PLANT AND MICROBE CONTRIBUTION TO COMMUNITY RESILIENCE IN A DIRECTIONALLY CHANGING ENVIRONMENT
2008; Wiley; Volume: 78; Issue: 3 Linguagem: Inglês
10.1890/07-1092.1
ISSN1557-7015
AutoresKatharine N. Suding, Isabel W. Ashton, Heather A. Bechtold, William D. Bowman, Megan L. Mobley, Ryan Winkleman,
Tópico(s)Ecology and Vegetation Dynamics Studies
ResumoEcological MonographsVolume 78, Issue 3 p. 313-329 Article PLANT AND MICROBE CONTRIBUTION TO COMMUNITY RESILIENCE IN A DIRECTIONALLY CHANGING ENVIRONMENT Katharine N. Suding, Corresponding Author Katharine N. Suding [email protected] Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USA E-mail: [email protected]Search for more papers by this authorIsabel W. Ashton, Isabel W. Ashton Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USASearch for more papers by this authorHeather Bechtold, Heather Bechtold Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USA Present address: Department of Biology, Idaho State University, Pocatello, Idaho 83209 USA.Search for more papers by this authorWilliam D. Bowman, William D. Bowman Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USASearch for more papers by this authorMegan L. Mobley, Megan L. Mobley Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USA Present address: Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina 27708 USA.Search for more papers by this authorRyan Winkleman, Ryan Winkleman Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USASearch for more papers by this author Katharine N. Suding, Corresponding Author Katharine N. Suding [email protected] Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USA E-mail: [email protected]Search for more papers by this authorIsabel W. Ashton, Isabel W. Ashton Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USASearch for more papers by this authorHeather Bechtold, Heather Bechtold Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USA Present address: Department of Biology, Idaho State University, Pocatello, Idaho 83209 USA.Search for more papers by this authorWilliam D. Bowman, William D. Bowman Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USASearch for more papers by this authorMegan L. Mobley, Megan L. Mobley Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309 USA Present address: Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina 27708 USA.Search for more papers by this authorRyan Winkleman, Ryan Winkleman Department of Ecology and Evolutionary Biology, University of California at Irvine, Irvine, California 92697-2525 USASearch for more papers by this author First published: 01 August 2008 https://doi.org/10.1890/07-1092.1Citations: 55 Corresponding Editor: B. J. M. Bohannon. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract To understand the role biota play in resilience or vulnerability to environmental change, we investigated soil, plant, and microbial responses to a widespread environmental change, increased nitrogen (N). Our aim was to test the plant–soil threshold hypothesis: that changed biotic structure influences resilience to accumulated changes in N. For six years, we removed one of two codominant species, Geum rossii and Deschampsia caespitosa, in moist-meadow alpine tundra in Colorado, USA. We also manipulated nutrient availability by adding carbon (C) or N, separately and in combination with the species removals. Consistent with our hypothesis, Geum was associated with soil feedbacks that slowed rates of N cycling and Deschampsia with feedbacks that increased rates of N cycling. After a four-year initial resilience period, Geum dramatically declined (by almost 70%) due to increasing N availability. In contrast, Deschampsia abundance did not respond to changes in N supply; it only responded to the removal of Geum. Forbs and graminoids responded more positively to Deschampsia removal than to Geum removal, indicating stronger competitive effects by Deschampsia. The changed biotic interactions appear to have community-level consequences: after six years of Geum (but not Deschampsia) removal, evenness of the community declined by over 35%. Increased N affected the soil–microbial feedbacks, particularly in association with Geum. Microbial biomass N declined at higher N, as did the activities of two C-acquiring and one N-acquiring extracellular microbial enzymes. In the presence of Geum, N fertilization slowed the activity of phenol oxidase, a tannin-degrading enzyme, suggesting that microbes shift from degrading Geum-derived compounds. In the absence of Geum, acid phosphatase activity increased, suggesting increased phosphorus limitation in association with Deschampsia. With continued N deposition forecast for this system, these results suggest that initial resilience of Geum to increased N will be overwhelmed through elimination of microbial feedbacks. Once Geum declines, the loss will indirectly facilitate Deschampsia via competitive release. Because Deschampsia exerts strong competitive effects on subordinate species, increased Deschampsia abundance may be accompanied by a community-wide drop in diversity. We conclude that plant–soil feedbacks through the microbial community can influence vulnerability to exogenous changes in N and contribute to threshold dynamics. Citing Literature Supporting Information Filename Description https://dx.doi.org/10.6084/m9.figshare.c.3309366 Research data pertaining to this article is located at figshare.com: Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume78, Issue3August 2008Pages 313-329 RelatedInformation
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