A Historical-Ecological Approach to Understanding the Effects of Timber Harvest on Wa’uumst (Devil's Club, Oplopanax horridus) in Lax'yip Madii Lii

Industrial land-use has had profound impacts on Indigenous peoples’ homelands throughout Canada. Over the last century, logging practices in British Columbia have severed peoples’ connections to the land-base, creating access challenges and disrupting the availability of important plant resources. Devil’s club (Oplopanax horridus) is an important medicinal plant to communities in northwestern British Columbia, and there are mounting concerns about the impacts of logging on this ethnobotanically salient species. Over the last 70 years, swathes of productive forests throughout Gitxsan homelands have been impacted by the logging industry. Wilp (house) Luutkudziiwus has seen ~12% of their territory of Madii Lii altered by industrial-scale clearcut logging, which has left a mosaic of even-aged cutblocks that have potentially altered devil’s club habitat. To investigate and detail the potential impacts of logging on devil’s club in Madii Lii territory, this research measured devil’s club health and vigour across a chrono-sequence of clearcut-logged sites compared with traditionally managed and unlogged sites in the territory. In addition, Species Distribution Models in conjunction with two different climate change scenarios (SSP245 moderate GHGs and SSP585 high GHGs) were used to predict habitat suitability for devil’s club in Madii Lii and throughout British Columbia to the end of the 21st century. Results suggest that, compared to traditionally managed areas (and controls), extensive logging in the territory negatively impacted the health and vigour of devil’s club, especially the most desirable individuals (with the largest and thickest stems). In addition, the predictive modelling for both climate scenarios suggest that climate change will increasingly impact highquality devil’s club habitat.