Consequences of Climate Change for Native Plants and Conservation

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.