Soil Respiration in the Cold Desert Environment of the Colorado Plateau (USA): Abiotic Regulators and Thresholds
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Decomposition is central to understanding ecosystem carbon exchange and nutrient-release processes. Unlike mesic ecosystems, which have been extensively studied, xeric landscapes have received little attention; as a result, abiotic soil-respiration regulatory processes are poorly understood in xeric environments. To provide a more complete and quantitative understanding about how abiotic factors influence soil respiration in xeric ecosystems, we conducted soil- respiration and decomposition-cloth measurements in the cold desert of southeast Utah. Our study evaluated when and to what extent soil texture, moisture, temperature, organic carbon, and nitrogen influence soil respiration and examined whether the inverse-texture hypothesis applies to decomposition. Within our study site, the effect of texture on moisture, as described by the inverse texture hypothesis, was evident, but its effect on decomposition was not. Our results show temperature and moisture to be the dominant abiotic controls of soil respiration. Specifically, temporal offsets in temperature and moisture conditions appear to have a strong control on soil respiration, with the highest fluxes occurring in spring when temperature and moisture were favorable. These temporal offsets resulted in decomposition rates that were controlled by soil moisture and temperature thresholds. The highest fluxes of CO2 occurred when soil temperature was between 10 and 16 °C and volumetric soil moisture was greater than 10%. Decomposition-cloth results, which integrate decomposition processes across several months, support the soil-respiration results and further illustrate the seasonal patterns of high respiration rates during spring and low rates during summer and fall. Results from this study suggest that the parameters used to predict soil respiration in mesic ecosystems likely do not apply in cold-desert environments.
KeywordsCold desert Regression tree Soil carbon Soil respiration
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- Breiman, L., Friedman, J.H., Olshen, R.A., Stone, C.G. 1985Classification and Regression TreesWadsworth International GroupBelmont, CA, USAGoogle Scholar
- Carlyle, J.C., Than, U. 1988Abiotic controls of soil respiration beneath an eighteen-year-old Pinus Radiata stand in south-eastern AustraliaJ. Ecol.76654662Google Scholar
- CLIM-MET data obtained from Earth Surface Dynamics ProgramU.S. Geological Survey. http://climchange.cr.usgs.gov/info/sw/clim-met/.
- Jenny, H. 1980The Soil Resource: Origin and BehaviorSpringer-VerlagNew York, NY, USAGoogle Scholar
- Kittel T.G.F., Rosenbloom N.A., Painter T.H., Schimel D.S. and VEMAP participants. 1995. The VEMAP integrated database for modeling United States ecosystem/vegetation sensitivity to climate change. J. Biogeog. 22: 857–862.Google Scholar
- Lloyd, J., Taylor, J.A. 1994On the temperature dependence of soil respirationFunct. Ecol.8315323Google Scholar
- Neff, J.C., Reynolds, R.L., Belnap, J., Lamothe, P. 2005Multi-decadal impacts of grazing on soil physical and biogeochemical properties in southeast UtahEcol. Appl.158795Google Scholar
- Paul, E.A., Clark, F.E. 1989Soil Microbiology and BiochemistryAcademic Press IncSan Diego, CA, USAGoogle Scholar
- Peterjohn, W.T., Melillo, J.M., Steudler, P.A., Newkirk, K.M., Bowles, F.P., Aber, J.D. 1994Response of trace gas fluxes and N availability to experimentally elevated soil temperaturesEcol. Appl.4617625Google Scholar
- Raich, J.W., Schlsinger, W.H. 1992The carbon dioxide flux in soil respiration and its relationship to vegetation and climateTellus44B8199Google Scholar
- Raich, J.W., Rastetter, E.B., Melillo, J.M., Kicklighter, D.W., Steudler, P.A., Peterson, A.L., Grace, B., Moore, ,III, Vörösmarty, C.J. 1991Potential net primary production in South America: application of a global modelEcol. Appl.1399429Google Scholar
- Rastetter, E.B., Ryan, M.G., Shaver, G.R., Melillo, J.M., Nadelhoffer, K.J., Hobbie, J.E., Aber, J.D. 1991A general biogeochemical model describing the responses of C and N cycles in terrestrial ecosystems to changes in CO2climateand N depositionTree Physiol.9101126Google Scholar
- U.S. Department of Agriculture Soil Conservation Service1991Soil survey of Canyonlands Area Utah: Parts of Grand and San Juan CountiesUnited States Department of AgricultureNatural Resource Conservation ServiceSalt Lake City, Utah, USAGoogle Scholar
- Kleve, K., Oechel, W.C., Hom, J.L. 1990Response of black spruce (Picea mariana) ecosystems to soil temperature modification in interior AlsakaCan. J. For. Res.2015301535Google Scholar
- West, N.E., Moore, R.T., Valentine, K.A., Law, L.A., Ogden, P.R., Pinkney, F.C., Tueller, P.T., Robertson, J.H., Beetle, A.A. 1972Galleta: Taxonomy, Ecology, and Management of Hilaria jamesii on Western RangelandsUtah Agricultural Experimental Station, Utah State UniversityLogan, UtahGoogle Scholar
- West, N.E. 1981Nutrient cycling in desert environmentsGoodall, D.W.Perry, R.A. eds. Xeric-land Ecosystems: StructureFunctioning, and ManagementCambridge University PressCambridge, UK301324Google Scholar