The effects of spatial and temporal scale on conservation planning and ecological networks in the Central Valley, California

Conservation planning and priority setting requires selection of both a planning area boundary and temporal baseline, or reference condition. This dissertation uses the Central Valley ecoregion of California as the context within which to examine the results of conservation planning decisions that are made using different spatial and temporal baselines.;The second chapter compared potential ecological networks identified at both the regional and local scales in order to illustrate the impact of scale effects on conservation planning We identified a potential regional conservation network for the Central Valley from which we extracted those portions found within five individual counties. We then conducted the same analysis for each of those individual counties. An overlay of the results from the two scales shows a general pattern of large differences in the identified networks. The results suggest that planning efforts at any one scale neglect to include biodiversity patterns and ecological processes that are important at other scales.;The final chapter integrates future land use scenarios with contemporary conservation planning in a subregion of the Central Valley in order to identify future patterns of vulnerability and degradation of an ecological network. We assessed current and projected future impacts from modeled urban growth. The modeled urban growth forecasts were overlaid on the ecological network to identify expected impacts. A threat index was calculated for individual network components and for component clusters, and revealed significant impact differences between the various urban growth scenarios.;The first chapter investigated the effects of ecoregional boundary choice on gap analysis, a tool used to identify shortfalls in protection of biological resources. A gap analysis for California was conducted using five statewide sets of ecoregional boundaries to identify and compare existing conservation shortfalls in major landcover type representation per ecoregion. Another gap analysis was run for the Central Valley using two temporal baselines. We found that the boundaries of different ecoregional schemes affected both the total area needed to meet the per-ecoregion landcover conservation goals and the spatial location of underprotected landcover types. Choice of temporal baseline also had a significant effect on the establishment of conservation targets.