Similar response of labile and resistant soil organic matter pools to changes in temperature.
Our understanding of the relationship between the decomposition of soil organic matter (SOM) and soil temperature affects our predictions of the impact of climate change on soil-stored carbon. One current opinion is that the decomposition of soil labile carbon is sensitive to temperature variation whereas resistant components are insensitive. The resistant carbon or organic matter in mineral soil is then assumed to be unresponsive to global warming. But the global pattern and magnitude of the predicted future soil carbon stock will mainly rely on the temperature sensitivity of these resistant carbon pools. To investigate this sensitivity, we have incubated soils under changing temperature. Here we report that SOM decomposition or soil basal respiration rate was significantly affected by changes in SOM components associated with soil depth, sampling method and incubation time. We find, however, that the temperature sensitivity for SOM decomposition was not affected, suggesting that the temperature sensitivity for resistant organic matter pools does not differ significantly from that of labile pools, and that both types of SOM will therefore respond similarly to global warming.
Fang
Changming
C
School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK. c.fang@abdn.ac.uk
Smith
Pete
P
Moncrieff
John B
JB
Smith
Jo U
JU
D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism; D019069:Cell Respiration; D002980:Climate; D017752:Greenhouse Effect; D009930:Organic Chemicals / Q000378:metabolism*; D028222:Picea / Q000502:physiology; D006109:Poaceae / Q000502:physiology; D012606:Scotland; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D013696:Temperature; D013997:Time Factors; D014197:Trees / Q000502:physiology
D009930:Organic Chemicals; D012987:Soil; D002244:Carbon