Conservation status of native tree species in British Columbia

Abstract We assess the conservation status of all tree species in order to identify conservation gaps and prioritize genetic conservation efforts. A thorough assessment would consider genetic variation in each species across the species range, but for most tree species, such information is simply not available. For this reason, we used spatial variation associated with Biogeoclimatic Ecosystem Classification zones (BEC zones) representing different macroclimates as a proxy for adaptive genetic variation. We re-assessed the 2005 conservation status calculated in this manner using updated datasets collected in 2017, considered both in situ and ex situ conservation, and used an adjusted criterion for small-stature tree species. Results of our gap analysis revealed that overall, the native tree species in 89% of the conservation units (defined as species-by-biogeoclimatic-zone combinations) were well protected in situ. Of the 43 native tree species in the province, 12 species had conservation gaps in one or more biogeoclimatic zones. When in situ and ex situ conservation were considered jointly, the overall percentage of conservation units that were adequately protected improved to 91%. Needs for additional ex situ collections or in situ protection are discussed in terms of both BEC zones and individual species. In most cases, we recommend seed collection as the most feasible short-term option to cover gaps in protected area coverage.