Conifer Bole Utilization by Wood-Boring Beetles in Western Oregon

1989

S. 943-947

3 Abb., 1 Tab., 21 Lit. Ang.

Unselbständiges Werk

200088320

We studied wood excavation by scolytid and cerambycid beetles in decomposing boles of four conifer species during the first two years on the ground in western Oregon. Colonization density and gallery volumes were mesured in experimental boles (0.5 m diameter x 5 m length) of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.) , Pacific silver fir (Abies amabilis (Dougl.) Forbes), and western red cedar (Thuja plicata Donn). Ambrosia beetles (Coleoptera: Scolytidae) colonized boles only during the 1st year and were essentially restricted to Douglas- fir and western hemlock (removing 0.2% of the sapwood volume). Bark beetles (Coleoptera: Scolytidae) colonized boles only in the 1st year, primarily in Douglas-fir and Pacific silver fir (removing 7-8% of the phloem surface area) . Wood borers (Coleoptera: Cerambycidae) excavated an additional 2.3% of the phloem surface area of Pacific silver fir in the 1st year and continued to excatae all species except Douglas-fir during the 2nd year. Consequences for the decomposition process are discussed.