caa a22 4500 605517053 CHVBK 20210128100717.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s10533-015-0078-3 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0078-3 Climatic and landscape influences on soil moisture are primary determinants of soil carbon fluxes in seasonally snow-covered forest ecosystems [Elektronische Daten] [Clare Stielstra, Kathleen Lohse, Jon Chorover, Jennifer McIntosh, Greg Barron-Gafford, Julia Perdrial, Marcy Litvak, Holly Barnard, Paul Brooks] A changing climate has the potential to mobilize soil carbon, shifting seasonally snow-covered, forested ecosystems from carbon sinks to sources. To determine the sensitivity of soil carbon fluxes to changes in temperature and moisture, we quantified seasonal and spatial variability of soil carbon dioxide (CO2) fluxes (N=746) and dissolved organic carbon (DOC) in leachate (N=260) in high-elevation, mixed conifer forests in Arizona and New Mexico. All sites have cold winters, warm summers, and bimodal soil moisture patterns associated with snowmelt and summer monsoon rainfall. We employed a state factor approach, quantifying how distal controls (parent material, regional climate, topography) interacted with proximal variability in soil temperature (−3 to 26°C) and moisture (2-76%) to influence carbon effluxes. Carbon loss was dominated by CO2 flux (250-1220g Cm−2year−1) rather than leached DOC (7.0-9.4g C m−2year−1). Significant differences in mean growing season CO2 flux were associated with parent material and aspect; differences appear to be mediated by how these distal controls influence primarily moisture and secondarily temperature. Across all sites, a multiple linear regression model (MLR) relying on moisture and temperature best described growing season CO2 fluxes (r2=0.63, p<0.001). During winter, the MLR describing soil CO2 flux (r2=0.98, p<0.001) relied on distal factors including snow cover, clay content, and bulk carbon, all factors that influence liquid water content. Our findings highlight the importance of state factors in controlling soil respiration primarily through influencing spatial and temporal heterogeneity in soil moisture. Springer International Publishing Switzerland, 2015 Carbon cycle nationallicence Climate nationallicence Forests nationallicence Soil moisture nationallicence Soil respiration nationallicence Stielstra Clare Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ, USA aut Lohse Kathleen Department of Biological Sciences, Idaho State University, Pocatello, ID, USA aut Chorover Jon Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ, USA aut McIntosh Jennifer Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ, USA aut Barron-Gafford Greg School of Geography & Development, University of Arizona, Tucson, AZ, USA aut Perdrial Julia Department of Geology, University of Vermont, Burlington, VT, USA aut Litvak Marcy Department of Biological Science, University of New Mexico, Albuquerque, NM, USA aut Barnard Holly Department of Geography and INSTAAR, University of Colorado, Boulder, CO, USA aut Brooks Paul Department of Geology/Geophysics, University of Utah, 115 So. 1460 East, 84112-0102, Salt Lake City, UT, USA aut Biogeochemistry Springer International Publishing 123/3(2015-04-01), 447-465 0168-2563 123:3<447 2015 123 10533 https://doi.org/10.1007/s10533-015-0078-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0078-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stielstra Clare Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ, USA aut NATIONALLICENCE 700 1- Lohse Kathleen Department of Biological Sciences, Idaho State University, Pocatello, ID, USA aut NATIONALLICENCE 700 1- Chorover Jon Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ, USA aut NATIONALLICENCE 700 1- McIntosh Jennifer Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ, USA aut NATIONALLICENCE 700 1- Barron-Gafford Greg School of Geography & Development, University of Arizona, Tucson, AZ, USA aut NATIONALLICENCE 700 1- Perdrial Julia Department of Geology, University of Vermont, Burlington, VT, USA aut NATIONALLICENCE 700 1- Litvak Marcy Department of Biological Science, University of New Mexico, Albuquerque, NM, USA aut NATIONALLICENCE 700 1- Barnard Holly Department of Geography and INSTAAR, University of Colorado, Boulder, CO, USA aut NATIONALLICENCE 700 1- Brooks Paul Department of Geology/Geophysics, University of Utah, 115 So. 1460 East, 84112-0102, Salt Lake City, UT, USA aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 123/3(2015-04-01), 447-465 0168-2563 123:3<447 2015 123 10533