The Rio Grande National Forest (RGNF) includes some of the most important Canada lynx habitat in Colorado. Approximately 85 percent of the 218 lynx reintroduced to Colorado from 1999-2007 were released on the RGNF. Lynx depend on spruce-fir forests with dense understories across their distribution. However, by 2013, a spruce beetle outbreak killed approximately 85 percent of mature spruce in the subalpine cover types on the RGNF, and these impacts will be more prevalent in the future with climate change. Biologists are in the difficult position of being required to evaluate the impact of timber salvage to this federally-listed species without a scientific basis to support their decisions.
The Rocky Mountain Research Station, in cooperation with the RGNF, the USFS Rocky Mountain Region, Colorado Parks and Wildlife, and Montana State University, is currently investigating the resource selection and movements of Canada lynx that occupy spruce-beetle impacted forests. The project's objectives include:
1) determine seasonal changes in resource-use of Canada lynx in spruce beetle-impacted forests of southern Colorado;
2) map forest characteristics across spruce-beetle impacted landscapes relative to proposed timber salvage; and
3) document the relative abundance of snowshoe hares, the primary prey of lynx, in relation to forest structures found in spruce-beetle outbreaks.
In 2015-2016, the team instrumented lynx with GPS collars to plot their movements and resource-use patterns in beetle-impacted forests. Using this technology ,the team documented that lynx used spruce-beetle impacted forests during winter and summer, including females that denned and produced kittens. Using remote sensing and by sampling more than 450 vegetation plots, the research partners have mapped the forest overstory and understory of beetle-impacted forests. To develop stand-level silvicultural prescriptions, the team is currently sampling forest attributes at GPS locations and random sites to understand lynx habitat selection in beetle-impacted forests.
This research will inform stand and landscape-level silvicultural prescriptions relative to proposed timber salvage in relation to lynx conservation. This issue is highly relevant across the West as insect-impacts to forests will increase with climate change.