Not all non-natives are equally unequal: reductions in herbivore β-diversity depend on phylogenetic similarity to native plant community.
Effects of host plant α- and β-diversity often confound studies of herbivore β-diversity, hindering our ability to predict the full impact of non-native plants on herbivores. Here, while controlling host plant diversity, we examined variation in herbivore communities between native and non-native plants, focusing on how plant relatedness and spatial scale alter the result. We found lower absolute magnitudes of β-diversity among tree species and among sites on non-natives in all comparisons. However, lower relative β-diversity only occurred for immature herbivores on phylogenetically distinct non-natives vs. natives. Locally in that comparison, non-native gardens had lower host specificity; while among sites, the herbivores supported were a redundant subset of species on natives. Therefore, when phylogenetically distinct non-natives replace native plants, the community of immature herbivores is likely to be homogenised across landscapes. Differences in communities on closely related non-natives were subtler, but displayed community shifts and increased generalisation on non-natives within certain feeding guilds.
Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716-2103, USA.|Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA.
Karin T
http://orcid.org/0000-0002-9302-6802
KT
Burghardt
Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716-2103, USA.
Douglas W
DW
Tallamy
D000818:Animals; D001181:Arthropods; D044822:Biodiversity; D005247:Feeding Behavior; D060434:Herbivory; D058865:Introduced Species; D010802:Phylogeny; D010944:Plants / Q000145:classification
Beta diversity; feeding guild; herbivore; host specificity; insects; managed landscapes; native plant; non-native plant; spatial scale