HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (26) Citing Articles via Google Scholar Google Scholar Articles by Conant, R. T. Articles by Klopatek, C. C. Search for Related Content PubMed Articles by Conant, R. T. Articles by Klopatek, C. C. GeoRef GeoRef Citation Agricola Articles by Conant, R. T. Articles by Klopatek, C. C.

DIVISION S-7-FOREST & RANGE SOILS

Environmental Factors Controlling Soil Respiration in Three Semiarid Ecosystems

^a Natural Resource Ecology Lab., Colorado State Univ., Fort Collins, CO 80523-1499 USA
^b Dep. of Botany, Arizona State Univ., Tempe, AZ 85287-1601 USA
^c USDA Forest Service, c/o Dep. of Microbiology, Arizona State Univ., Tempe, AZ 85287-2701 USA

conant{at}nrel.colostate.edu

Previous research suggests that soil organic C pools may be a feature of semiarid regions that are particularly sensitive to climatic changes. We instituted an 18-mo experiment along an elevation gradient in northern Arizona to evaluate the influence of temperature, moisture, and soil C pool size on soil respiration. Soils, from underneath different tree canopy types and interspaces of three semiarid ecosystems, were moved upslope and/or downslope to modify soil climate. Soils moved downslope experienced increased temperature and decreased precipitation, resulting in decreased soil moisture and soil respiration (as much as 23 and 20%, respectively). Soils moved upslope to more mesic, cooler sites had greater soil water content and increased rates of soil respiration (as much as 40%), despite decreased temperature. Soil respiration rates normalized for total C were not significantly different within any of the three incubation sites, indicating that under identical climatic conditions, soil respiration is directly related to soil C pool size for the incubated soils. Normalized soil respiration rates between sites differed significantly for all soil types and were always greater for soils incubated under more mesic, but cooler, conditions. Total soil C did not change significantly during the experiment, but estimates suggest that significant portions of the rapidly cycling C pool were lost. While long-term decreases in aboveground and belowground detrital inputs may ultimately be greater than decreased soil respiration, the initial response to increased temperature and decreased precipitation in these systems is a decrease in annual soil C efflux.

Abbreviations: DS, Desert Scrub Site • PJ, Pinyon–Juniper Site • PP, Ponderosa Pine Site • i, interspace cover type • j, juniper cover type • p, pinyon cover type • pp, ponderosa pine cover type

This article has been cited by other articles:

				G. Wieser, A. Gruber, M. Bahn, E. Catala, E. Carrillo, M. S. Jimenez, and D. Morales Respiratory fluxes in a Canary Islands pine forest Tree Physiol, March 1, 2009; 29(3): 457 - 466. [Abstract] [Full Text] [PDF]

				J. E.T. McLain and D. A. Martens Moisture Controls on Trace Gas Fluxes in Semiarid Riparian Soils Soil Sci. Soc. Am. J., February 2, 2006; 70(2): 367 - 377. [Abstract] [Full Text] [PDF]

				R. Stottlemyer Biogeochemistry of a Treeline Watershed, Northwestern Alaska J. Environ. Qual., November 1, 2001; 30(6): 1990 - 1998. [Abstract] [Full Text] [PDF]