Thesis Defence: Characterizing Grassland Connectivity in British Columbia’s Southern Interior

Brittany Adams, supervised by Dr. Mathieu Bourbonnais, will defend their thesis titled “Characterizing Grassland Connectivity in British Columbia’s Southern Interior: A Generic Species Approach” in partial fulfillment of the requirements for the degree of Master of Science in Earth and Environmental Sciences.

An abstract for Brittany Adams’ thesis is included below.

Defences are open to all members of the campus community as well as the general public. Registration is not required for in-person defences.

Abstract

Grasslands are the most fragmented and least protected of all terrestrial biomes, threatening grassland-dependent communities who rely on well-connected habitat to facilitate dispersal, migration, range shifts, and other necessary ecological processes for survival. In British Columbia, Canada, temperate grasslands represent only one percent of the provincial land base, yet they are home to over 30% of the region’s threatened or endangered species. Identifying regions of high connectivity value for grassland-dependent communities in BC has become an important strategy for conserving grassland biodiversity amidst growing anthropogenic pressures. We applied a randomized shortest paths, generic species approach within the ConScape library to characterize the functional connectivity of British Columbia’s southern interior grasslands for a range of grassland-associated species with varying life history traits. We identified patterns of proximity-weighted betweenness (i.e., movement flow) and habitat functionality for each individual generic species and for all generic species combined to quantify both single-species and multi-species connectivity and used these outputs to locate priority grasslands for connectivity. Priority grasslands were large, central, and often occurred adjacent to protected areas, helping to provide core habitat while simultaneously facilitating movement among other habitat patches or protected regions. Functional grassland habitat for multiple species was poorly protected and largely occurred within Crown or privately-owned land, emphasizing the importance of collaborative conservation approaches among stakeholders. Dispersal ability, the degree of grassland specialization, and movement behaviour (θ) all influenced large-scale patterns of movement flow and habitat functionality, suggesting that grassland species vary substantially in how they perceive landscape connectivity. This has important implications for how connectivity can best be preserved for the wider species community. This is the first study to our knowledge that characterizes functional connectivity for multiple grassland-associated species in the southern interior. Despite their high vulnerability and ecological value, temperate grasslands are historically an under-studied biome that requires the development of targeted conservation approaches to preserve connectivity for entire grassland communities. Our research has shown that a generic species approach can be effectively applied to grassland regions that may lack the data or resources to assess connectivity for a sufficient range of focal species.