Document: JON-3-65-22

Spatial dependence of arboreal beetles in beech-maple and mixed mesophytic forest associations of Ohio.

GERING, J.C.* and T.O.CRIST

Miami University, Oxford, OH 45056 ¹

Abstract:
We investigated the spatial dependence of arboreal beetles in beech-maple and mixed mesophytic forest associations in Ohio using grid-based sampling and an insecticide fogging technique. Beetles were collected in early July 1999 from the beech-maple forest association (Hueston Woods State Park, Preble Co., OH) by fogging 35 points located in a 450 x 500-m hexagonal grid. In the mixed mesophytic forest association (Shawnee State Forest, Adams Co., OH), sampling took place in late August 1999 at 21 points in a 350 x 450-m hexagonal grid. The grid 'points' consisted of nine 0.5-m^2 collecting funnels. Three points in each grid had nine groups of funnels (81 total funnels) separated by distances of 10-15 m. These 'clusters' were used to assess fine-scale spatial variation in beetle abundance within each forest association. We collected a total of 1,635 beetles from the beech-maple forest and 2,071 beetles from the mixed mesophytic forest. Based on findings regarding host-tree associations of beetles, we predicted that spatial dependence would occur at finer spatial scales in the mixed mesophytic forest because the spatial turnover of tree species is much higher in this forest association. However, semivariance analysis detected spatial dependence in beetle abundance at lags up to 21-30 m in both forest associations. The similarity in spatial dependence between the forest associations may indicate common responses to forest structure. For instance, the distances of spatial dependence (21-30 m) roughly approximate the diameter of a tree crown. As tree crowns merge into one another, changes may occur in leaf area, canopy volume, and other attributes which affect beetle abundance.

Keywords: spatial dependence, beetles, forest, Ohio

This abstract is being presented at: 3:30 PM in session:
ANIMAL ECOLOGY