Contrasting vulnerability of drained tropical and high‐latitude peatlands to fluvial loss of stored carbon

Autor: Vincent Gauci, Timothy G. Jones, Sam Moore, Jakub Hruška, Chris D. Evans, Michael F. Billett, Susan Page, Timothy E H Allott, Chris Freeman, Raija Laiho, Mark H. Garnett, Edward Tipping
Rok vydání: 2014
Předmět:
Zdroj: Global Biogeochemical Cycles. 28:1215-1234
ISSN: 1944-9224
0886-6236
Popis: Carbon sequestration and storage in peatlands rely on consistently high water tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2sinks to large CO2sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but with marked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage;14C measurements from UK blanket bogs suggest that exported DOC remains young (500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age.
Databáze: OpenAIRE
Externí odkaz: