ECOLOGICAL RESTORATION OF NATIVE FOREST IN THE … · ECOLOGICAL RESTORATION OF NATIVE FOREST IN...
1
ECOLOGICAL RESTORATION OF NATIVE FOREST IN THE COASTAL RANGE OF SOUTHERN CHILE. AN EXPERIMENT OVER 18 YEARS Valdivian forest and how it has been transformed The Valdivian forest of southern Chile, the forests of the north-west Pacific coast in USA and the forests of New Zealand are the world's only cool-temperate rain forests. During the 19th century, the Coastal Range of southern Chile between the Biobío River and Puerto Montt was covered by dense forest. Vast areas of forest were burnt during the 19th century, and subsequently the remaining forest was impoverished by selective felling for commercial extraction, leading to the existence of large areas of secondary and degraded forests. Exploitation and destruction of the remaining forest intensified from the 1950s. Institutional context – local and national CEA has run a Rural Development programme in the Valdivia River estuary since 1986, and subsequently a Biodiversity programme. CEA had previously developed projects to study evaluation of the landscape as a resource, the viability of forest nurseries applying phytosociological techniques in the area and training for adults. The proposal is consistent with the local context, i.e. the main guidelines for the Corral district, which has defined tourism and aquaculture as priority development areas. It will help to restore landscapes to expand tourism services in the area, which offers great potential. Nationally it will contribute to the implementation of international agreements. Defining the problem, hypothesis and proposed solution The coastal Valdivian forest has receded severely, giving place to secondary scrub. On soils degraded by over-grazing, this is dominated by Ulex or monoculture of P. radiata. Natural restoration is impossible, implying: a) loss of biodiversity, due to the exclusion of native vegetation and invasion by exotic species and wildlife habitat loss; b) loss of landscape as a resource; c) reduction of natural water resources; d) severe firewood deficit for the rural population. The main local causes of these problems are: a) the advance of the agriculture frontier in the 19th century (1850-1900); b) the use of native forest in the district as a source of firewood to supply a local steel industry (1920-1950); c) the replacement of native forest by P. radiata (1960-date); d) the use of firewood for domestic consumption (1850-date); and e) forest fires (1950-date). Our hypothesis is that restoration of the Valdivian forest by phytosociological methods, with community support, environmental education, the planting of copses with high energy species and fire prevention actions, could improve the quality of the environment, restore water bodies, improve the landscape for tourism, increase biodiversity and overcome the firewood shortage. The proposed solution was: a) restore areas degraded by Ulex; b) create community associations (nursery owners, fire brigade and school clubs); and c) to plant dendroenergetic species in order to satisfy firewood demand while reducing pressure on remaining native vegetation. Recolonisation by wildlife At the start of the restoration we measured the diversity of mammals, birds and herpetofauna in the Ulex scrub which covered the majority of the area for intervention. Ten years later (2007) we studied the recolonisation by wild fauna. The bird diversity in the restored habitat was greater than in other environments on Isla del Rey. We are currently assessing recolonisation after 18 years (2014) and the results are very promising. To accelerate habitat restoration for fauna, we improved habitat conditions by installing nesting-boxes for raptors and Passeriformes. Also devices which recreate micro- habitat conditions for amphibians, achieving increases in diversity and abundance in these managed habitat areas. Acknowledgements: Proyect “Restauración del Bosque Valdiviano Costero” (United Nations Program for Development UNDP) and Fondo de las Américas. Municipalidad of Corral and especially numerous volunteers who help with field measurements. Study area The area of the island is 5,103.2 ha, half of which is covered by forestry plantations of P. radiata and Eucalyptus spp. (2,564 ha), and a quarter by degraded native vegetation (1,303 ha). Scrub covers 526.2 ha, while only 428.7 ha (8.4 %) are fields for arable farming or livestock grazing. Geographical location of the plots studied Ulex europaeus Plant establishment, mortality and growth Growth and mortality of plants was evaluated in a sample of marked trees. Species with the highest establishment rates were tepa and ulmo, while the lowest were coihue and laurel. The highest average annual mortality was recorded in the first year of monitoring (5.6%); it decreased significantly after 2003 (0.2%). In the first six years the highest mortality rates were in ulmo (5.8%) and roble (5.5%); they were low in other species (< 1% per year). Mortality was very low after 2003 (< 0.1% per year). Growth was assessed by height, breadth or crown cover, and trunk diameter. The highest growth rates in these three parameters were recorded in coihue, avellano and roble. The dynamic of coihue and ulmo forest degradation, regeneration and restoration (modelled by Ramírez 1982). Area selection and phytosociology As indicated by the National Research Council (1992), we established the limit to show that self-regeneration of the system where the restoration was to be carried out was impossible. In Isla del Rey, these areas were covered by U. europaeus. A land-use map was drawn up with information from the native forest survey, and using GIS to re-classify the land covers. Ulex-covered areas were selected. Average height variation (cm) of live plants recorded in the Altamira plot 1998-2014 Top right: Environmental education, forest brigade. Left and bottom right: Devices for fauna in restored forest. Innovative elements and achievements The project has developed three innovative elements: a) a conceptual model for restoring Valdivian forest; this is the first experiment in Chile, and one of the few in Latin America, to reconstruct the forest based on phytosociological criteria, i.e. using silviculture techniques to restore the original forest; b) a conceptual model for forest fire prevention, based on the creation of community fire brigades; c) a method for controlling gorse. Recovery of the original plant cover, especially the coihue and ulmo association, acts as an efficient controller of this pest. Original plant cover, nursery production and silviculture techniques The presence of at least three forest communities was established: a) olivillo forest (Lapagerio-Aextoxiconetum punctatii); b) coihue and ulmo forest (Nothofago- Eucryphietum cordifoliae); c) roble-laurel and lingue forest (Nothofago-Perseetum linguae). Based on the phytosociological information, plant reproduction began in the greenhouse for nursery production of pioneer species which were then planted (e.g. Nothofagus dombeyi, N. obliqua, Eucryphia cordifolia, Laurelia sempervirens, Laureliopsis philippiana, Drimys winteri, Gevuina avellana and Aextoxicon punctatum, in varying proportions in the different plots. Planting was carried out in the winters of 1996-1997 in 12 plots on Isla del Rey. Regeneration of the original forest If human impact diminishes, these disturbed associations give rise to secondary scrub which allows the original community to regenerate. However, if the pressure continues, with increasing destruction and soil degradation, in most cases regeneration of the original forest becomes impossible. If there is no further intervention after this forest is felled, the original forest community can regenerate; however if a high level of human intervention is maintained, in the form of sheep grazing, the soil becomes exhausted, and when abandoned it is colonised by Ulex europaeus. Alternatively it is used for plantations of Pinus radiata. In either case regeneration of the original forest is impossible (Fig. 1). Principal results a) A nursery was set up on Isla del Rey which produced 48,000 plants; 28.5 ha were restored according to phytosociological criteria; b) small landowners received a total of 12.4 ha planted with copses of high energy species for firewood; c) a suitably equipped forest fire brigade was created and trained to prevent and fight fires; d) Ulex europaeus grew until the canopy of planted species closed; d) an environment and native forest education programme was developed; (e) the beneficiaries were trained in nursery and restoration practices; (f) the restoration was monitored – it has now been running for 18 years. 0 200 400 600 800 1000 1200 Average height (cm) Year Coihue Roble Ulmo Laurel Tepa Canelo Avellano Olivillo Average crown cover(cm) of live plants recorded in the Altamira plot 1998- 2010 Average trunk diameter variation (cm) of live plants recorded in the Altamira plot 1998-2014 0 50 100 150 200 250 300 350 400 Average crown cover (cm) Year Coihue Roble Ulmo Laurel Tepa Canelo Avellano Olivillo 0 5 10 15 20 25 Average trunk diameter (cm) Year Coihue Roble Ulmo Laurel Tepa Canelo Avellano Olivillo
Transcript of ECOLOGICAL RESTORATION OF NATIVE FOREST IN THE … · ECOLOGICAL RESTORATION OF NATIVE FOREST IN...
ECOLOGICAL RESTORATION OF NATIVE FOREST IN THE COASTAL
RANGE OF SOUTHERN CHILE. AN EXPERIMENT OVER 18 YEARS
Valdivian forest and how it has been transformed
The Valdivian forest of southern Chile, the forests of the north-west Pacific coast in USA and
the forests of New Zealand are the world's only cool-temperate rain forests. During the 19th
century, the Coastal Range of southern Chile between the Biobío River and Puerto Montt
was covered by dense forest. Vast areas of forest were burnt during the 19th century, and
subsequently the remaining forest was impoverished by selective felling for commercial
extraction, leading to the existence of large areas of secondary and degraded forests.
Exploitation and destruction of the remaining forest intensified from the 1950s.
Institutional context – local and national
CEA has run a Rural Development programme in the Valdivia River estuary since 1986, and subsequently a Biodiversity programme. CEA had previously developed projects to study evaluation of the landscape as a resource, the viability of forest nurseries applying phytosociological techniques in the area and training for adults. The proposal is consistent with the local context, i.e. the main guidelines for the Corral district, which has defined tourism and aquaculture as priority development areas. It will help to restore landscapes to expand tourism services in the area, which offers great potential. Nationally it will contribute to the implementation of international agreements.
Defining the problem, hypothesis and proposed solution
The coastal Valdivian forest has receded severely, giving place to secondary scrub. On soils degraded by over-grazing, this is dominated by Ulex or monoculture of P. radiata. Natural restoration is impossible, implying: a) loss of biodiversity, due to the exclusion of native vegetation and invasion by exotic species and wildlife habitat loss; b) loss of landscape as a resource; c) reduction of natural water resources; d) severe firewood deficit for the rural population. The main local causes of these problems are: a) the advance of the agriculture frontier in the 19th century (1850-1900); b) the use of native forest in the district as a source of firewood to supply a local steel industry (1920-1950); c) the replacement of native forest by P. radiata (1960-date); d) the use of firewood for domestic consumption (1850-date); and e) forest fires (1950-date). Our hypothesis is that restoration of the Valdivian forest by phytosociological methods, with community support, environmental education, the planting of copses with high energy species and fire prevention actions, could improve the quality of the environment, restore water bodies, improve the landscape for tourism, increase biodiversity and overcome the firewood shortage. The proposed solution was: a) restore areas degraded by Ulex; b) create community associations (nursery owners, fire brigade and school clubs); and c) to plant dendroenergetic species in order to satisfy firewood demand while reducing pressure on remaining native vegetation.
Recolonisation by wildlife
At the start of the restoration we measured the diversity of mammals, birds and herpetofauna in the Ulex scrub which covered the majority of the area for intervention. Ten years later (2007) we studied the recolonisation by wild fauna. The bird diversity in the restored habitat was greater than in other environments on Isla del Rey. We are currently assessing recolonisation after 18 years (2014) and the results are very promising. To accelerate habitat restoration for fauna, we improved habitat conditions by installing nesting-boxes for raptors and Passeriformes. Also devices which recreate micro-habitat conditions for amphibians, achieving increases in diversity and abundance in these managed habitat areas.
Acknowledgements: Proyect “Restauración del Bosque Valdiviano Costero” (United Nations Program for Development UNDP) and Fondo de las Américas. Municipalidad of Corral and especially numerous volunteers who help with field measurements.
Study area
The area of the island is 5,103.2 ha, half of which is covered by forestry plantations of P. radiata and Eucalyptus spp. (2,564 ha), and a quarter by degraded native vegetation (1,303 ha). Scrub covers 526.2 ha, while only 428.7 ha (8.4 %) are fields for arable farming or livestock grazing.
Geographical location of the plots studied
Ulex europaeus
Plant establishment, mortality and growth
Growth and mortality of plants was evaluated in a sample of marked trees. Species with the highest establishment rates were tepa and ulmo, while the lowest were coihue and laurel. The highest average annual mortality was recorded in the first year of monitoring (5.6%); it decreased significantly after 2003 (0.2%). In the first six years the highest mortality rates were in ulmo (5.8%) and roble (5.5%); they were low in other species (< 1% per year). Mortality was very low after 2003 (< 0.1% per year). Growth was assessed by height, breadth or crown cover, and trunk diameter. The highest growth rates in these three parameters were recorded in coihue, avellano and roble.
The dynamic of coihue and ulmo forest degradation, regeneration and restoration
(modelled by Ramírez 1982).
Area selection and phytosociology
As indicated by the National Research Council (1992), we established the limit to show that self-regeneration of the system where the restoration was to be carried out was impossible. In Isla del Rey, these areas were covered by U. europaeus. A land-use map was drawn up with information from the native forest survey, and using GIS to re-classify the land covers. Ulex-covered areas were selected.
Average height variation (cm) of live plants recorded in the Altamira plot
1998-2014
Top right: Environmental education, forest brigade.
Left and bottom right: Devices for fauna in restored forest.
Innovative elements and achievements
The project has developed three innovative elements: a) a conceptual model for restoring Valdivian forest; this is the first experiment in Chile, and one of the few in Latin America, to reconstruct the forest based on phytosociological criteria, i.e. using silviculture techniques to restore the original forest; b) a conceptual model for forest fire prevention, based on the creation of community fire brigades; c) a method for controlling gorse. Recovery of the original plant cover, especially the coihue and ulmo association, acts as an efficient controller of this pest.
Original plant cover, nursery production and silviculture techniques
The presence of at least three forest communities was established: a) olivillo forest (Lapagerio-Aextoxiconetum punctatii); b) coihue and ulmo forest (Nothofago-Eucryphietum cordifoliae); c) roble-laurel and lingue forest (Nothofago-Perseetum linguae). Based on the phytosociological information, plant reproduction began in the greenhouse for nursery production of pioneer species which were then planted (e.g. Nothofagus dombeyi, N. obliqua, Eucryphia cordifolia, Laurelia sempervirens, Laureliopsis philippiana, Drimys winteri, Gevuina avellana and Aextoxicon punctatum, in varying proportions in the different plots. Planting was carried out in the winters of 1996-1997 in 12 plots on Isla del Rey.
Regeneration of the original forest
If human impact diminishes, these disturbed associations give rise to secondary scrub which allows the original community to regenerate. However, if the pressure continues, with increasing destruction and soil degradation, in most cases regeneration of the original forest becomes impossible. If there is no further intervention after this forest is felled, the original forest community can regenerate; however if a high level of human intervention is maintained, in the form of sheep grazing, the soil becomes exhausted, and when abandoned it is colonised by Ulex europaeus. Alternatively it is used for plantations of Pinus radiata. In either case regeneration of the original forest is impossible (Fig. 1).
Principal results
a) A nursery was set up on Isla del Rey which produced 48,000 plants; 28.5 ha were restored according to phytosociological criteria; b) small landowners received a total of 12.4 ha planted with copses of high energy species for firewood; c) a suitably equipped forest fire brigade was created and trained to prevent and fight fires; d) Ulex europaeus grew until the canopy of planted species closed; d) an environment and native forest education programme was developed; (e) the beneficiaries were trained in nursery and restoration practices; (f) the restoration was monitored – it has now been running for 18 years.
0
200
400
600
800
1000
1200
Ave
rag
e h
eig
ht (c
m)
Year
Coihue
Roble
Ulmo
Laurel
Tepa
Canelo
Avellano
Olivillo
Average crown cover(cm) of live plants recorded in the Altamira plot 1998-
2010
Average trunk diameter variation (cm) of live plants recorded in the Altamira
plot 1998-2014
0
50
100
150
200
250
300
350
400
Ave
rag
e c
row
n c
ove
r (c
m)
Year
Coihue
Roble
Ulmo
Laurel
Tepa
Canelo
Avellano
Olivillo
0
5
10
15
20
25
Ave
rag
e tru
nk d
iam
ete
r (c
m)
Year
Coihue
Roble
Ulmo
Laurel
Tepa
Canelo
Avellano
Olivillo
