Applications of Dispersal Diversity on Food Web Stability Through a Synthesis of Current Literature and Observational Study

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

The Biology of Vasopressin

Vasopressins are evolutionarily conserved peptide hormones. Mammalian vasopressin functions systemically as an antidiuretic and regulator of blood and cardiac flow essential for adapting to terrestrial environments. Moreover, vasopressin acts centrally as a neurohormone involved in social and parental behavior and stress response. Vasopressin synthesis in several cell types, storage in intracellular vesicles, and release in response to physiological stimuli are highly regulated and mediated by three distinct G protein coupled receptors. Other receptors may bind or cross-bind vasopressin. Vasopressin is regulated spatially and temporally through transcriptional and post-transcriptional mechanisms, sex, tissue, and cell-specific receptor expression. Anomalies of vasopressin signaling have been observed in polycystic kidney disease, chronic heart failure, and neuropsychiatric conditions. Growing knowledge of the central biological roles of vasopressin has enabled pharmacological advances to treat these conditions by targeting defective systemic or central pathways utilizing specific agonists and antagonists