Linking UC resources to better understand future climatic change
by Erin C. Riordan
Over the next century, climate change is expected to significantly impact California’s environment, threatening biodiversity, ecosystem services, and human systems across the state. Protected areas, such as those maintained by the University of California Natural Reserve System (NRS), are essential for conserving the state’s rich biodiversity, but face growing challenges under mounting environmental change. The magnitude of projected climate change this century could dramatically impact the conservation value of protected areas, including their ability to provide suitable habitat supporting the key species and ecosystems they are intended to protect.
The NRS is the largest universityoperated reserve system in the world with 39 reserves encompassing over 750,000 acres and spanning 12 major ecoregions in California. The system’s future role in protecting California’s biodiversity and natural resources, however, is uncertain in the face of global climate change. In order to assess the future effectiveness of the NRS, I am working at UC Berkeley as a postdoctoral researcher with professors Phil Rundel (UCLA) and David Ackerly (UC Berkeley) in collaboration with Dr. Peggy Fiedler (NRS director) on a project that will model the potential impacts of climate change on key California plant taxa in NRS reserves.
Using information on species locations from herbarium records of the Consortium of California Herbaria (CCH) and species lists from the California Native Plant Society (CNPS), I am modeling future climate-driven changes in suitable habitat for rare plant taxa across the NRS reserve network. The Consortium, which compiles digitized herbarium records from nearly 30 participating herbaria and institutions throughout California, provides a wealth of information on plant specimens in the state and was an essential resource for mining geographic data for rare plant species models.
Our project will create a number of useful maps and products for both research and management communities. Maps of current suitable habitat can be used as exploratory tools to guide surveys for rare taxa that may not currently be listed in reserves but could occur within reserve boundaries. Future habitat suitability maps will identify priority taxa within reserves that may be at high risk for climate-driven habitat losses. They can also identify taxa and reserves that may be relatively insensitive to projected climate change. Stable reserves could serve as important refugia that may buffer climate change impacts for a number of species.
For example, desert sage (Salvia eremostachya) in the Lamiaceae is a California Rare Plant Rank (CRPR) List 4 species of limited distribution in California that occurs on the NRS’s Boyd Deep Canyon Desert Research Center in Riverside County. Its status corresponds to a "watch list" from CNPS that contains plant taxa that cannot be classified as rare but are sufficiently uncommon to warrant monitoring. Desert sage is one of the species that could be at risk of climate-driven habitat loss by the end of this century, both from within the Boyd Deep Canyon Desert Research Center as well as statewide.
This project provides a comprehensive, system-wide analysis of potential climate change impacts on critical California plant taxa that will complement a variety of monitoring and research studies already in progress at individual reserves. It marks a critical step in developing system-wide adaptive management strategies to help ensure the future role of the NRS in preserving California’s biodiversity.