Identifying rare species of songbirds in managed forests: application of an ecoregional template to a boreal mixedwood system

摘要

Foresters are under increasing national and global pressure to demonstrate that forestry activities are ecologically sustainable. One aspect of this is maintenance of current biodiversity on forest management areas. This is problematic where rare species are concerned, due to a paucity of information on which to base management decisions, and potential difficulties in monitoring such species. Generally, species with narrow geographic distribution and high habitat specificity are rare and are most at risk due to habitat change. We present a method of identifying rare species found in commercial habitat types that may be at risk due to forestry activities. We also introduce the concept of temporal rarity into a systematic classification system. We then apply this system to data on songbirds from the boreal mixedwood ecoregion in Alberta, Canada. We identified an initial list of 33 species that were rare based on a rank abundance plot. We then removed species from the list whose geographic ranges within the ecoregion were peripheral and that were more abundant in non-commercial habitat types. We added species that were abundant in our year of sampling but were rare in most other years and flagged species that were irruptive or hard to detect. Finally, we evaluated the conservation priority of the remaining 18 species using three criteria: (1) those that were specialists on habitats that will be reduced or altered by forestry, (2) those already listed as sensitive, and (3) those with restricted continental ranges that overlapped substantially with the focal ecoregion