Greenhouse gas emissions from tropical peatlands of Kalimantan,Indonesia

Abstract

Greenhouse gas emissions were measured from tropical peatlands of Kalimantan, Indonesia. The effect of hydrological zone and land-use on the emission of N 2 O, CH 4 and CO 2 were examined. Temporal and annual N 2 O, CH 4 and CO 2 were then measured. The results showed that the emissions of these gases were strongly affected by landuse and hydrological zone. The emissions exhibited seasonal changes. Annual emission of N 2 O was the highest (nearly 1.4 g N m −2 y −1 ) from site A-1 (secondary forest), while there was no significant difference in annual N 2 O emission from site A-2 (paddy field) and site A-3 (rice-soybean rotation field). Multiplying the areas of forest and non-forest in Kalimantan with the emission of N 2 O from corresponding land-uses, the annual N 2 O emissions from peat forest and peat non-forest of Kalimantan were estimated as 0.046 and 0.004 Tg N y −1 , respectively. The emissions of CH 4 from paddy field and non-paddy field were estimated similarly as 0.14 and 0.21 Tg C y −1 , respectively. Total annual CO 2 emission was estimated to be 182 Tg C y −1 . Peatlands of Kalimantan, Indonesia, contributed less than 0.3% of the total global N 2 O, CO 2 or CH 4 emission, indicating that the gaseous losses of soil N and C from the study area to the atmosphere were small.

Biogeochemical processes along a nutrient gradient in a tropical ombrotrophic peatland

“…Methane fluxes measured here were several orders of magnitude lower than CO 2 fluxes and varied markedly among sites. The highest CH 4 fluxes from site 1 (R. taedigera) and site 5 (sawgrass swamp) are comparable to fluxes reported in the literature from Kalimantan(e.g., 0.35-2 mg CH 4 m -2 h 1 ; Furukawa et al 2005;Hadi et al 2005;Jauhiainen et al 2005), while the lowest CH 4 fluxes at the three intermediate sites in the current study (C. panamensis and mixed forest) are comparable to those reported for Sarawak wetlands (maximum rates of 11.2 lg CO 2 m -2 h -1 ; Melling et al 2005a, b). Our results suggest that CH 4 fluxes have high spatial variability in peatland systems and vary in response to differences in the water table Hadi et al 2005;Jauhiainen et al 2005) and substrate availability (Bachoon and Jones 1992) to a greater extent than CO 2 fluxes.…”

“…As warming and drainage during the laboratory incubation increased CO 2 production from surface peat by an order of magnitude compared to field fluxes, this demonstrates that the carbon storage potential of the system may be sensitive to climate warming and/or a lowering of the water table (Brady 1997;Inubushi et al 2005;Hadi et al 2005;Jauhiainen et al 2005). However, this may be regulated to some extent by the apparent strong nutrient limitation of below-ground processes in the peatland interior, as found in subtropical wetlands (Bachoon and Jones 1992;Battle and Golladay 2007;Wright et al 2009).…”

“…Seasonal variability in gas fluxes has been shown in tropical peatlands (e.g. Hadi et al 2005) and it is likely that both the CH 4 and CO 2 fluxes in the San San Pond Sak wetland will fluctuate between the drier and wetter periods of the year. Further detailed studies at a range of temporal scales are therefore required to assess the temporal stability of the spatial differences in gas fluxes in the peatland shown here as well as the mechanisms driving them.…”

Opportunities for reducing greenhouse gas emissions in tropical peatlands

“…Subsidence increases with depth up to 50 cm below the surface, after which it remains constant (34). In addition to the CO 2 emissions, these changes affect CH 4 and N 2 O fluxes (35). Because most of these peat systems are ombrotrophic, and thus tend to be nutrient-limited, nutrient additions are likely to significantly increase both oxidation of soil organic matter, leading to increased CO 2 emissions, and N 2 O emissions in the case of N fertilizer.…”

The impacts and opportunities of oil palm in Southeast Asia: What do we know and what do we need to know?

“…(Source: after Fargione et al 2008) and other greenhouse gases affect the atmosphere and climate (Mosier et al 2004). Provisional data suggest that such emissions from Kalimantan's peatlands are low (Hadi et al 2005). The impacts of oil palm plantations on non-CO 2 greenhouse gas emissions, the costs, benefits and possible improvements are still unclear.…”