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Carbon dioxide emissions from an Acacia plantation on peatland in Sumatra, Indonesia.
- Source :
- Biogeosciences Discussions; 2011, Vol. 8 Issue 4, p8269-8302, 34p
- Publication Year :
- 2011
-
Abstract
- Peat surface CO<subscript>2</subscript> emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m) in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations. The autotrophic root respiration component of the CO<subscript>2</subscript> emission was separated from heterotrophic emissions caused by peat oxidation in three ways: (i) by comparing CO<subscript>2</subscript> emissions within and beyond the tree rooting zone, (ii) by comparing CO<subscript>2</subscript> emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone), and (iii) by comparing CO<subscript>2</subscript> emissions before and after Acacia tree harvesting. On average, the contribution of root respiration to daytime CO<subscript>2</subscript> emission is 21% along transects in mature tree stands. At locations 0.5m from trees this is up to 80% of the total emissions, but it is negligible at locations more than 1.3m away. This means that CO<subscript>2</subscript> emission measurements well away from trees are free of any root respiration contribution and thus represent only peat oxidation emission. We find daytime mean annual CO<subscript>2</subscript> emission from peat oxidation alone of 94 t ha<superscript>-1</superscript> yr<superscript>-1</superscript> at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha<superscript>-1</superscript> yr<superscript>-1</superscript> after correction for the effect of diurnal temperature fluctuations, which resulted in a 14.5% reduction of the daytime emission. There is a positive correlation between mean longterm water table depths and peat oxidation CO<subscript>2</subscript> emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO<subscript>2</subscript> emissions. The increase in the temperature of the surface peat due to plantation development may explain over 50% of peat oxidation emissions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 18106277
- Volume :
- 8
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Biogeosciences Discussions
- Publication Type :
- Academic Journal
- Accession number :
- 67401612
- Full Text :
- https://doi.org/10.5194/bgd-8-8269-2011