| This thesis spans diverse topics from across the discipline of ecology. In Part I, I address questions of pressing importance in environmental policy and conservation biology. Specifically, I analyse the meeting of ecology and economics in the subject of protected area design. Part II reconsiders the role of dispersal in population and community ecology in light of recent empirical evidence, evidence that challenges fundamental tenets of our understanding of spatial dynamics.; Seemingly intangible ecosystem characteristics that preoccupy ecologists, like ecosystem stability and the responsiveness of populations to environmental variation, have quantifiable economic values. In Chapter 2, I show how to derive these values and how their consideration should change environmental decision-making. To illustrate these concepts, I employ a simple reserve design model.; Atlantic tuna fisheries are extremely valuable and their management excites impassioned debate among stakeholders. Western Atlantic bluefin tuna enter the Gulf of Mexico region to spawn. During the spawning season, bluefin are caught as incidental catch by Gulf longline fishermen targeting yellowfin tuna. In Chapter 3, I use economic principles to examine how this fisheries interaction should be managed.; Understanding how populations and communities respond to habitat fragmentation is of critical importance if we are to restrict future losses of biodiversity, and requires understanding how dispersal patterns are affected by the spatial configuration of remaining habitats. Almost all spatial dynamic theory concentrates on random dispersal, in which movement rates are assumed to be constant and do not depend on the state of the individual or its environment and movement directions are unbiased. I examine the neglected dispersal component of directed movement in Chapters 4 and 5, in which dispersal is envisioned as a phenotypic response by individuals to varying environmental conditions, one that is conditional and directional. |
