HR: 0800h
AN: B41C-0638 [Abstracts]
TI: A novel approach to inferring real temperature sensitivity and soil carbon dynamics from soil respiration measurements
AU: * Gu, L
EM: lianhong-gu@ornl.gov
AF: Oak Ridge National Laboratory, Environmental Sciences Division
Building 1509, MS-6335, Oak Ridge, TN 37831, United States
AU: Hanson, P
EM: hansonpj@ornl.gov
AF: Oak Ridge National Laboratory, Environmental Sciences Division
Building 1509, MS-6335, Oak Ridge, TN 37831, United States
AU: Post, M
EM: postwmiii@ornl.gov
AF: Oak Ridge National Laboratory, Environmental Sciences Division
Building 1509, MS-6335, Oak Ridge, TN 37831, United States
AB:
Our previous study established that it is not reliable to estimate the temperature sensitivity of soil organic matter
decomposition directly from soil respiration measurements. Arbitrary values of temperature sensitivity can be
obtained because of the convolution between the dynamics of fast turnover carbon pools and the temporal
progression in environmental factors. This problem is behind many controversies concerning roles of soil carbon
in climate change. Here we introduce a novel approach to analyzing soil respiration measurements that
overcomes this problem. The new approach is called 'Localized Ratio Fitting' (LRF). LRF takes advantage of
different time scales involved in soil carbon pool dynamics and variations in environmental factors. Through
model simulation, we show that LRF can accurately retrieve the real temperature sensitivity of soil organic matter
decomposition. Furthermore, we demonstrate that once the temperature sensitivity is properly accounted for, soil
respiration measurements can be used to infer the dynamics of litter inputs to soil carbon pools. Therefore, LRF
will not only improve the reliability in the interpretation of soil respiration measurements but also expand the
application of these measurements.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0429 Climate dynamics (1620)
DE: 0430 Computational methods and data processing
DE: 0438 Diel, seasonal, and annual cycles (4227)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting