title: Macroecological and macroevolutionary patterns of leaf herbivory across vascular plants.
abstract: The consumption of plants by animals underlies important evolutionary and ecological processes in nature. Arthropod herbivory evolved approximately 415 Ma and the ensuing coevolution between plants and herbivores is credited with generating much of the macroscopic diversity on the Earth. In contemporary ecosystems, herbivory provides the major conduit of energy from primary producers to consumers. Here, we show that when averaged across all major lineages of vascular plants, herbivores consume 5.3% of the leaf tissue produced annually by plants, whereas previous estimates are up to 3.8× higher. This result suggests that for many plant species, leaf herbivory may play a smaller role in energy and nutrient flow than currently thought. Comparative analyses of a diverse global sample of 1058 species across 2085 populations reveal that models of stabilizing selection best describe rates of leaf consumption, and that rates vary substantially within and among major plant lineages. A key determinant of this variation is plant growth form, where woody plant species experience 64% higher leaf herbivory than non-woody plants. Higher leaf herbivory in woody species supports a key prediction of the plant apparency theory. Our study provides insight into how a long history of coevolution has shaped the ecological and evolutionary relationships between plants and herbivores.
authors.affiliation: Department of Biology, University of Toronto-Mississauga, Mississauga, Ontario, Canada L5L 1C6 mart.turcotte@gmail.com.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Turcotte
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1.
authors.forename: T Jonathan
authors.initials: TJ
authors.lastname: Davies
authors.affiliation: Department of Biology, University of Toronto-Mississauga, Mississauga, Ontario, Canada L5L 1C6 Department of Biology, University of Ottawa, Ontario, Canada K1N 6N5.
authors.forename: Christina J M
authors.initials: CJ
authors.lastname: Thomsen
authors.affiliation: Department of Biology, University of Toronto-Mississauga, Mississauga, Ontario, Canada L5L 1C6.
authors.forename: Marc T J
authors.initials: MT
authors.lastname: Johnson
mesh_terms: D000818:Animals; D001181:Arthropods / Q000502:physiology*; D005075:Biological Evolution; D019669:Embryophyta / Q000235:genetics / Q000502:physiology*; D020387:Food Chain; D060434:Herbivory; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000502:physiology; D017422:Sequence Analysis, DNA
keywords: Ornstein–Uhlenbeck; grazing; plant defence evolution; plant–herbivore interactions; primary consumption; trophic interactions