Factors influencing growth and flowering of understory plants in conifer stands in Western Washington

Abstract

Managing forest stands to produce wood while also producing other values, such as wildlife habitat, recreation, or special forest products, requires information on forest components not always measured in traditional silviculture studies. For example, some managers may want to predict potential growth rates of herbs, shrubs, and trees in the understory—as these components will determine future forest composition and structure—or may be interested in flowering of plants in forest understories, since berry and seed production are important factors in determining species habitat suitability. We conducted several studies in conifer stands in western Washington to determine the effects of stand and site conditions on (1) response of understory vegetation to changes in overstory density, (2) flowering of selected shrub species, and (3) tree growth in forest understories. Responses of most factors were quite variable and indicate that managers may have to accept a lower level of certainty or invest more in research and monitoring when managing for components of forest stands other than overstory trees. The general results and management implications from the three studies are discussed and a reading list presented.

Citation

Harrington, Constance A.; Buermeyer, Karl R.; Brodie, Leslie C.; Wender, Bryan W. 2002. Factors influencing growth and flowering of understory plants in conifer stands in Western Washington. In: Johnson, Adelaide C.; Haynes, Richard W.; Monserud, Robert A., eds. Congruent management of multiple resources: proceedings from the Wood Compatibility Initiative workshop. Gen. Tech. Rep. PNW-GTR-563. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 159-168.