title: Tree phylogenetic diversity promotes host-parasitoid interactions.
abstract: Evidence from grassland experiments suggests that a plant community's phylogenetic diversity (PD) is a strong predictor of ecosystem processes, even stronger than species richness per se This has, however, never been extended to species-rich forests and host-parasitoid interactions. We used cavity-nesting Hymenoptera and their parasitoids collected in a subtropical forest as a model system to test whether hosts, parasitoids, and their interactions are influenced by tree PD and a comprehensive set of environmental variables, including tree species richness. Parasitism rate and parasitoid abundance were positively correlated with tree PD. All variables describing parasitoids decreased with elevation, and were, except parasitism rate, dependent on host abundance. Quantitative descriptors of host-parasitoid networks were independent of the environment. Our study indicates that host-parasitoid interactions in species-rich forests are related to the PD of the tree community, which influences parasitism rates through parasitoid abundance. We show that effects of tree community PD are much stronger than effects of tree species richness, can cascade to high trophic levels, and promote trophic interactions. As during habitat modification phylogenetic information is usually lost non-randomly, even species-rich habitats may not be able to continuously provide the ecosystem process parasitism if the evolutionarily most distinct plant lineages vanish.
authors.affiliation: Chair of Nature Conservation and Landscape Ecology, Faculty of Environment and Natural Resources, University of Freiburg, Tennenbacher Strasse 4, 79106 Freiburg, Germany michael.staab@nature.uni-freiburg.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Staab
authors.affiliation: Geobotany and Botanical Garden, Institute of Biology, Martin Luther University of Halle-Wittenberg, 06108 Halle (Saale), Germany German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Bruelheide
authors.affiliation: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany Department of Community Ecology (BZF), Helmholtz Centre for Environmental Research UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Saale), Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Durka
authors.affiliation: Department of Community Ecology (BZF), Helmholtz Centre for Environmental Research UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Saale), Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Michalski
authors.affiliation: Geobotany and Botanical Garden, Institute of Biology, Martin Luther University of Halle-Wittenberg, 06108 Halle (Saale), Germany German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany Department of Computer Science, Martin Luther University of Halle-Wittenberg, Von-Seckendorff-Platz 1, 06120 Halle (Saale), Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Purschke
authors.affiliation: Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: Chao-Dong
authors.initials: CD
authors.lastname: Zhu
authors.affiliation: Chair of Nature Conservation and Landscape Ecology, Faculty of Environment and Natural Resources, University of Freiburg, Tennenbacher Strasse 4, 79106 Freiburg, Germany.
authors.forename: Alexandra-Maria
authors.initials: AM
authors.lastname: Klein
mesh_terms: D000818:Animals; D044822:Biodiversity; D065928:Forests; D006790:Host-Parasite Interactions; D006927:Hymenoptera / Q000469:parasitology*; D010802:Phylogeny; D014197:Trees / Q000145:classification*
keywords: Gutianshan National Nature Reserve; ecological networks; environmental gradients; parasitism; species interactions; trap-nesting Hymenoptera