Soil invertebrates of American Samoa

Vargo, Donald

Soil invertebrates are largely responsible for building soil into the fertile matrix necessary for plant life, and, therefore, all animal life. Yet many of them, especially in the tropics and the southern hemisphere, are unknown. This is the first study to identify and quantify soil invertebrates in American Samoa. Pitfall traps and Berlese-Tullgren funnel extractions of soil cores were used between February 1998 and February 1999 to collect arthropods, gastropods, and turbellaria on three volcanic islands of the eastern Samoan archipelago in the south-central Pacific. The major groups collected were Acari, Amphipoda, Formicidae, and Diptera. A small number of these, and specimens from less common groups, were identified to species. The soil invertebrate composition was found to be largely a collection of species common throughout the South Pacific, usually dispersed through human commerce. Intense competition among these recently introduced species for niches relinquished by now-defunct, specially adapted indigenous species may be responsible for their much-reduced population densities, which in turn probably reduces the soil nutrient cycling efficiency for these islands.

Soil invertebrates of American Samoa

Series