Master's student University of Sherbrooke BROSSARD, Quebec, Canada
Background/Question/Methods
With the rapid decline in freshwater biodiversity and growing disturbances in adjacent terrestrial systems (deforestation, wetland destruction, etc.), the assessment and monitoring of biodiversity within these systems is essential for implementing appropriate conservation measures. Watersheds represent a fundamental unit in the interconnected aquatic-terrestrial ecosystem, and despite growth in the number of cross-ecosystem studies, there is still a lack of research investigating the biodiversity of the coupled watershed system where both aquatic and terrestrial species are examined. Herein, we are attempting to bridge this gap by utilizing various biodiversity indices to identify and map watershed biodiversity (aquatic and terrestrial) hotspots across different Canadian ecozones. We are investigating the relationship between aquatic and terrestrial diversity, as well as the relationship between land use and biodiversity metrics. Due to the national scale of this project, we will consider variability among watershed as well as among different Canadian ecozones. For now, we are focusing our biodiversity analyses in the aquatic realm by considering phytoplankton and zooplankton taxa collected and identified by the Canadian NSERC Lake Pulse Network whereas the terrestrial species consist of birds and vegetation which are being acquired through public online databases and remote sensing techniques.
Results/Conclusions
Given the range in quality and distribution of data available in online public databases for birds, we first began with a pilot study to evaluate the coherency between the Ebird and the North American Breeding Bird Survey (BBS) datasets. Focusing on species richness per year data (from 2005-2020) across 10 randomly selected Lake Pulse watersheds, we found that the average standard deviation was 10.75% for BBS and 36.76% for eBird. Additionally, eBird ratios of species richness per number of individuals sampled per year displayed signs of observer biases, where certain watersheds displayed greater abundances of birds sampled. BBS was ultimately selected due to the consistency in sampling effort and the adoption of a standardized methodology across tested watersheds. Based off this selection, we then calculated the relationship between aquatic species diversity (zooplankton and phytoplankton) and bird species (based on BBS) and detected a modest but non significant positive Pearson’s correlation of r(8) = 0.27, p = 0.47. As we scale up our results to hundreds of Canadian watersheds, we will have the opportunity to add substantial statistical power to our analyses as well as consider other sources of heterogeneity including variation associated with specific environmental conditions or among ecozones.
