Understory plant diversity in riparian alder-conifer stands after logging in southeast Alaska.

Abstract

Stand structure, tree height growth, and understory plant diversity were assessed in five mixed alder-conifer stands after logging in southeast Alaska. Tree species composition ranged from 7- to 91-percent alder, and basal area ranged from 30 to 55 m2/ha. The alder exhibited rapid early height growth, but recent growth has slowed considerably. Some conifers have been suppressed, but some spruce are now nearly as tall as the overstory alders. The four stands with the most alder had high species richness of shrubs, herbs, ferns, and mosses, but the predominantly spruce stand had slightly fewer species of shrubs and ferns, and considerably fewer herbs. Mixed alder-conifer stands have maintained species-rich understories for 45 years after logging, and stands with conifers and alders of relatively equal stocking contained the largest diameter conifers. Riparian alder-conifer stands maintain plant diversity and also will provide some large-diameter conifers for large woody debris for streams.

Citation

Deal, Robert L. 1997. Understory plant diversity in riparian alder-conifer stands after logging in southeast Alaska. Res. Note PNW-RN-523. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 8 p