Main content area

Stumps fumigated with chloropicrin: effects on surrounding plants

Luoma, D.L., Thies, W.G.
Canadian journal of forest research = 1997 v.27 no.11 pp. 1737-1745
Pseudotsuga menziesii, Phellinus weirii, chloropicrin, stumps, nontarget organisms, clearcutting, vegetation, indicator species, harvesting, species diversity, understory, adverse effects, application rate, biological resistance, Washington
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stumps, both healthy and infected by Phellinus weirii (Murr.) Gilbertson, were fumigated with chloropicrin at a clearcut site on Washington's Olympic Peninsula. Vegetation cover on plots adjacent to treated and untreated stumps was evaluated to determine fumigant effects on vascular plants and moss. Ninety-eight vascular plant species were recorded during the course of the study. Only those species with 40% or greater frequency (14) and mosses were included in the analysis of individual species cover. We found that Trientalis latifolia Hook, may be sensitive and act as an early indicator of chloropicrin effects in the cleancut habitat of this study. Three years following application to stumps, chloropicrin had little or no effect on other surrounding vegetation. The general lack of interaction effects between distance of plot to stump and fumigation treatment leads to the conclusion that the chloropicrin largely stayed in the stumps during the first 3 years following treatment. Effects attributed to harvest methods, study layout, and pretreatment conditions were detected. Species richness decreased with distance from the former stand edge. Higher mean species richness in the control plots was significantly correlated with distance to former stand edge. The results also demonstrate the potential magnitude and legacy of edge effects in forest stands and the need to account for those effects in study design.