Using insect responses to anthropogenic disturbance to improve land management and conservation planning decisions

Conservation biology is an application of science to solving conservation problems. The goal of conservation biology is to provide the principles and the tools to preserve biological diversity, which can range from preserving genetic diversity within species, to preserving many species within a given region, to preserving even the ecological functions and ecosystem services that species provide. Conservation biology is used to inform two elemental issues: resource management and reserve design. In this dissertation, I present a case study of urbanization effects on ants and their associated ecosystem services in the Lake Tahoe basin that informs resource management and a case study of an imperiled butterfly species in disjunct wet meadows in the Great Basin that informs reserve design. In the first case study, I examined the effects of urban land development in the Lake Tahoe basin on ant community structure and found that ant species richness, total abundance, and the abundance of aerator ants peaked at intermediate levels of development, while generalist ants had an opposite pattern of abundance and decomposer ants decreased and compiler ants increased with increasing land development. I also found that these service-providing groups of ants were particularly sensitive to changes in dead wood removal and exotic plant invasions. Declines in abundance of ant service-providing units provide evidence that ecosystem provisions, such as water infiltration, are diminished at sites subject to greater levels of urbanization. Thus, these data indicate that the two major environmental goals at Lake Tahoe, improving lake clarity and reducing forest fuel loads, could be advanced from focused attention on aerator ants and the water infiltration services that they provide. In the second case study, I examined patterns of habitat variability of the imperiled silverspot butterfly (Speyeria nokomis carsonensis) to determine whether determinants of occupancy differed between habitat types and to determine how the inclusion of this sort of habitat-specific data affected an optimal reserve design for the species. The immediacy of conservation demands often forces conservation planners to proceed with conservation actions with incomplete habitat data, which may lead to misguiding appropriate conservation actions. I observed a system with apparent habitat types within which the silverspot occurred. I found that habitat features differed substantially between habitat types and that the determinants of patch occupancy concomitantly differed between habitat types. Given that conservation planners may design reserve networks for an imperiled species only based on data that are immediately obtainable, such as patch area and isolation (i.e. 'traditional'), I examined how reserve systems differ between a 'traditional' approach and a habitat-specific approach. I found extremely differences in which sites were selected for inclusion in an optimal reserve system between the two approaches, thereby demonstrating that by only incorporating area and isolation into a reserve design can greatly misrepresent an appropriate reserve network for an imperiled species.