Change in dominance determines herbivore effects on plant biodiversity

Koerner, Sally E and Smith, Melinda D and Burkepile, Deron E and Hanan, Niall P and Avolio, Meghan L and Collins, Scott L and Knapp, Alan K and Lemoine, Nathan P and Forrestel, Elisabeth J and Eby, Stephanie and Thompson, Dave and Aguado-Santacruz, Gerardo A and Anderson, John P and Anderson, Michael T and Angassa, Ayana and Bagchi, Sumanta and Bakker, Elisabeth S and Bastin, Gary and Baur, Lauren E and Beard, Karen H and Beever, Erik A and Bohlen, Patrick J and Boughton, Elizabeth H and Canestro, Don and Cesa, Ariela and Chaneton, Enrique and Cheng, Jimin and D'Antonio, Carla M and Deleglise, Claire and Dembele, Fadiala and Dorrough, Josh and Eldridge, David J and Fernandez-Going, Barbara and Fernandez-Lugo, Silvia and Fraser, Lauchlan H and Freedman, Bill and Garcia-Salgado, Gonzalo and Goheen, Jacob R and Guo, Liang and Husheer, Sean and Karembe, Moussa and Knops, Johannes MH and Kraaij, Tineke and Kulmatiski, Andrew and Kytoviita, Minna-Maarit and Lezama, Felipe and Loucougaray, Gregory and Loydi, Alejandro and Milchunas, Dan G and Milton, Suzanne J and Morgan, John W and Moxham, Claire and Nehring, Kyle C and Olff, Han and Palmer, Todd M and Rebollo, Salvador and Riginos, Corinna and Risch, Anita C and Rueda, Marta and Sankaran, Mahesh and Sasaki, Takehiro and Schoenecker, Kathryn A and Schultz, Nick L and Schutz, Martin and Schwabe, Angelika and Siebert, Frances and Smit, Christian and Stahlheber, Karen A and Storm, Christian and Strong, Dustin J and Su, Jishuai and Tiruvaimozhi, Yadugiri and Tyler, Claudia and Val, James and Vandegehuchte, Martijn L and Veblen, Kari E and Vermeire, Lance T and Ward, David and Wu, Jianshuang and Young, Truman P and Yu, Qiang and Zelikova, Tamara Jane (2018) Change in dominance determines herbivore effects on plant biodiversity. In: NATURE ECOLOGY & EVOLUTION, 2 (12). pp. 1925-1932.

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Abstract

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.

Item Type:	Journal Article
Publication:	NATURE ECOLOGY & EVOLUTION
Publisher:	NATURE PUBLISHING GROUP
Additional Information:	Copyright of this article belongs to NATURE PUBLISHING GROUP
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	08 Feb 2019 08:54
Last Modified:	08 Feb 2019 12:05
URI:	http://eprints.iisc.ac.in/id/eprint/61378

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