Soil nitrous oxide emissions increase temporarily, whilst soil methane fluxes change little, after clearing savanna woodland for agriculture in tropical northern Australia
Abstract
Northern Australia may experience future land-use change from savanna to agriculture to provide food security in response to climate change and export opportunities. Clearing tropical savanna leads to large vegetation carbon losses, from fire and decomposition, but may also lead to net methane (CH4) and nitrous oxide (N2O) emissions during and after the clearing event. There is great uncertainty as to the impact of vegetation clearing upon CH4 and N2O soil exchange processes in tropical savannas. We measured soil CH4 and N2O flux periodically over 18 months using static manual chambers near Katherine, Northern Australia. A 295 ha area of savanna woodland was cleared after 6 months. Savanna soil ranged from being a mean CH4 sink of -2 to -12 μg C m-2 h-1 in the dry season, to being a mean CH4 source of 5 to 10 μg C m-2 h-1 in the wet season. Of the 72 manual chambers in the adjacent savanna woodland (n=36) and cleared savanna area (n=36), some were always a net CH4 source, and emissions were greater close to trees (
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2013
- Bibcode:
- 2013EGUGA..15.6757L