it is true, but their timber is of high quality am they cannot be grown outside of natural forest condition.

(iii) With this in mind short lived and wide crowned species su~h ae Albizia falcataria are not thought to be ideal for enriohment. Thoir rotations are so short that the Dipterocarps below them would hardly be large enough to sustain the logging damage, and the abort felling cycle, would eventually eliminate the Dipterocarps from the stand, (para. 6.7). On the other hand, species ouch as Eucallptuo deglupta can be carried on t~ a longer rotation and can then be felled with less darr.age to the Dipterocarp components. Certainly some very impressive stands of your1g Dipterocarps were seen growing with enriched E. deglupta whereas they were far less well developed under Albizia. The felling of tbt:1 planted t- peciea at an age approximately half the Dipterocarp rotation i.e. at about forty yearo, would give the survivors a much needed thinning, and boost their increment. Since ouch early treatment (the preparation for enrichment planting) h-Teatly increases the number of Dipterocarps that make it to the canopy (see 6.2.2.2 above) it is likely that after the first cycle there Will be no ne6d to do any planting, the full pc.tential being uaed by Dipteroca.rpa and management can revert to Selective Logging. Whether this can be realized will de}lem on the care exercised in logging.

\ iv) While waste la.•.d exists, therefore, permanent wood producing plantations should be concentrated on it. Various Agro-tt'orestry schemes ha.ve been reported (e~g. Tagudar 1978) and seem an ideal way of both producing cellulose as well as settling the pea£ant farmers. ~ut zog regenerated or recently logged Dipteroca!J! forest shot\ld not be oet aside for such permanent plantations. Many areao of oecom growth, if shown by sampling - and not a. curoox-y look from a roadside - to contain less than adequate Dipt~rocarp trees, ~~n be ao converted and w~uld grow the more demaming apeciea such as A. fa lea t9.ria and E. deglupta, while there are species ouch as the Giant Ipil Ipil ttmt will out-produce oi ther of the above even on degraded cogon lands, Mindoza and Semana ( 1977). The economics of aea transport in rafts or barges of ouch f'oreot produce ( poaoibly a.a chips) fran cogona.les on other ialania ,.,.ould seem a very p1-ofi table line of research which could ahow a greatly expanded area. of supply for the existing mills am take the preeoure off the Dipterocarp forest.

1.2 Sabah

Tables 37, 38 and 45 give eatiaaatee of vol\WC production from the advance growth and f·rom the whule etard. Treatment is seen to have a considerable effect on the ildvanoe grori ~ eepent. In this regard it should be remembered that the untreated incre-uent used in Table 37 is based on few data. Though the data from Anon. ( 1964 page 21) came from a typically logged ares. which would have cut about 116 m3/h.a the damage caused was less than later am current logging operations. 'lbeJ'e ia the poaa.i.bility, then, that the treated incrementa used in Table 38 1Da3 be applicable to c11rrent non-trea·ted areas, and that the u.dvant889 of t1~tment 1U3 not be real. It io not accepted, however, that these high dogreee of logging damage being reported from parts ot Sabah are inevitable. Compare within Sabah for example, plot 5 of Table 19 with Table 13 both areas cutting 16 treos/tw. yet with ver.y different dam&Be, or the data in Table 27 fr~ the Philippine& with Table 12 and 13. Thus it is cl&il!led that with more ~Htul logging, needed to preserve a a•lffioient

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residutt.l etam, treatment will be necessary and will give the indicated response. This question of severe logging damage in Sabah is discussed by Chai and Udarbe { 1977) in relation to seedling response. They show 36% bared ground, 30% areas requiring no treat­ment ard 34% area treated. Unfortunately they do not show how many residuals were present. This is important, for if a good residual stam can be left while destroying as maJ\Y of the trees that would be treated, the residuals should grow nearer to the treated ra.te and the logging becomes a treatment. ~ awn recent observations were too restricted to be of any l'ea 1 use, though they did not support this possibility, as nww of the residuals were being destroyed also.

Due to the rather low average residual stand giving 51 or 79 m3jha, depending on treatment, at forty years from logging, Tables 37 and 38, it seems necessary here to use the seedling stand -nore directly. Dy sixt,v years the M.A.I. rises to reasonable rates, with the inclusion of merchantable ttseedling" trees (Table 45). Of the options tested this therefore is the one recommerded for general application. It does in fact, represent a considerable increase in yield since the annual area harvested is increased from one hundredth to one sixtieth, due to the inclusion of the residual 3tatn in the yield calculation. Moreover, it io expected that with careful logging at age sixty yaars, a better residual stand can l'e left than that possible from the virgin forest. This will be especially eo if silvicultu~l treatment was applied at the beginning of the initial sixty year cycle. Thus the next ani fQllowing cyclos will almost certainly be reduced to forty years, as suggested f'or the Philippines. The recomraendation is then for a bridging cutting cycle, from the modified M.u.s. (Anon. 1972) to one that takes account of the yield of the residual stand as its primary concern. Thio, of course, leads to a second major recommen­dation, that more control is exeroia~d over logging to nusband the advance growth componftnt. Earlier suggestions (para. 4.1.1.3) have baen made to this effect, and mu~h of tho data given earlier in this pa~graph ohow that it is possible even without special efforts being made to do so. These uhould now be made, especially along the lines of limiting the area destroyed by tractors to a maximum of 2o-25% and of initiating some system of advance growth marking (the potential resi:iual stand). Thio could be the marking of o~ 20 steras/ha, between 20 and 60 ems diameter rather than a. percer1tage of the stand. Doth of these controls need atrong action backed by effective legialation.

lo'ox ( 1972 page 324) diocueees pre-logging climber cutting and directional felling as other means of enouring a better aftel'-" :>gging atarxl. The latter is essential if marking for retention, as just proposed, i& to be effective. Fox's data in Tables 12 and 13 ohow a max•ked improvement in the residual stand when loggif18 follC\WD a climber cutting by three years. Though !<'ox ( 1968) pointu out some difficulty of direct comparison of those data, it is a line of investigation warranting further atudy.

For the reasons outlined earlier in this paragre.ph treatment following logging ia still reoonnanded, a.t least in the first sixty yeax· cycle. Ar:~ explained in para, 6.2.2.2 one of the ohiof effects of treatment will be to increase the Dipterocarp rep2-eaentation am it is thio that will allow the su.baequent f~lling cycles to be reduced. Treatment effects, then, will be spread over two logging cycles at leaat.

7.3 Sarawak

'fhe data given in 'l'abloo 28 a.l'¥1 46 uriioubtedly ahow a g-ood residual stand ar4£1 volume production. The forty yeaJ• cycle is favoured. It ia felt that as the cur1'Cnt peN-iosable cutting diameter is 45 ClllB, muoh of the residual ata.zxl (the volume producing part} ie due to the reluctance of the industry to harveat all that it could, Note for exa.tilple • that about 11.4 treea per hecta.I-e of Table 46 are above 45 oms diameter, and 5.1 trees/ha are over 58 oma at year ''0". «i1rough I believe 45 ems diameter to be too small a cuttif18 limit, an improv~:"\ment in the market could alter thio condition of light logging damage. But as things are at present, the high proportion of und.iatux'bed area.a (Hutchinson para. 4.6.3.1) indicates that a. ailvicultural treatment is necessary. Otherwise t~1ese unlogged portions ( unlogged b~ca.uae of no commercial ai~ed treee) will rennin relatively unproductive. Though evidence being collected in Sarawa.k ahowo the rapid respo"Ule of uaedlings to

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liberation, present thinkill8 there is to treat for the advance growth alone~ F'inal recommendations must await data from plots recently established to teat the response of both seedlings a.nd advance growth to various degrees of liberation. It seems ~o me that a decision on whether tc treat for advance growth or seedlings does not depeoo on their 1-eaponse f'or we know both will respond well, but on whether there is a oufficient stand of advance growth to treat for it alone. If the data of Table 2 are t:rpica.l then there certainly is scope for relying on the advance growth alone, and so long as residual etande ca.n x-emain as good or better than that shown in Table 28 there ~eed be little worry ao to their volume potential. I would suggest that very extensive sampling be made to show that eoum residuals are in fa.ct so well represented. Though the complete commercial stand shown in Table 28 ia far leas rich than the Dipterocarp data given in Table 2, it is suspected that even it may be too good. It aeems better than a typical stand seen in the Bintulu area. The common problem of finding too maey faulty and very poor crowned trees chosen as residuals, was in evidence also.

If residu.a.ls a.ro going to be relied on for the next cut it is important to preservo as many as possible through the logging. Table 28 shows that even with the relatively light present day logging there ia scope for reducing damage. As suggested for Sabah and as presently specified for the Philippines, the marking for felling as well as retention, is a. positive stop to preserve as many of these residuals aa possible, and is recownended for Sara.wak. The pro-logging sample will show just how many can be marked, or if there are more than necessary, what eizes should be marl::ed to get the required number/ha. As discussed for seedlingu, it is probably not necessary to go beyond 50 stema/ha out usually there w1ll be leas than this to choose from. The ma~ed trees muot, of course, be good species w1th acceptable crowns and ate~ form.

Then, aa discussed above, a Gllvicultural treatment in these lightly lop,ged forests is highly desirable. Presently this is being tasted, uoing what is called a "Liberation ThinninR", whereby only selected trees are liberated. It is seen at once tha.t thio treatment dovatailo in with a pre-logging marking for rotontion very nicely. However, it shifts tho ~sponoibility for selecting the trees to be treated on to the otaff in control of the logging. This is seen as a scum move, considering tho importance of the log~ing in the management cycle. Undue damage to these trees can also be detected and action taken. In general terms, so often Foresters come on the scene a.fter logging and tl"y to dn what they can with what io left. While a uniform system io practised this m.ay be pennissa.ble, but it i9 not with a. polycyclic one where so much depande on intermediate yields.

It is important to confirm that liberation thinning produceo a worthwhile reopona~, in compariaon with a more severe ''blanket type" tr-eatment. Evid<lnce from Queens land indica toe tha.t it wl.ll aoo at a. considerably reduced cost. The thinning should aim to free the selected trees from crown com pet t t ion. Thio is p1-eoent ly incorporo. ted. into exparimento in Sara.wak, together with an attemrt to remove future ocm;etltim by compariaon with a tahle of minimum distances allowable between standing trees. This latter greatly increases tho coat above simple crown freedom criteria, and i~ hae still to provo its efficacy.

The alternative heavy treatment aiming for a response in the eeedlinP.'S should not 'be forgotten. I suspect that there are large areas that. carry a poor residual ata.nrl, either because of thA virpin condition or because of more complete log~ng ~r because of heavy logging dams.ge to the raaidun.la, tho.t should be managed under a longer rotation ao in the Nal83M Uniform System am which should receive auch heavy treatment. The principal of a.l taring the treatment to fit the ata..~ was di£Jcuased by lHoholaon ( 1972) for Q'-1.1eenola.nd comi tiona but it, can be adapted for o.ey foNot area.

7.4 Weut Malaysia

Tables 48 am 49 show my estimation of D.ipterocarp volume production based on the data presented. It ca~ be seen that it is low becauue of the lower stocking of residuals and does not become attractive until sixty years when seedling volume becomes available. Non-Dipterocarps it is true, will play a pa.rt anl booot volume, but they are an unknQwn

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factor and should not be relied on, except perhapa to the extent of their standing volume.

Until the value of the non-Dipterocarp component ie properly determined, the recommended cutting cycle must then be sixty yea.ra, and the remarks under para. 7.2 for Sabah will apply hP.re also. These were that in general more control over the logging is needed particularly marking for logging and retention. Table 1 shows that there is a relatively poor representation of Dipterocarps in the intermediate sizes before logging eo it is even more important here to preserve as many as possible. This also for the reason that reports from West Malaysia (Burgees 1970) indicate tha.t the M.U.s. cannot be relied on in these hill forests, ani so the great boost from the seedling generation in Table 49 may not be forthcoming. Apparently this failure of the M.u.s. is attributed to lack of seedlings and to high mortality in and after logging and these differences from conditions in Borneo and the Philippines are largely due to peculiarities of the two major species, Shorea curtisii and s. platycladoa {Burgees 1975). However, the same author shows that the worked areas in nine hill forest compartments had sufficient regeneration less than 5' tall on 6% of ·the area. 'l1ogether with the advance growth there is therefore sufficient co~I~.~Dercial stocki.nR to support a. silvicultural treatment. Whether this treatment is the M. u.s. or some variant such as underatorey cutting ( Burg€SS 1975) must be decided in West Malaysia on the results of experiment. The ewing away fro~ the M.u.s. or lack of faith in it was ver,y noticeable amonp,st most of the field and office staff I spoke with. However, I believe this is acting againBt good forestry in many areas. 'llfta hi 11 species mentioned above may requ1re different techniques (though I saw little if a.ey evidence 01 it) but man,y of the "lowland" species are common over much of the hi 11 foreote arrl are not being treated by any method at all. Ma~y of the staff believe that Dipteroc~rpn should not be opened up too severely and consequently very little effective treatment is baing done. For example, one ye.ar old enrichment pln.ntinga with S. loprosula were being "nursed" Wider dense shade and consequently the trees were hardly larger than when planted or were dead. '11hese may have been isolated cases but that they should occur in the ..:oWltry that pioneered Dipteroca.rp studies ani unravelled their ecological requirements, ia very saddening. It muot be I'Opea.ted tlw.t Dipteroca.rps require almost full light conditions for their best growth.

Beca.uoe of the present uncertainty with re~rd to treatment, ! believe it is ve·ry important that the prc-lop;gir.g sampling be as compreher1aive as possible, eo that ita data. can guide both felling and trea.t~ent regi~ea (see Nicholson 1972). For exaruple, it should record, in addition to species a.nd size, atem fonn and dominance for ·the advance grQwth of all acceptable apeciea. It abould also be flexible enough to record seedlings when these are necessary to make up the stocking. Then other data such aa climber, bartam, etc., infestation, are needed also. Felling can be regula ted on the ba.eif• of this oample, ao an to oxtroot a commercially viable volwr.~ but ati ll lerwE' an adequate reEidual stand or wiHm the conflict between theoe two factors cannot bP. resolved, whether the seodHng stand ic oufficient to regenerate the area after lOI?f"ing what io available. Dependant tm this dooision will be the type of treatment. Either a liberation thinning or a. heavier t!"6a.tment to stimulate the ooedlinm'!. 'liflio idea of' flexibility of cutting a.nd treatment regJ.mao io supported b,v Aooel ( 1977) who a~gests that cutting blocks of 200-300 hecta.rea be tho ba.ois for regulatiJH~ these a.apecto of Management.

7.5 Indonesia

Until better after lo~~ing stand tables ~hat cover tho varying forest conditions from Sumatra to Kalimantan, are derived recommendations cannot be specific, except that the I~oneaia.n selection system should be used whenever poonible. The same need for tighteni~ up control in the forest is evident ( Soerianegare. 1970). A prei"equiai te to this end ia the need of t1--ained staff to enforce the basically sound ma:w~ment eyetema allowed ( Doerboom ani Wierswn 1977). Aa just mentioned the Selection System ie preferred, but the provision of the choice of three systems is a recognition of the varying t~.fter loggi~ corditions. There do not appea.::- to be guide-lines laid down tc:; aid this choice. Soeria..negara. (1970) shows that a. pre-lo~ging assessment is a necessary part of the IDionaeia.n Selection System but I believe this assessment can also be used in t.f" .. • choice

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of systems to use. It is here suggested that if significant areas are found that do not meet the criteria laid down for the selection system, then they should be managed under the al tenw.te Modified Malayan Uniform system. However, it is believed that the criteria are set too higb, i.e. 25 trees/ha over .35 ems diameter. The selection system will still work well if 20 undamaged Dipterocarp trees per hectare over 20 ems di.ameter can be left, a.nd these lower standards are likely to be met more often. Such areas could be managed on a forty year cycle a.1nd should yield 2 m3jha., or more if treated (see below). Poorer stands should be managed on a. longer cycle and will take advantage of the boost to volumes provided by the seedling generation, as in the Modified Malayan Uniform System.

Treatment of logged areas has bean shown to increase growth a.nd this aspect needs to be investigated to the satisfaction of all local stnff. It is not presently specified in the Indonesian Selection System but ''Liberation 'rhinning" as being tented in Sarawak, shows every promise of being worth while. The Modified Malayan Uniform System incorporatee a treatment of all weed trees, to stimulate seedl1ng growth. Every effort must be made to do this on thea~ poorer areas, though the logistics and expense make it a huge task. As in the Philippines, enrichment with species such as Euca.lyQtus deglupta could be allowed with similar safeguards as mentioned there (Para. 7.15 ..

'Jlhere is too, a. caao for fast growittg ind.uatria.l planta.tl.ona (see fot· example Johnson and Dykstra 1978). The same discusoion ao in para 1.1 (4) applies to Indonesia also. With huge areaa of degraded land lying waste the scope for increasing timber production as well as proV1ding regular employment to shifting cultivntors, is enormous.

There is alrea.d,y a very large plantation programme Wlderwa.y ( Soedjarwo 1977) and thic is to be encouraged in every w~. Johnson & Dykstra believe that large industrial concerns can contribute very significantly to this progr.amme because of their expertise and existing inf'ra.atructure within concession areas. While this is an att1:acti ve proposition it must be followed with caution. Aa discussed in para 7.1 (4) the decision to plant should be taken on the corrli tion of the logged forest, and if actual aasessrDent shows this to be adequate for natural regeneration and growth, the temptation to destroy it in favour of plantations must be resisted. It is important to stress that assessment be made because it is all to easy for woodsmen even forester& to pass off regrowth areas as failures becauoe of thei~ disappointing appe3.rance from the outside. It is often a. different otory from the inside. It is strongly believed th.a.t most of the plantation effort should bo on waste land; estimated at 44 million hectares in 1975 (Oemi 1975 in Johnson & Dykstra 1978). Once such a. progra.m.me was started the population preaaure on the existing forest laooo, which cannot tolerate repeated disturbance, could be oignificantly reduced by drawing off tho people to profitable employment in previously empty a.reas. In certain areas, of courao, there \ollll be a cope fer plantations a.~ti Agro-foreot~·y clooe to exioting industrial plantc.

8. SUMMARY OF' HECOMNE?IDATION5

8.1 General

( 1} Effeati ve demarcation and protection from a.ll illegal OJ>flll'a.tions muot be given to p1'0ductive foreoto. ( pa.ge 48)

( 2} Set aside sufficient forest lam to meet the long term needs of the coWltcy, and rooiet ohort term development that does not ha.ve thio aim in view. ( pa.~ 48)

Theoo two basic recommendations are perhapa the moat difficult to put into practice am are outaide the scope of this paper. They a.re, however, vi tal to the continued production from the Mixed Dipteror.at"p foreeta. Their implementation requires input from a whole l~nRS of disciplinea - legislators, economists, eociologiato, land planners, agricul turiets, employment officers, hydrologiata, zoologists and others. These a.ll ohould interact with the forestry sector, for. the best overall solutions.

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( 3) In view of the dangers from short felling cycles, review the da.ta base for the 30 am 35 year cycles adopted in some areas. ( pa.ge 48)

(4) Similarly, investigate the danger of any genetic lose from accepting a 40 year cycle, even though growth data and economic yield ~ indicate it as quite suitable. ( page 48}

( 5) In all countr·ies, activities in the forest 1nust be more closely controlled with the understanding that the trees are a renewable resource, given on~ certain basic harvesting rules. The tendency to ''mine" the forest without reEI'Iord. to a. subsequent harvest mu.1t be C\vercome. (page 49)

8.2 The Philippin!!

(1) Continue with the Selective Logging Syst~m with present cutting limits as a general management system. All ac:tivities of the Bureau should bo r,eared to ensuring that every aspect of' the system is implemented in the forest, (and not abused as so often happens at present). (page 50)

(2) Institute well designed experiments to test the value of after logging treatments. (page 50)

(3) Allow full exploitation followed by enrichment planting with species ouch as Euc~~P.tus deglupta, immediately after logging, on certain areas with a poor residual stand. Logging damage on an area basis must be well controlled and Dipterocarp regener-ation must be allowed to remain with the planted species. (page 51)

(4) Conventional wcod producing plantations should be reatricted to waste land. Particularly not on land recently logged or that carries a. young stand of Dipteroca1~s. These plantations can be a useful aid in solving the kainginero problem in some areas and utilize the cogona.les in others. (page 51)

8.3 Saba.h

(1) For the first cutting cycle, at least, use a sixty year period. (page 52)

( 2) Introduce tree marking for felling and retention. (page 52)

( 3} Enforce botter lo.~<;ging practices by atrong action on the part of the ~st

( 4)

Department. (page 52)

Treat to free residuals from crown competition and to open up unbroken islands of forest to release the seedling population. (page 52)

8.4 Samwo.k

(1) A selective logging with a 40 year cycle is recommended as a general rule. (page 52)

{ 2) Sample before logging to determine the advance growth atand for marking for retention and to locate those areas (if any) that net"td management by a monocyclic method. ( page 53)

( 3) Introduce 'liberation thinnin~' aa a gene-ral practice in Mixed Dipterocarp forest, while refining the method in experim.ental areas. That is, do not wait for the perfect ayotem before applying what io known at present. (page 5.3)

- 57-

(4) Similarly on areas +.hat need seedling stocking introduce the heavier M.u.s. tJ~ of t rea. tr4ent. ( page 53)

8.5 West Malaysia

( 1) Initially introduce a sixty year cutting cycle. (page 53)

( 2) A comprehensive pre-logging sampling is needed to characterise the stands, so that either the volume cut can be adjusted eo as to leave an adequate residual stand or a decision to regenerate from seedlings can be made. ( pa.ge 54)

{ 3) Tree marking for felling and retention must be introduced and strictly enforced. (page 54)

( 4) Loggillg practicea also to be tightened up eo a.s to reduce damage. ( pa.ge 54)

( 5) Determir.e the value and silvicultural requirements of the non-Dipterocarp portion of the stand, so they can be brought into the yield calculations. (page 54)

( 6) Introduce libel'a.tion thinning to the residual stand and carry out regeneration treatment where this is needed. With regard to the latter some further experimentation is needed to show which areas can receive the normal M.u.s. treatment or where a variant is needed. '11he standa.rd treatment can be applied \o:i thout fear on areas wi thuut bertam and bamboo. (page 54)

8.6 Indonesia

(1)

( 2)

( 3)

( 4)

( 5)

( 6)

( 7)

In general, use the Indonesian Selection System with a 40 year rotation. (page 54)

The choice of this system must be supported by the data collected ;~ the pre-logging assessments (page 54~ These will usually indicate that a particular system is applicable on a regional basis. Finer pointe of control such aa determining the required residual stand, may need to be specified on smaller areas as in West Malaysia. (page 54)

All aspects of the system especially making of residualo and of forest trees ard their direction of fall am the after logging 1oo% inventory and residual sampling, should be strictly adhered to. (page 7-9 & 54)

'l'he requisite otaf'f must be tre.inad (page 54)

The Modified J61ayan Uniform System should be used where the residual stand will not support a harvest at 40 years, but where seedlings aro present or will be planted. The pre-loggifl8 aeaeosmente will provide these data. (page 55)

Experirner!tS confirming the w.lue of libero.tion thinning should be laid down. ( pa.ge 55)

Plantations (in the true sense) should be concentrated on waste la.ni( with careful investigation before they are allowed in concession areas. page 55)

-58-

:SmLIOORAPHY

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Aniel, s. Final report of FAO. Project MAL/75/012 19'78

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Anon. 1972

Ma.nua.l of silviculture for use in the productive forest estate, Sa.bah. Sa.ba.h Foroat Iecord No. 8. Kota. Kina.bulu, Sa.bah.

Barnard, R.c. Linear regene~tion sampling. Mal. For. XIII : 129-143. 1950

Boerboom, J.H.A. & Wiersum, K.F. The forestry situation in East Kalimantan. A report of 1977 Department of Tropical Silviculture, Agricultural university, Wa.geningen.

Brig:ha.ln, J .H. Logging and transport report FO:SF /PHI 16 Technical report 5. FAO, Romo. 1971

Brown, G.s. Note on recovery of lowland Dipteroca.rp forest from winch logging in North 1950 Borneo. Mal. For. XIII( 4) 23Q-231.

Brown, W .H. Vegetation of Philippine moWlta.ina. Bureau of printing, Manila.. 1919

Burgess, P.F. An approach towards a silvicultural system for the hill forests of the 1970 Na~ Peninsula. Mal. For. XXXIII(2) 126-133.

Burgess, P .F. S i 1 vicul ture in the hill fol'eata of the Ha.la.y Peninaula.. Foreat Research 1975 Irwtitute Kepon.g. Research Pamphlet No. 66.

Ca.ca.nindin, D.c., Micooa., L.s., Benyon, J.P. & Asile, E.S. Prediction function for the 1976 estimate of clea.n-out areao in selectively logged-over Dipterocarp forest.

Sylvatrop. Phil. For. Rea. J. 1(4) 297-302

Canonizardo, J .A. Yield production function for cut-over Dl.pterocarp sta.nde. Thesis 1976 submitted to University of the Pailippineo.

Co.nonizardo, J.A.. Personal communication. 1977

Chai, D.N.P. Enrichment planting in Sa.bah. Mal. For. 38( 4) 271-277. 1975

Chai, D.N.P. Peroona.l communication 1978

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Chai, D.N.P. & Udarbe, M.P. The effectiveness of current silvicultural practice in Sabah. 1977 Mal. For. 40( 1) 27-35

Decana.y, P. S i 1 vicul ture conditions on the cut-over areas of the Codwallader-Gibaon 1923 Lumber Co. in Batoon. Makiliug Echo Uo. 3.

Dawkins, H.c. The J'lldl1agement of natural tropical high forest with special reference to 1958 Uganda.. Imp. F,or. Institute. Paper No. 34.

Dawkins, H.c. The volume increment of natur.al tropical high-forest and the limitations of 1958( a) ita improvement. Paper second session of the Inter African Forestry Conference.

DeBacker, M. Member of Forestry Development Project, Sa.ra.wa.k. Personal communication. 1978

Durant, C.L. Further notes on the regeneration of the Heavy Dipteroca.rp Hardwoods. 1939 Malayan Forester VIII ( 3) 103-107.

Enda.cott, N.D. Derivation of a comm~rcial plantation programme for the Philippines to the 1977 year 2000, from Wood Supply/Dema.ni Projections. Review draft. FAO Technical

Report PHI/72/006.

FAO National forest inventory of West Malaysia 197D-1972. R~me.

1973

F1AO The timber species of the mixed Di.ptcrocarp forests of Sara.wak and their distribution. 1973(a) Fo~st Imustries Development Project. FO:D.P./MAL/72/009.

lt,AO A study of the forest operations of Syarikat Jengka during the fi.rat-year exploitation 1976 urrler sustained-.vield management. Forest management opera.t.ions research and

deve 1 opment, '11echni cal report 1 •

Fox, J.E.D. An enumeration of lowland lhpterocarp forest in Sabah. Mal. For. XXX( 4) 1967 263-279.

Fo"X, J .E.D. L~.-lgging damagt; and the influence of climber cutting prior to logging in the 1968 lowland D1pteroca.rp fore'=lt of Saba.h. Jilal. For. XXXI(4) 326-347.

Fox..J J.E.D. YieB plots repenerat1ng forest. Mal. For. XXXIII( 1) 7-41. 197V Fox, J.E.D. '11he natural vegetation of Sabah and natural regeneration of the Dipteroca.rp 1972 forests. Thesis submitted to University College of North Wales, Bangor.

Fyfe, A.J. Forestry in Sa.bah. &..lay. li1or. XXVII( 2) 82-95. 1964

Haeruma.n, H. Residual stand and its prospect for development in East Kalimantan .. 1978 Proceedings of symposium on the long-term effects of logging in South-east

Asi.o.. Page 115.

lkwzah, z. Some observations on the effects of mechanical logging on regeneration, soil 1978 and hydrological cordi tiona in East Kalimantan. Symposium on the long-tenn

effects of logging in South-east Asia. Page 73.

Higgins, N. Departmental report on sustained yield. Queensland Department of Forestry. 1977

Howroyd, c.s. & Albazo, J.c. Volume tables for standing timber. North Borneo forest 1954 records No. 4.. Govt. Printer Xota Kinabula, Sa.ba.h.

- 60-

Hutchinson, I.D. Study to establish interim guidelines for silviculture and forest 1977 management of the mixed Dipterocarp forest in Sarawak. Initial draft of

MAL/75/013, Rome.

Johnson, N.E. & Dykstra, G.F. Mairttaining forest production in East Ka.limantan, Indonesia. 1978 Eighth World Forestry Congress; Paper FID-I/18-4.

Koroleff, A. Silviculture in relation to logging. J. of Forestry, 36(10) 957-961. 1938

Laursen, u. Thinning of 1nixed Dipterocarp forest as a contribution to socio-economic 1976 development. Paper presented to 6th Malaysian Forestr,y Conference, Kuching.

Lee, H.s. Personal coaununication. 1978

Lee, H.s. & Lai, K.K. A manual of silviculture for the permanent forest estate of Sara.wak. 1977

Leibundgut, H. Developments in silviaultural syateme and their demands on operational 1976 methods. In Proc. XVI I.U.F.R.O. World Congress, Norway. PP• 5-15.

Leslie, A.J. Economic implications of the management systems applied to the tropical 1976 moist forests. Paper to Committee on Forest Development in the Tropics.

FAO, Rome.

Liew, T.C. Forest manipulation and regeneration in Sabah. I.B.P. Synthesis Meeting. 1974

Liew, T.C. & Juin, E. Natural vegetation east of Sook Plain. Sabah Society Journal. 1976

Liew, •r.c. & Wong Funf." On. Density, recruitment, mortality and growth of Dipterocarp 1973 seedlings in virgin and logged-over forests of Sabah. Mal. For. 36(1). 3-15.

MacKiJUlon, 197?

Behaviour and ecology of Orallg'-Utana. Animal Behaviour Vol. 22 No. 1.

Marcelo, M.B. & Tagudar, F~.T. Residual stands in selective hishlead logging. Phil. 1956 Jour. For. Vol. 12( 3-4).

Martyn, H.s. Wood harvesting, logging and transport in Sabah., Mal. For. XXIX( 4) 296-301. 1966

Meijer, W. Regeneration of tropical lowland forest in Sabah, Malaysia., fo1'ty years after 1970 logging. Mal. For. XXXIII( 3) 204-229.

Mendoza., V.B. & Semana, J.A. Giant Ipil-Ipil, cultural practices and growth rates in some 1977 Mindanao plantations. Sylvatrop. The Phil. For. Rea. Jour. Vol. 2(2) 39-44.

Nicholson, D. I. Gx-owth of forest trees in North Borneo. Unpublished Report. Forest 1957 Department Sabah.

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Nicholson, D. I. An a.nalysio of logging damage in tl'Opica.l rain i'oreat Uorth Borneo. 1958( a.) Na.l. For. XXI( 4) 235-245.

-61 -

Nicholson, D.I. Light requirements of Dipterocarp seedlings. lla.lc. For. XXIII( 4) 344-356. 1960

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-62-

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Walton, A.B. Soma consideration for the future management and ailvicultural treattnent of 1948 Malayan forests. Mal. For. XI( 1) 68-74.

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\vong, ~~.K. Poison Girdling under the Malayan Uniform System. Mal. For. XXIX( 2) 69-77. 1966

Wood, G.H.s. The Dipterocarp flowering season in North Borneo, 1955· Malayan Forester 1956 XIX(4). Page 193-201.

Wood, P.J. The development of tropical plru1tations anu the need for seed and genetic 1976 conservation. In tropir~l trees, variation, breeding and conservation.

Edited by Burley, J. & Styles, B.T. Academic Press.

Vannitn-e, B. Na.smgement possi'bl.li ties of tropical high forest in Africa.. !I'AO, Rome. 1975

Wyatt-smith, J. }~orest memot'ies of the Philippines. Mal. For. X'JII(3) 135-143. 1954

Wya.tt...Smi th, J. Development of a. si lvioul tural oyatem fo1· the conversion of natura.! inland. 1959 lowland evergreen rain forest of Jl.a.l.a.ya.. Malayan For. XXII( 2) 133-142.

Wyatt...Smith, J. Stems per acre ani Topogra.ph.y. Mal. For. XXIII( 1). 57-58. 1960

Wyatt-Smith, J. A note on the f1-eoh-wa.ter swamp, lowland and hill forest types of Na.lavra. 196~ Mal. For. XXIV(2) 110-121.

Wyatt..Smith, J. & Foenander, E.c. Dwua.ge to regenero.tion a.a a. result of logging. Na.l. 1962 For. XXV(1) 4D-44.

1) Starn after logging 2) Loggable volume 3) C.A.I. & Ra~io to

next cla.es 4) 10 Year Stand

(a) from previous class

(b) remaining in class

(c) TOTAL 5) 20 Year Stand

(a) from previous class

(b) remaining in class

(c) 'OOTAL 6) 30 Year Stand

( a.) from previ'.lus class

(b) ~ma.ining in class

{c) 'roTAL

(d) LOOGABLE VOLUME

7) 40 Year Stand {a) from previous

class ( b} reJM.ining in

cl&BS

(c) 'OOTAL

(d) LOGGABLE VOLUME

5-15 15-25

50 20

.39 .48

17 .6* 17 .6*

27.6+ 9.4

45-2 27.0

16.0* 16.0

24.9 12.7

40.9 28.7

14.4* 14.4

22.6 13.5

37.0 27.9

13.1* 13.0

20.4 13.1

33.5 26.1

MTIIDANAO YIELD PRGJECTION ** Diameter Class

25-35 35-45 45-55 I 55-65 65-75 75-85

10.4 I 9.3 7.3 5.1 2.9 3.1 5-9

.57 .67 .75 .85 .93 1.00

e.,, . 5·4 s.s s.o 3.9 2.4

4.0 2.9 1.6 .7 .2 -12,7 8.3 7 .. 1 s.1 4.1 2.4

(

11.? 6 .. 6 s.c 4.8 4.4 3.4

4.9 2.5 1.6 .8 .3 -16.6 9.1 6.6 5·6 4.7 3.4

12.4 8~6 5.4 4~5 4.3 3.9

6.4 2.8 1.5 .8 .3 -18.8 11.4 6.9 5.3 4.6 3.9

3.3 9.4 20.1

12.1 . 9.7 6.8 4.? 4.1 3.9 I

7.3 3.5 1.5 .1 .3 -19.4 I 13.2 8.3 s.4 4.4 3.9

3.3 9.0 20.1

** With 1~ Morta.li t.y ("" 90.4% after 10 years) 4 Recruitment

APPENDIX 1

85-95 95-105 10')-115 115-125

1.06 1.10 1.14 1.16 1

2.2

--2.2

3.1 1.9 .1

- - -3.1 1.9 .1

22.0 18.1 1.2

2.6 1.'7 ' 3.5 •

- - - -3.5 2.6 . 1. 7 • 3

24.9 24.7 l 21.1 4.1

+ Together these add to 45.2 or 90.~ of 50. The figure of 17.6 is derived as .39 x 50 x .904. Other figures are derived in the same way. See di·acuasion on page 68.

IDTAL

105 9.'

112.~

117 .e

120.1

14.

122 •

107.

2

2

e I

Advance Growth

Bar tam

C.F .I .•

Cogyn

Cogonal'lD

Cuttinl1 Cycle

Draglina

Giant Ipil-Ipil

Gutta Peroha

Haulba.ck

Kaingin

Ka.inginero

Kalan tao

Kapur

Neranti

Nerbau

M. u.s.

Nato -Ram in

Rod Luan

Raaidual

-64-

APPENDIX 2

Glossary of Tel_!le am Common lfwnes

In this paper used to indicate the stand of co121nercial trees below the cutting diameter, uaua.lly down to 10 em diameter.

A stemless palm; Eugeisoonia triotae

Continuous Forest Inventor.y.

A heavy hardwood; Dalanocarpuo heimii (Dipterocarpacaae)

A common graao of open land; Impara.tl!o cylindr:.i.ca. The Philippine equivalent of lalang in Malaysia.

Extenai ve areas supporting Cogon.

The period between oucceaaive harvests. (Compare rotation).

Main cable in a. high lead system ( • Mainline).

A particularly vigoroua strain of Leucaena leucoceuho.la. ( leguminonae).

A latex that can be hardened into a useful inoulating or moulding material. Largely aupereeded by modern plastics.

A light cable used to take the mainline am chokers back for the next load.

Tha Philippine tel~ for a temporar,y cultivation. (Usually illQga.l).

The culti·1ator (and his family) of a Kaingin.

A commercial tree, ~! calantas (Neliaceae).

An important commercial tree; Dryobalanops aroma.ti(;a ('£.!pte roc~aTpacea.e) •

~~e te•m given to the timbar of li~lt and medium weight Sho!"ea opp. ( uou.ally} in Went p.l,tJ.layoia and Sarawak. E.."~uivalent to Semya in Sabah and Philippines Na.hogany in the Philippines.

A commercial tree; Intsia biJu~. (Legwninooae)

Malayan Unifona Syatern.

A commercial tree; Pa.la.quium luzonienuis. (Sapota.ceac)

A oommercia.l tree; Gonystylue bancanus ( Th,yrnela.eaccae).

One of the species of Philippine Ha.hog&l\y' - sec Mera.nti.

An advance gl'OWth tree that surviveo a logging.

Rotation

- 65-

The pe:riod between release of seedlings by a lo'gging aOO. the loggir~g of those same seedlings when grown to trees. Th.a.t is, the period needed to grow a. ha.rvestable tree. (Compare cutting ~ycle).

A commercial tree that also produces Gutta Percha; Palaquium gutta f.• ~nuinum.