Investigations into the effects of anthropogenic disturbance on greenhouse gas emissions from tropical peatlands are relatively well documented. However, the effects of such disturbance on fluvial carbon (C) losses has, thus far, been overlooked and remains unaccounted for in these ecosystem C budgets. Here, three land-cover classes in Central Kalimantan, Indonesia, were investigated in order to determine the effect of tropical peatland disturbance on fluvial organic C budgets. Intact peat swamp forest (IPSF), moderately disturbed and severely disturbed peat swamp forest (DPSF1 and 2) catchments were monitored for one year. Results demonstrate a trend of increasing annual total organic carbon (TOC) yields with increasing drainage severity, from 63 in IPSF to 105 and 131 g C m-2 y(1 in DPSF1 and 2, respectively. Including this routinely-ignored fluvial C loss component in the disturbed peatland ecosystem C budget increases the estimated total C loss by 30%. Radiocarbon analysis of dissolved organiC carbon (DOC) reveals that whilst DOC leaching from IPSF was derived from recent primary production, DOC leaching from the two disturbed sites was comprised of much older C, originating from deep within the peat column. The TOC flux from the Sebangau River basin was estimated to be 0.46 teragrams y(1, which upon regional extrapolation indicates that Indonesian rivers account for 10% of the global annual riverine DOC export to the ocean. There were no significant differences between sites in the quality of the organic C lost, but DOC lost from disturbed sites was generally less aromatic than from the intact site. It is recognized that a large portion of this labile C will be emitted to the atmosphere via biotic decomposition. Since 1990, peatland disturbance has resulted in a 53% increase in fluvial organic C export from Southeast Asia, an increase that alone approximates the entire annual fluvial organic C flux from European peatlands.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:542448 |
| Date | January 2011 |
| Creators | Moore, Sam |
| Publisher | Open University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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