Effects of post-fire logging on plant communities in western Montana

Little scientific information is available on the ecological effects of salvage logging following wildfires in the northern Rockies. In other regions regeneration failures, invasions of exotic weeds and changes in plant communities have resulted from post-fire logging. We were interested in how logging technique and site characteristics influence stand development and biodiversity patterns following disturbance. Monitoring plots were established in five study areas in western Montana and northern Idaho to evaluate the initial effects of post-fire logging, and a set of older plots was re-measured to look at longer-term effects. In all cases natural forest regeneration was successful within two years following logging, although tree densities varied according to harvest and yarding technique. Ten years following logging we were still able to detect the influence of logging on vegetation lifeform development, primarily where tractor yarding was used. Grasses most often dominated sites with heavy soils disturbance. Shrubs declined in cover even 10 years after treatment. We found little evidence of noxious or even exotic species invading logged sites. Community analysis of vegetation suggests that dry sites on south or southwest exposures may be more sensitive to logging related disturbances than more mesic sites. In most cases we found vegetation to be resilient to logging treatments.