Timothy Schowalter | 4/1/2008 8:14:01 PM
Data from a National Science Foundation supported long term study of canopy arthropod responses to different forest structures in conifer forests at or near the H.J. Andrews Experimental Forest Long Term Ecological Research (LTER) Site in western Oregon. The four forest types are old-growth Douglas-fir/western hemlock (500 year old), old-growth shelterwood (partially harvested 1980-1990), mature second-growth (fire regenerated forest 150-200 years old) Douglas-fir, and planted Douglas-fir (10-20 year old). Six geographically-intermixed replicates of each stand type were sampled. Canopies were sampled by climbing mature or old-growth trees and bagging 30-40 cm of a foliage-bearing branch (50-100 g) at each of top (within 5 m of top), mid, and lower (5 m from lowest branches) canopy levels of each tree, clipping the branch and sealing the bag. Samples were returned to the lab where all arthropods were tabulated by taxon and plant material dried at 50o C to constant weight. Arthropod abundances were standardized as number per g plant material. Results have been reported in:
Progar, R.A. and T.D. Schowalter. 2002. Canopy arthropod
assemblages along a precipitation and latitudinal
gradient among Douglas-fir Pseudotsuga menziesii
forests in the Pacific Northwest of the United States.
Ecography 25: 129-138.
Schowalter, T.D. and L.M. Ganio. 1998. Vertical and seasonal
variation in canopy arthropod abundances in an old-
growth conifer forest in southwestern Washington.
Bulletin of Entomological Research 88: 633-640.
Schowalter, T.D. 1995. Canopy arthropod community responses
to forest age and alternative harvest practices in western
Oregon. Forest Ecology and Management 78: 115-25.
Schowalter, T.D. 1995. Canopy invertebrate community response
to disturbance and consequences of herbivory in
temperate and tropical forests. Selbyana 16: 41-8.
Data file below support the long term study.