Fynbos, Fire and Ecology

Tony Marshall Programme Manager : ICM 21 July 2016

1. The Fire Paradox

USA - Global Fire Initiative Integrated Fire Management is an approach to managing both damaging and beneficial fires within the context of the natural environments and socio-economic systems in which they occur.

Damaging Fires • Fatalities and injuries – animals and people • Damage to Infrastructure and crops • Loss of biodiversity

Beneficial Fires • Reduction of fuel loads • Crop and grazing rejuvenation • Biodiversity rejuvenation

Fire – a bad master or a good servant ?

Europe – Fire Paradox Project

2. Fires - Occurrence

Natural vegetation fires are a natural and common part of the Western Cape Province environment and occur throughout the year.

CapeNature data of fire records for the past 18 years.

71

91

56

38

61 62

95

123

77 73

96

120

86

109 97

58

153 160

0

20

40

60

80

100

120

140

160

180

0.00

50 000.00

100 000.00

150 000.00

200 000.00

250 000.00

Total area burnt per financial year

Area burnt (ha) No of fires

• m

2. Fires

CapeNature records - Season of burn 2015-16

2. Fires - Season

20

4

1

3 4

20

12

18

22

33

13

10

0

5

10

15

20

25

30

35

-

10 000.0

20 000.0

30 000.0

40 000.0

50 000.0

60 000.0

70 000.0

80 000.0

90 000.0

100 000.0

Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 Jan-16 Feb-16 Mar-16

Fires - Fin year 2015/16

Area (ha) No of fires

CapeNature records - Causes of fires2015-16

2. Fires - Cause

Cause

Ave % last 11

Years 2015/16

Natural 20% 44 27%

Fire operations 9% 7 4%

Mechanical 8% 15 9%

People 27% 60 37%

Other 3% 3 2%

Unknown 20% 27 17%

NO DATA 13% 6 4%

100% 162 100%

CapeNature records - Causes of fires2015-16

2. Fires - Cause

Cause

Ave % last 11

Years 2015/16

Natural 20% 44 27%

Fire operations 9% 7 4%

Mechanical 8% 15 9%

People 27% 60 37%

Other 3% 3 2%

Unknown 20% 27 17%

NO DATA 13% 6 4%

100% 162 100%

3. Good or Bad ?

What determines whether a fire was good or bad ?

• Any fire that results in injuries or damage to infrastructure is bad.

• The objectives for the management of the land.

• From a Fynbos ecological viewpoint then T’s & C’s apply.

- Fynbos is adapted to fire and will burn under most conditions

- These conditions will determine how successful the Fynbos will rejuvenate

- The optimal conditions = the Fire Regime (T’s & C’s)

4. Fynbos Fire Regime

Ecologically good or bad ?

4.1 Fire Rotation

Fire Rotation – Vegetation age and frequency

Most of the long lived Fynbos plants are Serotinous – they retain their seeds in cones on the plant and only drop the seeds when the plant dies.

So :

Min intervals between fires:

- The time it takes for slowest maturing species to reproduce

- 50% of all individuals must have flowered at least 3 times

=> Will vary between reserves (vegetation types on a particular reserve) but in the region of 10 years old.

Max fire interval:

- More than half of the overstorey Proteas are dead =the veld is senescent (approximately 30yrs+)

5. Fire Rotation

Non-sprouting understorey shrubs

Bulbous species

Resprouting understorey species

Non-sprouting overstorey Proteoid shrubs

Long fire-intervals Short fire-intervals

4.2 Fire Season

Fire Season – Season of the year in which the vegetation burns

Most viable seeds are available in the cones by mid December.

Fynbos animals have adapted to summer fires by mostly breeding in winter

So :

Fynbos should only burn during the mid to late (December to April) summer months

4.2 Fire Season

Effect of fire season on regeneration of Protea species

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

60.0

0 1 2 3 4 5 6 7 8 9 10 11 12

Month of fire

Se

ed

ling

s p

er

pa

ren

t

P. eximia P:S

P.repens P:S

P.punctata P:S

Protea lorifolia P:S

Protea neriifolia P:S

Protea aurea P:S

4.2 Fire Intensity

Fire Intensity – How hot and clean does the vegetation burn

Optimal seed release and germination after a hot fire which has killed all the parent plants and opened up and prepared the seed bed.

So :

Fynbos should only burn during the mid to late (December to April) summer months.

4.3 Fire Intensity

Cool burn

Seed set

4.4 Fire Size

Fire Size – Extent of the area burnt

Can fauna (invertebrates, reptiles, birds, or slow maturing species (Clanwilliam cedar, etc) escape the fire in and utilize refuges.

Reseeding can also occur from the unburnt vegetation.

So :

Particularly for out of season and young veld the size of the fire must be limited to as small and area as possible.

As a rule of thumb for a given property :

- 33% young veld

- 33% medium age veld

- 33% old veld

4.4 Alien Vegetation presence

Alien Vegetation Presence or absence

Most invasive species are adapted to and are dependant on fires

Present = accelerated spread of invasive species

loss of species diversity

altered habitats

reduction in ecosystem service potential

excessively high burn intensity

soil structure alteration & erosion

So :

Clear the alien vegetation prior to a burn or have a plan to deal with the problem after the fire

4.4 Alien Vegetation Presence

Aca

cia

salig

na

No management

70 years 100 years

5. Conclusion

1. Fynbos requires fire as part of its rejuvenation strategy

2. Fires must take place :

1. When the vegetation is old enough

2. During the correct season

3. At the correct intensity

4. Be limited in size – particularly if out of season or if the vegetation is young.

5. Clear the alien vegetation

3. Then you will have had a Ecologically good fire.

Daunting but necessary

Thank you for the opportunity