Doug Tallamy lecture: "Are 'alien' plants 'bad'?"

Doug Tallamy is Professor of Entomology and Wildlife Ecology at University of Delaware, and author of the popular text "Bringing Nature Home: How Native Plants Sustain Wildlife in our Gardens."

The expense of fighting alien plant invasions and the unpopularity of restricting the sale of ornamental invasives have motivated several public figures to question the wisdom of continuing to battle invasive plants. After all, they argue, if an alien plant helps a particular butterfly, bird, or bee, why not embrace it? Using data from several studies, Tallamy answers this and related questions, showing that we can determine the overall impact of alien plants on our ecosystems only by comparing what is gained from their use with what is lost when they replace native plant communities.  Introduced plants are not the ecological equivalents of the native plants they displace because they do not support the diverse and stable food webs that run our ecosystems.  Exchanging plants that support all of our animal diversity for plants that support only a few species is ecologically indefensible.