TY - JOUR
T1 - Effect of interannual precipitation variability on dryland productivity
T2 - A global synthesis
AU - Gherardi, Laureano A.
AU - Sala, Osvaldo
N1 - Funding Information:
We acknowledge the work of all researchers that collected, corrected, and made available these data through the years. We thank L.G. Reichmann, L. Yahdjian, E. Jobbágy, Owen P.B.R. McKenna, and A.G. Gil for earlier discussion of ideas and input. We appreciate the contribution of Dan Childers, Nancy Grimm, Sharon Hall, and Jingle Wu. This research was supported by Arizona State University, Global Drylands Center, and NSF grants: DEB 1754106, DEB 1456597, DEB 1235828, and DEB 1354732.
Publisher Copyright:
© 2018 John Wiley & Sons Ltd
PY - 2019/1
Y1 - 2019/1
N2 - Climate-change assessments project increasing precipitation variability through increased frequency of extreme events. However, the effects of interannual precipitation variance per se on ecosystem functioning have been largely understudied. Here, we report on the effects of interannual precipitation variability on the primary production of global drylands, which include deserts, steppes, shrublands, grasslands, and prairies and cover about 40% of the terrestrial earth surface. We used a global database that has 43 datasets, which are uniformly distributed in parameter space and each has at least 10 years of data. We found (a) that at the global scale, precipitation variability has a negative effect on aboveground net primary production. (b) Expected increases in interannual precipitation variability for the year 2,100 may result in a decrease of up to 12% of the global terrestrial carbon sink. (c) The effect of precipitation interannual variability on dryland productivity changes from positive to negative along a precipitation gradient. Arid sites with mean precipitation under 300 mm/year responded positively to increases in precipitation variability, whereas sites with mean precipitation over 300 mm/year responded negatively. We propose three complementary mechanisms to explain this result: (a) concave-up and concave-down precipitation–production relationships in arid vs. humid systems, (b) shift in the distribution of water in the soil profile, and (c) altered frequency of positive and negative legacies. Our results demonstrated that enhanced precipitation variability will have direct impacts on global drylands that can potentially affect the future terrestrial carbon sink.
AB - Climate-change assessments project increasing precipitation variability through increased frequency of extreme events. However, the effects of interannual precipitation variance per se on ecosystem functioning have been largely understudied. Here, we report on the effects of interannual precipitation variability on the primary production of global drylands, which include deserts, steppes, shrublands, grasslands, and prairies and cover about 40% of the terrestrial earth surface. We used a global database that has 43 datasets, which are uniformly distributed in parameter space and each has at least 10 years of data. We found (a) that at the global scale, precipitation variability has a negative effect on aboveground net primary production. (b) Expected increases in interannual precipitation variability for the year 2,100 may result in a decrease of up to 12% of the global terrestrial carbon sink. (c) The effect of precipitation interannual variability on dryland productivity changes from positive to negative along a precipitation gradient. Arid sites with mean precipitation under 300 mm/year responded positively to increases in precipitation variability, whereas sites with mean precipitation over 300 mm/year responded negatively. We propose three complementary mechanisms to explain this result: (a) concave-up and concave-down precipitation–production relationships in arid vs. humid systems, (b) shift in the distribution of water in the soil profile, and (c) altered frequency of positive and negative legacies. Our results demonstrated that enhanced precipitation variability will have direct impacts on global drylands that can potentially affect the future terrestrial carbon sink.
KW - aboveground net primary production
KW - climate change
KW - interannual variability
KW - legacy effect
KW - nonlinear response
KW - precipitation
KW - soil water
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U2 - 10.1111/gcb.14480
DO - 10.1111/gcb.14480
M3 - Article
C2 - 30338886
AN - SCOPUS:85056902567
SN - 1354-1013
VL - 25
SP - 269
EP - 276
JO - Global change biology
JF - Global change biology
IS - 1
ER -