Evolutionary dimensions of ecosystem responses to climate change
Michael J. Blum
Director, The ByWater Institute
Eugenie Schwartz Professor of River & Coastal Studies and Associate Professor, Dept of Ecology & Evolutionary Biology, Tulane University
ABSTRACT: There is good reason to think that evolution is an essential aspect of how ecosystems function- not only can the expression of heritable traits of a single species influence ecosystem processes, but evolution can occur on ecological timescales. Yet current projections of ecosystem responses to climate change do not account for evolution. Should they? The influence of rising atmospheric CO2 and corollaries of climate change (e.g., rising sea levels) on coastal marsh plants presents an especially compelling framework for considering whether forecasts should account for evolution. Even small evolutionary changes in the capacity of plants to accommodate rising CO2 and other climate-related stressors can have pronounced aggregate impacts on marsh ecosystem structure and function. I will discuss how, through unprecedented use of persistent seed banks to ‘resurrect’ living organisms from the past, ongoing efforts are reconstructing the tempo and magnitude of evolutionary responses of a foundational marsh sedge (Schoenoplectus americanus) to climate stressors since the Industrial Revolution. I will overview how paleoecological, experimental and computational approaches are being taken to disentangle the effects of heritable responses from the effects of phenotypic plasticity and environmental variation on vital ecosystem processes (e.g., productivity, accretion) that can determine the fate of coastal marshes. Finally I will discuss the value of integrating data through a Bayesian assimilation framework to estimate the aggregate importance of evolution and to assess how further data collection and model improvements can strengthen predictive forecasting of marsh ecosystem persistence under future climate scenarios.
Michael Blum is the Eugenie Schwartz Professor of River & Coastal Studies and Associate Professor of Ecology and Evolutionary Biology at Tulane University. Mike earned a B.A. in Integrative Biology at the University of California, Berkeley and a Ph.D. from Duke University. He then completed a 4-year postdoctoral fellowship in the Office of Research and Development of the U.S. Environmental Protection Agency before joining the Tulane faculty in 2007. Mike's expertise is in molecular ecology, the ecology of riverine and coastal ecosystems, and the socio-ecology of urban deltas. He is well known for his work on the development of genetic methods for assessing the condition of aquatic environments, responses of coastal marsh ecosystems to global environmental change, and coupled natural-human ecosystem dynamics. While serving as the Arnold Early Career Professor in Earth and Ecological Science, Mike worked closely with academic, government and industry partners to advance coastal remediation and recovery following the Deepwater Horizon oil spill. Mike also has led National Science Foundation-funded projects to develop New Orleans as an urban long-term research area to study outcomes of catastrophic disasters as well as socioeconomic and human health drivers of biological diversity. As the Director of the Tulane-Xavier Center for Bioenvironmental Research, and now the founding Director of the Tulane ByWater Institute, Mike has been leading cross-cutting initiatives on energy, environment and resilience to enrich university commitments to public service. His work has been featured by media outlets including National Geographic, The Atlantic, The New York Times, CNN, Fox News, NPR, BBC, and Comedy Central.