Effects of climate change on a restored southern California salt marsh community

Dr Christine Whitcraft¹, Anastasia Shippey¹

¹Csu Long Beach, Long Beach, United States

Salt marshes provide many critical ecosystem functions, several of which are threatened by human activities such as urban development and climate change. One method for combatting this loss and degradation is restoration. Under current climate conditions, salt marsh communities are well-understood, and restoration techniques are known to be effective; yet the success of these restorations is unknown under altered climate regimes. Southern California is known to have a Mediterranean climate characterized rain in the winter and dry conditions in the summer. Climate change projections for this region include increased frequency of severe storms, longer periods of drought, and increases in temperature. In a randomized block design experiment, we evaluated how altered precipitation (increased and decreased) and increased temperature affected a restored high marsh community in southern California. Overall, total plant cover was reduced in treatments with decreased precipitation, and the frequency of non-native species increased in these treatments. These same treatments also had an increase in microalgal abundance as measured via chlorophyll a, potentially due to an increase in light availability. The invertebrate community was slower to respond to changes in climate. However, treatments combining increases in temperature and precipitation had an increase in overall abundance as well as an increase in diversity of invertebrates as compared to other treatments and controls. Our final results can provide managers of future restorations information to assist in design and budgets by understanding the success of salt marsh communities under different climate change scenarios, including synergistic impacts of multiple stressors.

Biography:

Dr. Christine Whitcraft is an associate professor in Biological Sciences and director of the Environmental Science and Policy program at California State University Long Beach. Her research focuses on anthropogenic impacts to coastal wetlands. Specifically, she focuses on the impacts of reduced connectivity through development, spread of invasive species, and alterations to hydrologic regimes on food webs. In addition, her research evaluates effective methods by which to evaluate and restore degraded marsh ecoystems