Great Basin Naturalist


This study was designed to characterize arboreal arthropod community structure in an early successional coniferous ecosystem. We sampled six-year-old snowbrush (Ceanothus velutinus Dougl. ex Hook) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) at the H. J. Andrews Experimental Forest in western Oregon during 1982. The arthropod fauna was dominated in terms of densities by psyllids and aphids on snowbrush and by adelgids and cecidomyiids on Douglas-fir. Significant associations among taxa, e.g., positive correlation between aphids and ants, indicated trophic interactions or similar responses to host conditions. Significant seasonality was observed for individual taxa and for the community, reflecting the integration of individual life-history patterns. Significant spatial pattern (patchiness) in the arthropod community may reflect the influence of faunas on individual plants within neighborhoods and/or the influence of ant foraging patterns.