A presentation by Subekti Rahayu, Meine van Noordwijk, Purwaningsih, Sonya Dewi and Degi Harja at ATBC on 12-16 July 2015.

1. RECOVERY OF LOWLAND TROPICAL
FOREST OF EAST KALIMANTAN THIRTY
YEARS AFTER MAJOR FIRE EPISODES
Subekti Rahayu, Meine van Noordwijk, Purwaningsih,
Sonya Dewi and Degi Harja
52nd Annual Meeting ATBC 2015
12-16 July 2015
Honolulu, Hawaii
Symposium 2
Integrated Landscape Management:
From Theory to Practice

2. BACKGROUND
• Specific effects of disturbance remain visible in
forest structure and species composition long after
a closed-canopy status is regained (Newbold et al.
2014; Winter 2012)
• Canopy structure and basal area recover in 56
years after selective logging (Priatna et al. 2004)
• Species richness recover in 150 years after clear
felling (Riswan et al. 1984)
• Aboveground biomass recovery was estimated to
take 80 years and biodiversity, assessed across
plant and faunal groups may take 120-150 years
(Martin et al. 2013)

3. • Published studies of long term forest recovery
after fire is limited due to limited long term
permanent plot observation established in
tropical forest of Indonesia; most studies
discussing impact of fire events on biodiversity
(van Nieuwstadt 2001; Slik 2002; Eichhorn 2006)
• Established permanent plot of 10.5 hectares area
in Samboja Research Forest, East Kalimantan by
Indonesian Institute of Sciences (IIS) in 1979 –
1981 is good chance to learn the forest recovery
process after fire
BACKGROUND

4. OBJECTIVES
• To understand the recovery process of species
composition after repeated fire events
• To understand the biomass recovery due to
repeated fire events
• To understand the implications on restoration

5. STUDY SITE
• Samboja Research Forest (SRF)
established 1978 in 504 ha
lowland dipterocarp forest and
expanded with another 3000
ha of logged-over forest 3000
ha in 1991.
• Currently, 504 ha covered by
forest (undisturbed and
disturbed by fires) and 3000 ha
of shrubs and grasslands.
• Since 2011, SRF is managed by
BALITEK KSDA, FORDA,
Ministry of Forestry, now
Ministry of Environment and
Forestry

6. Fire histories and Inventories
• 10.5 hectares permanent plot in lowland mixed
dipterocarp of SRF established and observed by IIS 1979-
1981 (row 1-70), published by Kartawinata et al. (2008)
• Row 1-63 affected by two major fire events in 1983 and
1998
• Row 21-31 (1.65 ha) revisited by IIS, published by
Simbolon (2005)
• Row 21-32 (1.8 ha) revisited in 2011 by IIS and ICRAF
Unburned
forest
2011
observation
1979-1981 observation
1 70
Column: 700 m
Row:
150 m
21 32 63

7. METHODS
• 2011 survey:
– 10 m x 10 m sub-plot set up
in row 21-32
– all tree above 10 cm DBH
were recorded
– stem diameter and tree
height were measured
– tree position was mapped at
sub-plot level
– leave samples were collected
and identified

8. METHODS
• Data analysis
– Comparing tree population based on diameter
classes to 1979-1981 for row 21-32
– Aboveground biomass estimation with four
allometry equations (Chave et al. 2005; Ketterings
et al. 2001; Basuki et al. 2009; Brown 1987)
– Constructed species accumulation curve with
bootstrapping techniques on the 10 m x 10 m sub-
plot data

9. ALLOMETRY EQUATIONS
• Chave et al. (2005)
– B =  exp(-1.499+2.148ln(D)+0.207(ln(D)2) -
0.0281(ln(D)3)
• Ketterings et al. (2001)
– B = 0.11D2.62
• Basuki et al. (2009)
– ln(B) = -0.744+2.188ln(D)+0.832ln(D)
• Brown (1987)
– B = 0.118D2.53
Where: B = biomass (kg tree-1);  = wood density (g
cm-3); D = diameter at breast height (1.3 m) (cm).

10. RESULTS
Recruited after second
fire
Shade tolerant
recruited after first fire;
light demanding
recruited after second
fire
Recruited after first
fire
Survived from first
and second fire:
Dipterocarpus cornutus,
Eusideroxylon zwageri;
Diospyros borneensis,
Polidocarpus majadun

11. 30%
Ketterings’ and Brown’s allometry equations are similar, except
that Ketterings’ includes wood density, which results in 20% lower
estimation than Brown’s
After fire, biomass
of bigger tree >60
cm DBH
dramatically
decrease

12. • 95% of tree populations are of lower
wood density species after fire compared
those before fire
• 60% of them significantly lower up to 0.2
point different that contributed by light
demanding “pioneer” species
• the remaining 5% are similar in wood density

13. Macaranga sp. is dominant
canopy cover in naturally
regeneration 30 years after
initial fire
Performance of disturbed
forest in SRF

14. 1979-1981 survey: 552 species in 10.5
hectares (Kartawinata et al. 2008)
Number of species increases
dramatically up to 200 sites and at
slower rate for larger number of sites

15. RESULTS for 1.8 ha inventories
1979-1981 survey: 254 species
2011 survey: 192 species
Natural regeneration during 30 years after
initial fire has not led to full species
recovery regarding the species richness

16. CONCLUSIONS
• Thirty years after a major fire:
– Tree population 100% recovered; proportion of tree 10-20
cm DBH increase about 10%, but the bigger tree decrease
– Aboveground biomass 60% recovered, but bigger tree
above 60 cm DBH contribution still reach 30%
– Species richness 75% recovered at 1.8 ha, but for larger
area can be lower
– Tree population dominated by light demanding species
that contain lower wood density
• Implication to conservation measures:
– Natural regeneration is possible after fire disturbance, but
recovery relies on seed availability from the surrounding
areas
– Ecological restoration is needed, especially when the
landscape is patchy such as the case in SRF

17. THANK YOU