title: Intraspecific chemical diversity among neighbouring plants correlates positively with plant size and herbivore load but negatively with herbivore damage.
abstract: Intraspecific plant diversity can modify the properties of associated arthropod communities and plant fitness. However, it is not well understood which plant traits determine these ecological effects. We explored the effect of intraspecific chemical diversity among neighbouring plants on the associated invertebrate community and plant traits. In a common garden experiment, intraspecific diversity among neighbouring plants was manipulated using three plant populations of wild cabbage that differ in foliar glucosinolates. Plants were larger, harboured more herbivores, but were less damaged when plant diversity was increased. Glucosinolate concentration differentially correlated with generalist and specialist herbivore abundance. Glucosinolate composition correlated with plant damage, while in polycultures, variation in glucosinolate concentrations among neighbouring plants correlated positively with herbivore diversity and negatively with plant damage levels. The results suggest that intraspecific variation in secondary chemistry among neighbouring plants is important in determining the structure of the associated insect community and positively affects plant performance.
authors.affiliation: Evolution, Ecology and Genetics Division, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bustos-Segura
authors.affiliation: Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands.
authors.forename: Erik H
authors.initials: EH
authors.lastname: Poelman
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Reichelt
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands.
authors.forename: Rieta
authors.initials: R
authors.lastname: Gols
mesh_terms: D000818:Animals; D001937:Brassica / Q000737:chemistry* / Q000254:growth & development*; D005961:Glucosinolates / Q000378:metabolism*; D060434:Herbivory; D007313:Insecta / Q000502:physiology*
chemical_list: D005961:Glucosinolates
keywords: 
  Brassica
  ; Associational resistance; biodiversity-ecosystem function; chemical polymorphism; community genetics; glucosinolates; herbivory; plant diversity; plant-neighbour interactions; trophic cascades