Taking the pulse of the skin of the earth: quantifying the spatial and temporal variability in soil biogeochemical cycling and stream aqueous losses
Abstract
Land-water linkages between the spatial and temporal variability in soil carbon cycling and stream export remains poorly characterized. These gaps are particularly large in dryland regions that are defined by the scarcity of water and thought to be highly responsive to environmental stressors such as climate and fire. Here we show advances in characterizing the spatial and temporal variation in carbon dioxide effluxes along an elevation gradient in the Reynolds Creek Critical Zone Observatory in SW Idaho using a combination of automated chamber techniques, eddy covariance, and manual measurements. We compare these losses to spatial and temporal patterning of dissolved organic carbon and inorganic carbon concentrations and export using a combination of spatial sampling, grab, autosampler, and automated sensors. Automated force diffusion chambers detected large differences in carbon dioxide pulse dynamics along the elevation gradient. Growing season carbon dioxide fluxes were 3 times higher at the 435 mm mean annual precipitation (MAP) site compared than the lowest elevation sites at 298 and 345 MAP sites and >1.5 higher than the 994 mm mean annual precipitation (MAP) site over the same period. Dissolved organic and inorganic carbon concentrations averaged 12.7 and 14.4 mg C/L across the streams, increased in concentration as the streams dried. Growing season carbon dioxide fluxes were 8-15 times larger than first order annual estimates of annual C export from the watershed. Combined, advances in characterizing the pulse of the skin of the earth are helping to improve carbon budgets and understand the timing and relative partitioning of fluxes of carbon at the plot to watershed scale.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMEP42B..01L
- Keywords:
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- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCESDE: 1039 Alteration and weathering processes;
- GEOCHEMISTRYDE: 1813 Eco-hydrology;
- HYDROLOGYDE: 1824 Geomorphology: general;
- HYDROLOGY