title: Invertebrate herbivory increases along an experimental gradient of grassland plant diversity.
abstract: Plant diversity is a key driver of ecosystem functioning best documented for its influence on plant productivity. The strength and direction of plant diversity effects on species interactions across trophic levels are less clear. For example, with respect to the interactions between herbivorous invertebrates and plants, a number of competing hypotheses have been proposed that predict either increasing or decreasing community herbivory with increasing plant species richness. We investigated foliar herbivory rates and consumed leaf biomass along an experimental grassland plant diversity gradient in year eight after establishment. The gradient ranged from one to 60 plant species and manipulated also functional group richness (from one to four functional groups-legumes, grasses, small herbs, and tall herbs) and plant community composition. Measurements in monocultures of each plant species showed that functional groups differed in the quantity and quality of herbivory damage they experienced, with legumes being more damaged than grasses or non-legume herbs. In mixed plant communities, herbivory increased with plant diversity and the presence of two key plant functional groups in mixtures had a positive (legumes) and a negative (grasses) effect on levels of herbivory. Further, plant community biomass had a strong positive impact on consumed leaf biomass, but little effect on herbivory rates. Our results contribute detailed data from a well-established biodiversity experiment to a growing body of evidence suggesting that an increase of herbivory with increasing plant diversity is the rule rather than an exception. Considering documented effects of herbivory on other ecosystem functions and the increase of herbivory with plant diversity, levels of herbivory damage might not only be a result, but also a trigger within the diversity-productivity relationship.
authors.affiliation: Experimental Ecology Group, Department of Biology and Chemistry, University of Osnabrück, Barbarastrasse 13, 49076, Osnabrück, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Loranger
authors.forename: Wolfgang W
authors.initials: WW
authors.lastname: Weisser
authors.forename: Anne
authors.initials: A
authors.lastname: Ebeling
authors.forename: Till
authors.initials: T
authors.lastname: Eggers
authors.forename: Enrica
authors.initials: E
authors.lastname: De Luca
authors.forename: Jessy
authors.initials: J
authors.lastname: Loranger
authors.forename: Christiane
authors.initials: C
authors.lastname: Roscher
authors.forename: Sebastian T
authors.initials: ST
authors.lastname: Meyer
mesh_terms: D000818:Animals; D044822:Biodiversity; D018533:Biomass; D017753:Ecosystem; D007887:Fabaceae; D005858:Germany; D060434:Herbivory; D007448:Invertebrates / Q000502:physiology*; D018515:Plant Leaves; D006109:Poaceae
references.citation: PLoS One. 2010 Aug 06;5(8):e12053
references.pmid: 20700511
references.citation: Ecology. 2009 Dec;90(12):3290-302
references.pmid: 20120799
references.citation: Nature. 2010 Nov 25;468(7323):553-6
references.pmid: 20981010
references.citation: Ecol Lett. 2007 Sep;10(9):835-48
references.pmid: 17663717
references.citation: J Anim Ecol. 2010 May;79(3):709-20
references.pmid: 20202014
references.citation: Ecol Lett. 2009 Oct;12(10):1029-39
references.pmid: 19702636
references.citation: Ecol Lett. 2007 Jun;10(6):522-38
references.pmid: 17498151
references.citation: Am Nat. 2001 Jul;158(1):17-35
references.pmid: 18707312
references.citation: Ecol Lett. 2012 Dec;15(12):1457-64
references.pmid: 23020194
references.citation: Science. 1999 Nov 5;286(5442):1123-7
references.pmid: 10550043
references.citation: Oecologia. 1997 Jul;111(2):233-240
references.pmid: 28307999
references.citation: J Ecol. 2010 Jul;98(4):917-926
references.pmid: 20852667
references.citation: Ecology. 2010 Apr;91(4):1083-91
references.pmid: 20462122
references.citation: Oecologia. 2012 Jun;169(2):453-65
references.pmid: 22120706
references.citation: Oecologia. 2003 Apr;135(2):234-41
references.pmid: 12698345
references.citation: Oecologia. 2006 Nov;150(2):233-46
references.pmid: 16917778
references.citation: Oecologia. 2007 Jun;152(3):435-47
references.pmid: 17356814
references.citation: Oecologia. 2001 Jan;126(2):225-230
references.pmid: 28547621
references.citation: Ecology. 2012 Dec;93(12):2674-82
references.pmid: 23431597
references.citation: Ecology. 2013 Jul;94(7):1499-509
references.pmid: 23951710
references.citation: Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14412-7
references.pmid: 11106378
references.citation: Oecologia. 2008 May;156(2):313-24
references.pmid: 18301924
references.citation: Oecologia. 2006 Mar;147(3):489-500
references.pmid: 16231192
references.citation: J Anim Ecol. 2012 May;81(3):614-27
references.pmid: 22292705
references.citation: Oecologia. 2000 Oct;125(2):271-282
references.pmid: 24595838
references.citation: Am Nat. 1998 Oct;152(4):510-29
references.pmid: 18811361
references.citation: Oecologia. 2002 Jan;130(1):96-104
references.pmid: 28547030