A proposed Important Plant Area as a tool for conserving threatened plants and habitats in the Redberry Lake Biosphere Region, Saskatchewan

Résumé

We applied the Important Plant Area (IPA) framework to identify a high conservation value site containing threatened plants and habitats in the Redberry Lake Biosphere Region (RLBR), Saskatchewan. The proposed IPA, named Redberry Lake Flats, lies in the buffer zone of the RLBR and overlaps with the Redberry Lake Migratory Bird Sanctuary and Important Bird Area, highlighting the strong ecological connectivity of the terrestrial and aquatic landscapes. From 2010 to 2025, we conducted intensive field studies in the 115.6-ha site, documenting 190 vascular plant species in 52 families and 128 genera. This floristic richness is concentrated within a mosaic of saline shorelines, marshes, calcareous marl fens, wet meadows, grasslands, and aspen woodlands mixed with shrublands. We discovered 12 vascular plant species of conservation concern at the subnational (provincial), national, and global levels. Primary threats to rare plants and habitats in the study area include hydrological alteration, intensive grazing and trampling, and successional overgrowth. The exceptional floristic richness of the site, the co-occurrence of multiple threatened plants, and distinct marl–fen habitats satisfy four of IPA’s qualification criteria. Hence, we recommend IPA designation for the Redberry Lake Flats site, targetting hydrology-aware management and continuous monitoring to maintain high plant diversity and habitat integrity.