Doug Tallamy
Friday, October 17, 2008 - 10:30-11:00
Alien plants are rapidly replacing native species in both natural and anthropogenic landscapes throughout North America. Large-scale replacement of native vegetation has a number of biotic and abiotic consequences but one that has received little empirical attention is the effect of alien plant species on insect herbivores and the insectivores that eat them. Theory predicts that specialists should be unable to grow and reproduce on plants with which they share no evolutionary history. Because the majority of insect herbivores are thought to specialize on one or a few plant lineages, alien invasions should reduce local biodiversity, which, in turn, is predicted to reduce ecosystem stability and productivity. Four studies will be presented which demonstrate that native plants support significantly more species of native insect herbivores, significantly more insect biomass, and significantly larger communities of insectivores than do alien plants. These results provide useful criteria for plant selection in managed and unmanaged landscapes that can assist restoration ecologists, landscape architects and designers, land managers, and homeowners raise the carrying capacity of particular areas.
Keywords: INSECT HERBIVORES, INSECTIVORES, BIODIVERSITY, ALIEN PLANTS