Consequences of Climate Change for Native Plants and Conservation

Author(s): Hannah, L.; Shaw, M. R.; Roehrdanz, P.; Ikegami, M.; Soong, O.; Thorne, J. | Abstract: Species ranges are dynamic, and often respond to changes in global climate. Recorded increases of global average temperatures through the twentieth century have already resulted in observed shifts of species ranges within California. Projections of future species distributions under climate change are possible through models that correlate known species occurrences with observed historical climate, then project this correlation onto scenarios of climate change. Previous work in California has focused on modeling changes in the distribution of vegetation and species. This study expands on this work through (1) modeling species at finer spatial scales than previously possible, (2) applying those models in advanced conservation planning tools, and (3) illustrating the intersection of human adaptation and conservation under climate change. Section 1 presents a suite of species distribution models created with climate and water balance data that has been statistically downscaled to finer horizontal resolutions than previous statewide modeling efforts. The models encompass range simulations for over 2,000 native California plant species at scales of 90 meters, 270 meters, 800 meters, 4 kilometers, and 16 kilometers, using three time periods, two global climate models, and two emissions scenarios. Section 2 presents Network Flow Analysis that has been developed as a conservation planning tool to assess landscape connectivity for species to respond to climate change. California is a particularly challenging application for Network Flow Analysis because of its large size and diverse flora. This paper presents methods that have been developed to overcome these challenges and applied as proof-of-concept for use in California. Section 3 presents changing suitability for wine grape cultivation in California using fine-scale (270 meter) climatology. Results from this study show that projected future distributions of climates currently associated with California viticulture may result in cropping changes or other adaptive responses from wine grape growers, with potentially serious implications for land and water conservation.