Title: Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

Abstract

Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitation changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. Here, we used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturatingmore » in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. Finally, this highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change experiments. Additionally, policy and land management decisions related to global change scenarios should consider how ANPP and BNPP responses may differ, and that ecosystem responses to extreme events might not be predicted from relationships found under moderate environmental changes.« less

Authors:

Wilcox, Kevin R.  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-6829-1148"

Shi, Zheng ^[1]; Gherardi, Laureano A. ^[2]; Lemoine, Nathan P. ^[3]; Koerner, Sally E. ^[4]; Hoover, David L. ^[5]; Bork, Edward ^[6]; Byrne, Kerry M. ^[7]; Cahill, James ^[8]; Collins, Scott L. ^[9]; Evans, Sarah ^[10]; Gilgen, Anna K. ^[11]; Holub, Petr ^[12]; Jiang, Lifen  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-1546-8189"

Knapp, Alan K. ^[3]; LeCain, Daniel ^[5]; Liang, Junyi ^[1]; Garcia-Palacios, Pablo ^[13]; Peñuelas, Josep ^[14]; Pockman, William T. ^[9] more »; Smith, Melinda D. ^[3]; Sun, Shanghua ^[15]; White, Shannon R. ^[16]; Yahdjian, Laura ^[17]; Zhu, Kai  ^[18];

• Search DOE PAGES for author "Zhu, Kai"
• Search DOE PAGES for ORCID "0000-0003-1587-3317"

Luo, Yiqi ^[1] « less

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+ Show Author Affiliations

1. Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology
2. Arizona State Univ., Tempe, AZ (United States). School of Life Sciences
3. Colorado State Univ., Fort Collins, CO (United States). Dept. of Biology & Graduate Degree Program in Ecology
4. Univ. of South Florida, Tampa, FL (United States). Dept. of Integrative Biology
5. US Dept. of Agriculture (USDA)., Fort Collins, CO (United States). Agriculture Research Service (ARS)
6. Univ. of Alberta, Edmonton, AB (Canada). Agricultural, Food & Nutritional Science
7. Humboldt State Univ., Arcata, CA (United States). Dept. of Environmental Science and Management
8. Univ. of Alberta, Edmonton, AB (Canada). Dept. of Biological Sciences
9. Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Biology
10. Michigan State Univ., Hickory Corners, MI (United States). Dept. of Integrative Biology, Dept. of Microbiology and Molecular Genetics and Kellogg Biological Station
11. Federal Inst. of Technology, Zurich (Switzerland). Dept. of Environmental Systems Science
12. Czech Academy of Sciences, Brno (Czech Republic). Global Change Research Inst.
13. Univ. Rey Juan Carlos, Mostoles (Spain). Area of Biodiversity and Conservation, Dept. of Biology, Geology, Physics and Inorganic Chemistry, Higher School of Experimental Sciences and Technology
14. Consejo Superior de Investigaciones Cientificas (CSIC), Catalonia (Spain). Global Ecology Unit; Centre for Research on Ecology and Forestry Applications (CREAF), Catalonia (Spain)
15. Northwest A&F Univ., Yangling (China). College of Forestry
16. Government of Alberta, Edmonton, AB (Canada). Environment and Parks
17. Univ. de Buenos Aires, Buenos Aires (Argentina). Faculty of Agronomy, Inst. for Physiological and Ecological Research Associated with Agriculture (IFEVA), National Research Council Scientific and Technical
18. Rice Univ., Houston, TX (United States). Dept. of BioSciences; Univ. of Texas, Arlington, TX (United States). Dept. of Biology

Publication Date:

Sun Apr 02 00:00:00 EDT 2017

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1394445

Grant/Contract Number:  

AC05-00OR22725; 1137293; 1027319; 1456597; AFRI 2016-67012-25169; SyG-2013-610028 IMBALANCE-P

Resource Type:

Accepted Manuscript

Journal Name:

Global Change Biology

Additional Journal Information:

Journal Volume: 23; Journal Issue: 10; Journal ID: ISSN 1354-1013

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; aboveground net primary productivity; belowground net primary productivity; biomass allocation; climate change; grasslands; meta-analysis; root biomass