When the prairie varies: the importance of site characteristics for strategising insect conservation


Chris Looney, 1220 Division St. NW, Olympia, WA 98502, USA. E-mail: looneywa@gmail.com


Abstract.  1. The bunchgrass prairies of the Palouse region in eastern Washington state and adjacent Idaho have been mostly converted to agriculture in the past century. Prairie habitat currently exists only on small remnants scattered across the landscape.

2. The invertebrate fauna of these habitat remnants is poorly known, both in terms of species diversity and community composition.

3. Baited pitfall traps were used to sample carrion-attracted beetles during June and July of 2003 from high-quality prairie remnants of varying size and soil characteristics.

4. Twenty-three beetle species in five families were found. Species richness and Shannon-Wiener diversity were not significantly correlated with habitat area or perimeter–area ratio.

5. Beetle abundance and community structure were strongly correlated with soil characteristics. Deeper, loessal soils had greater overall beetle abundance than shallower, rocky soils, although some species were more frequently captured in shallower, rocky soil sites.

6. Conservation plans emphasising only remnant size and condition do not sufficiently capture variability in insect communities across Palouse prairie remnants.