2012 Ka‘ahahui o ka Nāhelehele Dryland Symposium

Animals play direct roles in the reproduction of most tropical forest plants through pollination, seed dispersal, and seed predation. Following human colonization of the Hawaiian Islands, most of the native fauna in the islands' forests has become rare, extirpated or extinct, and a diverse array of alien species has invaded and proliferated. As a result, plants today are interacting with very different animal communities than they were during most of their evolutionary history, and the implications for plant reproduction are poorly understood. Dr. Don Drake, University of Hawai’i at Hilo, discusses the complex roles alien animals play in Hawaii’s dryland forests – and highlights expected and unexpected roles that alien animals play in reproduction of Hawaiian forest plants. For example, honeybees are important flower visitors in many forest types, and may now be the only flower visitors for some native plant species. Japanese white-eyes may be effective pollinators of some plant species rarely visited by native birds, but they are nectar robbers of others. Japanese white-eyes and Kalij pheasants disperse seeds of some native plants that are no longer dispersed by native birds. Ship rats are seed predators of some species, but disperse seeds of others. The roles of these alien animals are further complicated by the fact that they are involved in the reproduction of invasive alien plants and may be competing for plant resources with native animals. A thorough understanding of the roles of alien species in plant reproduction is necessary if we are to anticipate and avoid unexpected effects that may arise following their removal.

This talk was presented at the 2012 Nahelehele Dryland Forest Symposium: "Connections" on February 24th, 2012 in Kailua-Kona, Hawaii. The symposium highlight dryland forest ecology and restoration efforts in Hawai‘i.