Monday, December 10, 2007 - 10:29 AM

Terrestrial arthropod community resilience to a catastrophic event in Pacific Northwest poplar plantations

R. Andrew Rodstrom, and John J. Brown, Washington State University, Entomology, Washington State University, Dept. of Entomology, Pullman, WA

Terrestrial arthropod communities are an integral part of a well functioning ecosystem. This community can often be an indicator of the overall health of an area. When hybrid poplar plantations are harvested, this acts as a catastrophic event within this ecosystem. This project investigated the terrestrial arthropod community within a hybrid poplar plantation and its response to the planned catastrophe of harvest. Arthropod communities were surveyed in pre- and post-harvest stands along with several intermediate age classes primarily using pitfall traps. Temperature data was also recorded both above and below ground in the communities to try and quantify potential abiotic differences between the different communities. We hypothesized that epigeal arthropod community composition, based on the Shannon-Weiner diversity index, of the post-harvest and younger communities would not resemble that of the pre-harvest and older communities. Our results indicate that there is a strong response to both season and harvest within the terrestrial arthropod communities. In addition, we show that the post-harvest community quickly recovers to resemble that of the older and pre-harvest communities. Overall the most common species present in both communities was Calathus ruficolis (Coleoptera: Carabidae). This monospecific dominance is most prevalent in the fall, with spring and summer showing greater evenness. We also show that temperatures mirror the community’s quick return to pre-harvest species diversity levels.

Species 1: Coleoptera Carabidae Calathus ruficollis