Madrone duff and the natural regeneration of Douglas-fir.

Abstract

Excellent natural regeneration of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) often occurs under canopies of Pacific madrone (Arbutus menziesii Pursh), but the effects of madrone duff on regeneration are poorly understood. A field experiment was conducted in a thinned Douglas-fir stand in southwestern Oregon to see if madrone duff benefits natural regeneration or reduces the cover of species that compete with Douglas-fir. No significant differences in conifer regeneration and growth or in the cover of competing species occurred among seedbeds of madrone duff, conifer duff, and mineral soil during 10 growing seasons. Douglas-fir regeneration may be affected less by madrone duff than by other influences of madrone trees.

Citation

Minore, Don. 1987. Madrone duff and the natural regeneration of Douglas-fir. Res. Note PNW-RN-456. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 8 p