accepted

Functional and phylogenetic dissimilarity of woody plants drive insect herbivory in highly diverse forests

2013-01-19

2015-02-09

New Phytologist

2013-09-19

The degree of herbivore damage a plant species experiences has been shown to often be affected by the density of conspecific plant neighbors. However, host spectra of many herbivores often comprise a suite of related plant species, and generalist herbivores may even use host plants from a variety of different families. Herbivory might thus be strongly linked to the phylogenetic structure of a plant community, and several patterns would be possible: (1) If host plant use and the plant traits that attract herbivores are phylogenetically conserved, the herbivore damage experienced by a plant species might be the higher the more closely related it is to the remaining species in the community. (2) While this would primarily apply to a scenario with more specialized herbivores, generalist herbivores could also cause higher damage on more distantly related plants if this allows them to avoid high levels of phylogenetically conserved plant defenses in their diet. (3) Phylogenetic effects will ultimately be due to evolutionarily conserved functional traits. However, if the traits that determine host use and herbivore damage are phylogenetically labile, phylogeny would be a weak predictor of herbivore damage. Here, we propose to analyze herbivory patterns of selected tree and shrub species in the CSPs, and relate intraspecific variation in herbivore damage across the 27 study plots to phylogenetic community structure. As the traits determining variation in herbivory need not necessarily show a phylogenetic signal, we also include direct measures of plant functional diversity (based on leaf palatability and defense traits that are relevant for herbivores). This allows us to test whether measures of phylogenetic diversity can complement (or outperform) direct measures of plant functional traits in explaining herbivory patterns across the CSPs, and the results can help to better understand the mechanisms underlying plant diversity-dependent patterns in herbivore damage. We plan to study both community level relationships between herbivory and overall phylogenetic/functional diversity and species-specific herbivory patterns in relation to the mean phylogenetic distance between the respective focal species and all other woody plant species in the forest stands.

Andreas Schuldt, Thorsten Assmann, Helge Bruelheide, Prof., Walter Durka, Stefan Michalski, Oliver Purschke, Martin Böhnke, David Eichenberg, Dr., Wenzel Kröber, Karin Nadrowski, Teng Fang, Anja Hallensleben