title: Sources of Controversy Surrounding Latitudinal Patterns in Herbivory and Defense.
abstract: Both herbivory and plant defenses against herbivores have been predicted to increase toward tropical regions. Early tests of this latitudinal herbivory-defense hypothesis (LHDH) were supportive, but accumulating evidence has been mixed. We argue that the lack of clarity might be due to heterogeneity in methodology and problems with study design and interpretation. We suggest possible solutions. Latitudinal studies need to carefully consider spatial and phylogenetic scale, to link plant defense measurements to herbivore performance, and to incorporate additional concepts from plant defense theory such as tolerance and induced defense. In addition, we call for consistent measures of herbivory to standardize comparisons across biomes. Improving methodology in future studies of LHDH should resolve much of the current controversy.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada. Electronic address: daniel.anstett@utoronto.ca.
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Anstett
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
authors.forename: Krystal A
authors.initials: KA
authors.lastname: Nunes
authors.affiliation: Department of Plant Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, 612 Wilson Road, East Lansing, MI 48824, USA.
authors.forename: Carina
authors.initials: C
authors.lastname: Baskett
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kotanen
mesh_terms: D060434:Herbivory; D010802:Phylogeny; D010944:Plants
keywords: biogeography; chemical defense; herbivory rates; macroecology; species interactions