Abstract

Dispersal is a key mechanism that allows for spatially separated populations to interact across space and time. Rates of dispersal have been identified as a key factor shaping the stability of ecological communities. Dispersal diversity is the component of diversity that encompasses species dispersal abilities, driven by variation in dispersal-linked traits and condition-dependent movement behaviours. Frameworks that incorporate spatial dynamics often have not considered this source of diversity, opting for simpler methods of accounting for dispersal, but recent theoretical research has pushed for explicit inclusion of dispersal diversity within spatially structured (meta)communities. In my first chapter I reviewed literature that supports the stabilizing role of dispersal diversity and compiled intrinsic and extrinsic sources of variation that could be used to monitor stability in a trophic food web. In chapter two I tested whether local dispersal diversity predicted local community stability in the marine fish metacommunity of the Newfoundland and Labrador shelves, using dispersal trait measurements to quantify dispersal diversity and determine its impact on community stability over time. The results from chapter two support the stabilizing role of dispersal diversity, and that dispersal diversity can be measured applying the same methods as for functional diversity. This research highlights the importance of dispersal diversity for community stability, how dispersal diversity can be measured, and provides direction for future spatial studies on what traits to consider when accounting for dispersal diversity. Incorporating dispersal diversity into spatial models could provide better information to decision makers for managing spatially connected regions.