Spatial location dominates over host plant genotype in structuring an herbivore community

• Published in: Ecology (Durham) 2010-09, Vol.91 (9), p.2660-2672
• Main Authors: Tack, Ayco J. M, Ovaskainen, Otso, Pulkkinen, Pertti, Roslin, Tomas
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; community genetics; Community structure; Connectivity; data collection; Demography; Ecological genetics; Ecosystem; Feeding Behavior; Finland; Flowers & plants; Fundamental and applied biological sciences. Psychology; General aspects; Genotype; Genotype & phenotype; genotype-environment interaction; Genotypes; Herbivores; Host plants; Insect communities; Insecta; Insecta - physiology; Insects; intraspecific genetic variation; Invertebrates; landscapes; metacommunity; Phytophagous insects; Plant ecology; plant traits; plant-insect interactions; Plants; Quercus - genetics; Quercus robur; spatial context; spatial scale; species diversity; surveys; Synecology; trees
• ISSN: 0012-9658; 1939-9170
• DOI: 10.1890/09-1027.1

Recent work has shown a potential role for both host plant genotype and spatial context in structuring insect communities. In this study, we use three separate data sets on herbivorous insects on oak ( Quercus robur ) to estimate the relative effects of host plant genotype ( G ), location ( E ), and the G × E interaction on herbivore community structure: a common garden experiment replicated at the landscape scale (~5 km 2 ); two common gardens separated at the regional scale (~10 000 km 2 ); and survey data on wild trees in various spatial settings. Our experiments and survey reveal that, at the landscape scale, the insect community is strongly affected by the spatial setting, with 32% of the variation in species richness explained by spatial connectivity. In contrast, G and G × E play minor roles in structuring the insect community. Results remained similar when extending the spatial scale of the study from the more local (landscape) level to the regional level. We conclude that in our study system, spatial processes play a major role in structuring these insect communities at both the landscape and regional scales, whereas host plant genotype seems of secondary importance.