Evaluating the diversity, distribution patterns and habitat preferences of Carex species (Cyperaceae) in western Canada using geospatial analysis.

Abstract

Sedge (Carex) is a highly diversified genus of vascular plants with high species diversity in cold-temperate areas of the Northern Hemisphere. In Canada, 313 species of Carex are documented with 105 species in Saskatchewan, making it the largest genus of vascular plants in this Province. Research on the distribution and ecology of sedges in Saskatchewan is extremely limited. This study aims to find the distribution patterns of Carex species and identify their habitat preferences relative to environmental conditions in Saskatchewan through the application of GIS spatial analysis tools. Data on specimen-based occurrences of Carex species were collected, validated and consolidated from the Flora of Saskatchewan Association (FOSA) and analysed along with Carex datasets mobilised by the Global Biodiversity Information Facility (GBIF), resulting in 2655 individual records of occurrences. Our research includes seven environmental variables to explore relationships between Carex species and environment. The study produced comprehensive spatial maps and graphs illustrating species occurrences, species richness and diversity hotspots. It was found that Carex species have a diverse habitat preference strongly associated with temperature and precipitation and, to a lesser extent, soils. The species occurrences are mostly concentrated in the Boreal Plain and Prairie ecozones of the Province. Notably, species richness peaked in the central part of Saskatchewan in areas with moderate elevation and temperature and high precipitation. This integrative analysis emphasises the need for region-specific assessments to effectively manage and preserve biodiversity.