INCAS Program ESTIMATING ABOVEGROUND CARBON STOCK CHANGES IN PEAT SWAMP FOREST 1,2 Haruni Krisnawati, 1 Wahyu Catur Adinugroho, 1 Rinaldi Imanuddin, 2 Silver Hutabarat 1 Forestry Research and Development Agency (FORDA), Jl. Gunung Batu No 5 Bogor, Indonesia 2 INCAS-IAFCP, Gd. Manggala Wanabhakti, Jakarta, Indonesia
Under the Indonesian National Carbon Accounting System (INCAS) Program, the Indonesia-Australia Forest Carbon Partnership (IAFCP) is providing funding and technical support to build Indonesia’s capacity to develop and operate a sovereign national level forest carbon accounting system. In doing so, the INCAS Program is developing a pilot forest carbon accounting system to support the Government of Indonesia’s future national MRV Institution. Estimating the biomass content in Indonesia’s forests is one of the key inputs to quantifying carbon emissions from forest activities.
Methods
24
Stand Structure
We found 80 tree species, 55 genera and 30 families in all plots with the range of wood density was 0.39-1.04 kg/m3. The average basal area and the number of surviving trees are presented in Figure 1. The average annual diameter increment of the trees were 0.33-0.47 cm.
Figure 1. The average basal area and the number of surviving trees for 5 years from sixteen PSPs
680
23.5
660
23
640
22.5
620
22
600
21.5
580
21
1995
The biomass value of each tree in the plots was calculated based on the allometric model developed for logged-over peat swamp forest in Sumatra (AGB = 0.206284 Dbh2.4511, R-sq = 0.96), in which 50 percent of the biomass was considered to be carbon stock. Location of Permanent Sample Plots (PSPs) in Jambi Province, Indonesia
Overall, the aboveground C-stock of all species in the plots increased from the initial value. The increases may be attributed to the high rate of recruitment and growth of some species.
The positive value means there was an addition in aboveground C-stock due to recruitment and growth. The negative value means there was a loss of biomass due to mortality.
PSP
Conclusion Aboveground carbon stock in peat swamp forest is dynamic. The relationship model between aboveground (c-stock) and its increment could be used to estimate carbon stock changes in the study site by calculating the product of the aboveground C-stock increment per hectare and forest area. This information will be an input to the Indonesian National Carbon Accounting System (INCAS), particularly for peatland forests.
Indonesia-Australia Forest Carbon Partnership
Figure 4 shows the relationship between the aboveground C-stock and the annual aboveground C-stock increment obtained from the sixteen PSPs. There was a significant logarithmic relationship (P < 0.01) between the aboveground C-stock and its annual increment. The determination coefficient of the logarithmic relationship was relatively high (R2 = 0.81).
2000
560
1995-1996
1995-1996
1995-1996
1995-1996
1995-1996
6.55 2.67 0.23 5.21 7.38 3.50 5.10 4.04 6.18 2.91 2.28 1.14 3.22 2.75 3.97 -16.88 2.52
-11.89 -1.22 3.79 3.55 6.68 3.82 -3.24 -2.06 -3.82 9.17 4.47 1.95 -13.91 2.98 0.82 3.00 0.26
4.18 6.67 6.74 10.31 3.96 4.87 6.80 7.71 6.30 2.67 3.16 4.02 4.13 5.00 2.81 5.29
3.38 5.54 5.94 9.18 3.09 5.33 7.02 7.61 6.48 3.11 3.12 4.88 3.81 5.45 2.87 5.12
4.64 6.12 6.83 -1.62 4.58 6.08 8.21 7.99 7.64 -3.38 3.67 4.86 3.84 5.58 3.73 4.58
-2.67 2.73 4.47 5.65 6.39 3.79 3.63 4.80 5.14 6.50 1.83 2.61 0.61 3.50 4.16 -0.89 3.27
Figure 3. Aboveground C-stock estimates for 5 years from sixteen PSPs
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PSP 1 PSP 2 PSP 3 PSP 4 PSP 5 PSP 6 PSP 7 PSP 8 PSP 9 PSP 10 PSP 11 PSP 12 PSP 13 PSP 14 PSP 15 PSP 16
250 200 150 100 50 0 1995
1996
1997
1998
1999
2000
Year of Measurement
Aboveground C-stock Increments (Mg C ha-1 yr-1)
Figure 1. Location of the study site
1999
1995-1996
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Average
The average aboveground C-stock increment between two successive measurements was 3.27 Mg C ha-1 yr-1.
Relationships between carbon stock and its increment
1998
Aboveground C-stock change (Mg C ha-1 yr-1)
C-stock changes
The changes of aboveground C-stock for five years from sixteen PSPs are presented in Figure 3.
1997
Figure 2. Aboveground C-stock estimates for 5 years from sixteen PSPs
Above ground (Mg C ha-1)
Inventory data collected from sixteen Permanent Sample Plots (PSPs) (100 m x 100 m each) (Figure 1) which have been selectively logged and measured annually for six years (1995, 1996, 1997, 1998, 1999 and 2000) were used to estimate the changes of aboveground biomass and carbon stock of the peat swamp forests. All woody plants of at least 10 cm Dbh (Diameter at breast height) were identified for species and measured for both Dbh and height. The dead and newly recruited trees were recorded at each measurement time.
1996
Year of Measurement
Aboveground C-stock estimates
The estimates of aboveground C-stocks of the sixteen PSPs vary from 79.58 to 235.72 Mg C ha-1 (average = 140.87 Mg C ha-1) in 1995 and from 92.88 to 261.40 Mg C ha-1 (average = 152.98 Mg C ha-1) in 2000 (Figure 2).
700
N trees 10 cm up (ha-1)
Many studies on aboveground living biomass and carbon stock in tropical forests have been carried out, either measured directly based on destructive sampling in experimental plots or estimated based on forest inventory data. However, most of these studies focused on the estimation of forest biomass and carbon stock at one occasion. Forest biomass and carbon stock may be dynamic and changes occur continuously throughout time due to loss of carbon during deforestation and forest degradation as well as accumulation of carbon during forest re-growth. This study aimed to estimate the changes of aboveground carbon stock in peat swamp forests using forest inventory data from permanent sample plots in Jambi, Indonesia.
Results Basal Area (m2 ha-1)
Introduction
BAPPENAS
Figure 4. The relationship between annual aboveground C-stock increment and aboveground C-stock 9 8
SBI = 4.0494ln(B) - 15.463 R2 = 0.8049
7 6 5 4 3 2 1 0
0
50
100
150
200
Aboveground C-stock (Mg C ha-1)
250
300