Climate change vulnerability assessments for terrestrial and freshwater vertebrates in the Mediterranean Coast Network of national parks

To preserve biodiversity in the 21st century we must understand how changes in the physical environment will differentially alter species fitness. In an effort to aid the National Park Service in protecting the native fauna of the Mediterranean Coast Network, we examined 68 randomly selected species distributed across five taxonomic groups. The species we studied match the proportions that correspond with the ecological communities of the Santa Monica Mountains National Recreation Area, Channel Islands National Park, and Cabrillo National Monument. Using NatureServe’s Climate Change Vulnerability Index — which incorporates modeled future temperature and moisture change and species life history data — we scored each
species’ vulnerability to climate change. Native species were more vulnerable to climate change (t-test; p <.01), with 30% of natives scoring from Moderately Vulnerable (MV) to Extremely Vulnerable (EV), and all non-natives being either Increase Likely (IL) or Presumed Stable (PS). Taxonomically, we found that amphibians and fish are more at risk than birds, reptiles, and mammals, with 100% of the former species scoring between MV and EV. Animals currently listed as federally endangered or threatened are more vulnerable than unlisted species (Mann-Whitney test; p < .001), as are animals on the Channel Islands in comparison to the other two parks. While initially attempting to include plants and invertebrates in our
study, available information about their life histories from web resources, peer-reviewed literature, and expert correspondence was insufficient to complete any assessments. The factors that most affect species’ sensitivity and exposure to climate change in our study are dispersal abilities, sea level rise, and confinement by anthropogenic and natural barriers, which together account for 75% of
vulnerability score variability (multivariate regression; R2= .75; p << .001). These findings
emphasize the importance of habitat corridors, which would allow migrating animals to track
moving climate envelopes, and influences park managers to consider the controversial strategy of assisted migration. Additionally, further research on the life histories of plants and invertebrates, which comprise the bulk of ecosystem biomass, is needed to effectively protect the species of the Mediterranean Coast Network from climate change.