Between micro and global scales- Environmental gradients in ecosystem studies (Invited)
Abstract
Changes in climate and global temperature are upon us and it is imperative that studies investigating microbial and biogeochemical processes and responses to such changes are representative of ecosystem-scale feedback to warming. Predictive understanding of the potential climate feedback of terrestrial carbon (C) is hindered by lack of information concerning responses of soil C to warming. Current theories and models used to describe soil organic C (SOC) temperature responses are largely based on surface soil C extrapolated from short-term laboratory incubations and from chemical thermodynamics of individual SOC fractions. Such approaches have proven inadequate to draw generalizations of soil C responses to warming at the ecosystem scale. Mean annual temperature gradients represent a space for time substitution useful to investigate medium to long-term (decades to centuries) effects of warming on SOC quality and stabilization in situ, with the possibility to extrapolate at the ecosystem scale. Gradients in mean annual temperature are also representative of long-term (i.e., centuries) responses of the microbial community to temperature and soil environmental characteristics. Our work along a 22 degrees Celsius continental mean annual temperature gradient in forest ecosystems provides information on the effect of mean annual temperature on SOC decomposition and stabilization and on microbial community and function. Results predict that, in upland forests, responsiveness of most SOC decomposition to warming will be less than currently modeled, with large temperature effect being limited to the most labile fractions of C.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.B22D..03F
- Keywords:
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- 0428 BIOGEOSCIENCES Carbon cycling;
- 1630 GLOBAL CHANGE Impacts of global change