TY - JOUR
T1 - Soil texture drives responses of soil respiration to precipitation pulses in the sonoran desert
T2 - Implications for climate change
AU - Cable, Jessica M.
AU - Ogle, Kiona
AU - Williams, David G.
AU - Weltzin, Jake F.
AU - Huxman, Travis E.
N1 - Funding Information:
The authors thank N. English, B. Cable, D. Ignace, D. Potts, A. Eilts, J. Chen, G. Barron-Gafford, and M. Mason for field support. We also acknowledge supports from USDA-CSREES (Grant # 00-35101-9308), SAHRA (Sustainability of Semi-Arid Hydrology and Riparian Areas) under the STC program of NSF, and NSF awards DEB 041-5977, DEB 041-8363, and DEB 041-8134 to T.E.H., J.F.W., and D.G.W. The statistical analysis was partly supported by a DOE NICCR grant (K.O., T.H.).
PY - 2008/9
Y1 - 2008/9
N2 - Climate change predictions for the desert southwestern U.S. are for shifts in precipitation patterns. The impacts of climate change may be significant, because desert soil processes are strongly controlled by precipitation inputs ("pulses") via their effect on soil water availability. This study examined the response of soil respiration-an important biological process that affects soil carbon (C) storage-to variation in pulses representative of climate change scenarios for the Sonoran Desert. Because deserts are mosaics of different plant cover types and soil textures-which create patchiness in soil respiration-we examined how these landscape characteristics interact to affect the response of soil respiration to pulses. Pulses were applied to experimental plots of bare and vegetated soil on contrasting soil textures typical of Sonoran Desert grasslands. The data were analyzed within a Bayesian framework to: (1) determine pulse size and antecedent moisture (soil moisture prior to the pulse) effects on soil respiration, (2) quantify soil texture (coarse vs. fine) and cover type (bare vs. vegetated) effects on the response of soil respiration and its components (plant vs. microbial) to pulses, and (3) explore the relationship between long-term variation in pulse regimes and seasonal soil respiration. Regarding objective (1), larger pulses resulted in higher respiration rates, particularly from vegetated fine-textured soil, and dry antecedent conditions amplified respiration responses to pulses (wet antecedent conditions dampened the pulse response). Regarding (2), autotrophic (plant) activity was a significant source (∼60%) of respiration and was more sensitive to pulses on coarse- versus fine-textured soils. The sensitivity of heterotrophic (microbial) respiration to pulses was highly dependent on antecedent soil water. Regarding (3), seasonal soil respiration was predicted to increase with both growing season precipitation and mean pulse size (but only for pulses between 7 and 25 mm). Thus, the heterogeneity of the desert landscape and the timing or the number of medium-sized pulses is expected to significantly impact desert soil C loss with climate change.
AB - Climate change predictions for the desert southwestern U.S. are for shifts in precipitation patterns. The impacts of climate change may be significant, because desert soil processes are strongly controlled by precipitation inputs ("pulses") via their effect on soil water availability. This study examined the response of soil respiration-an important biological process that affects soil carbon (C) storage-to variation in pulses representative of climate change scenarios for the Sonoran Desert. Because deserts are mosaics of different plant cover types and soil textures-which create patchiness in soil respiration-we examined how these landscape characteristics interact to affect the response of soil respiration to pulses. Pulses were applied to experimental plots of bare and vegetated soil on contrasting soil textures typical of Sonoran Desert grasslands. The data were analyzed within a Bayesian framework to: (1) determine pulse size and antecedent moisture (soil moisture prior to the pulse) effects on soil respiration, (2) quantify soil texture (coarse vs. fine) and cover type (bare vs. vegetated) effects on the response of soil respiration and its components (plant vs. microbial) to pulses, and (3) explore the relationship between long-term variation in pulse regimes and seasonal soil respiration. Regarding objective (1), larger pulses resulted in higher respiration rates, particularly from vegetated fine-textured soil, and dry antecedent conditions amplified respiration responses to pulses (wet antecedent conditions dampened the pulse response). Regarding (2), autotrophic (plant) activity was a significant source (∼60%) of respiration and was more sensitive to pulses on coarse- versus fine-textured soils. The sensitivity of heterotrophic (microbial) respiration to pulses was highly dependent on antecedent soil water. Regarding (3), seasonal soil respiration was predicted to increase with both growing season precipitation and mean pulse size (but only for pulses between 7 and 25 mm). Thus, the heterogeneity of the desert landscape and the timing or the number of medium-sized pulses is expected to significantly impact desert soil C loss with climate change.
KW - Climate change
KW - Eragrostis lehmanniana
KW - Heteropogon contortus
KW - Hierarchical Bayesian
KW - Precipitation change
KW - Soil respiration model
KW - Sonoran Desert
UR - http://www.scopus.com/inward/record.url?scp=52949083560&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=52949083560&partnerID=8YFLogxK
U2 - 10.1007/s10021-008-9172-x
DO - 10.1007/s10021-008-9172-x
M3 - Article
AN - SCOPUS:52949083560
SN - 1432-9840
VL - 11
SP - 961
EP - 979
JO - Ecosystems
JF - Ecosystems
IS - 6
ER -