Project Title

Predicting and Mitigating Potential Climate Change Effects on a Regionally Dominant Ecotonal Desert Shrub

Abstract

Blackbrush (Coleoogyne ramosissima) is a regionally dominant shrub species important in the transition zone between North American warm and cold deserts, occupying millions of hectares on National Park Service, Bureau of Land Management and National Forest System lands. Blackbrush is an ideal model species for examining climate change response because it occupies a relatively narrow band between two major climatic zones and is representative of a large group of slow-growing desert shrub species. We have extensive data sets on the demographic response of blackbrush to short-term climatic fluctuation, disturbance, and vegetation change across its range, and have established that it is at serious risk, not only from potential climate change, but also from more immediate effects of annual brome invasion and resulting increases in wildfire. Current and future studies incorporate these data as a basis for addressing the nature of adaptation of blackbrush populations to climate by examining the role of among- and within- population genetic (ecotypic) variation vs. plastic acclimatization response. We are using morphometric, ecophysiological and molecular genetic tools to characterize plants in wild populations as well as in a series of common gardens in contrasting environments. Our goal is to identify and quantify genetic variation that will likely affect fitness across the climatic transition gradient. We also plan to build on our existing field data sets to create models for predicting climate change outcomes for blackbrush. The results of these efforts will be integrated with bioclimatological models that predict future distributions to determine the probability that blackbrush populations will persist in situ or successfully migrate in response to climate change. Our genecological studies enable us to incorporate the spatial distribution of adaptively significant genetic variation into these models. Lastly, we will use our models to design and implement ‘assisted’ colonization experiments in the predicted future range of blackbrush. We anticipate that research will lead to much-needed science-based restoration technology and seed transfer guidelines and a predictive approach to climate change effects that can potentially be applied to many other desert shrub species.

Selected Publications

Rosemary Pendleton, USDA FS

Flowering blackbrush in a natural community near Browse, UT

GSD Principal Investigators

Cooperators and Sponsors

Todd Esque, USGS – Western Ecological Research Center, Las Vegas, NV