Results of fungal inoculation treatments as a habitat enhancement tool in the East Kootenay Region of British Columbia: 2007-2013.
Wildlife trees provide critical nesting, denning, roosting, and feeding habitat for more than 70 species of birds, mammals, and amphibians in British Columbia, including some species that are considered at risk provincially and federally. Depending on the age, condition, and disturbance type and history of the forested landscape, wildlife trees can be in short supply in some areas. This is the case in parts of the Columbia River valley in the East Kootenay region of British Columbia, where wildlife tree enhancement treatments using inoculation with native heart-rot decay fungi and mechanical stem modifications have been conducted since 2007 to increase local habitat supply. Thirteen properties in this region that are managed by several partners for ecosystem restoration, biological diversity conservation, and wildlife habitat maintenance or enhancement were selected for wildlife tree treatments using fungal inoculation between 2007 and 2013. The overall project goals were to enhance wildlife tree habitat in areas that currently lack wildlife trees, and to increase the abundance of wildlife trees in areas that have high habitat capability for Lewis's Woodpecker (Melanerpes lewis), Flammulated Owl (Psiloscops flammeolus), and other cavity-dependent wildlife. In total, 369 trees (217 Douglas-fir, 139 ponderosa pine, and 13 western larch) were inoculated and mechanically modified to enhance or create wildlife tree habitat in the treatment areas. All trees were live and appeared healthy prior to treatment. To determine if the inoculation and mechanical modification treatments were producing internal decay, a limited destructive sampling program was conducted in 2010 at the Hoodoo-Hofert property using trees that had been inoculated in 2007; the program was repeated in 2013 at the Dutch Findlay property using trees that had been inoculated in 2010. Heart-rot decay in its early to moderately advanced stages occurred within 3 years post-treatment in some of the sampled trees. This timeframe is very rapid compared to natural heart-rot decay dynamics, which often require more than 100 years from initial tree wounding for significant decay to become established, and suggests that the revised drilling and girdling techniques employed during the latter part of the project period improved the efficacy of the inoculation treatments. The results of this study shed new light on ways to improve the efficacy and application of the inoculation techniques, and are consistent with other assessments of fungal inoculation trials in British Columbia, Washington State, and Oregon. Recommendations for improving the efficacy and application of fungal inoculation and mechanical stem modifications as a useful wildlife habitat enhancement tool are also discussed. Fungal inoculation treatments can provide accelerated creation, enhancement, and recruitment of wildlife trees in areas where there is a shortage of such habitat, and where management goals include increasing wildlife habitat supply and restoring old forest-like structural characteristics. We recommend continued effectiveness monitoring of inoculated trees to verify the presence and extent of internal decay and subsequent use by cavity-dependent wildlife over time.