IMC Colloquium Series: "Linking freshwater biodiversity to ecosystem stability and function"

Abstract

This talk will present two related research directions focused on quantifying the causes and consequences of freshwater biodiversity. First, I will examine how diversity contributes to stability using studies of Pacific salmon in large western North American watersheds, such as the Snake, Skeena, and Fraser. In theory, diversity can increase stability via the portfolio effect, whereby asynchronous dynamics of assets can buffer the aggregate. Financial portfolio theory can offer a quantitative framework to apply to ecological systems, such as salmon. Migratory salmon exhibit striking population diversity, with a diverse array of life-history adaptations. This salmon population diversity can lead to increased stability of catches that integrate across multiple populations. In the Snake River, a more impacted large watershed in the United States, our recent research uncovered insidious biodiversity loss, where salmon populations have not decreased in number, but have decreased in their response diversity, thereby compromising stability. Second, I will investigate how freshwater biodiversity contributes to key ecosystem processes such as the cycling of nutrients such as nitrogen or phosphorus. Through linking large datasets on fish and invertebrate communities with trait-datasets, my collaborator and I seek to map and illuminate patterns of biodiversity-ecosystem function. Together, this research provides insight into the importance of freshwater biodiversity.