Location: Bowdoin / Environmental Studies / Activity / 2014 / Multiple Stable States: Theory and Evidence

Environmental Studies

Multiple Stable States: Theory and Evidence

Story posted October 07, 2014

Event date(s): December 01, 2010 — December 01, 2010

Lunch for students with Steve: Thurs. Oct 9  12:15-1:15, North Dining Room, Moulton Union
Talk: Thursday, Oct 9, 4:00 PM, Druckenmiller Hall, Room 20


One of the most vexing problems in ecology is how distinctly different communities, such as mussel beds and seaweed stands that occur on rocky shores in Maine, can occur in the same ecosystem. These communities often persist for long periods, yet small, temporary shifts in environmental conditions can cause an unexpected tipping of the system and one type of community may be replaced by another. How can alternative communities be both persistent and yet so susceptible? The theory of these systems, known as multiple stable states, is well understood, but whether multiple stable states actually exist in nature has remained a hotly debated subject and, not surprisingly, definitive examples continue to be elusive.​ The past decade has seen resurgent interest in the topic because of large-scale changes in the species composition of many ecosystems around the globe and the extent to which anthropogenic activities and climate change may underlie these sudden shifts. The occurrence of multiple stable states has implications for how we manage ecosystems and our basic understanding of the roles of historical and contemporary processes in determining patterns of organismal distribution and abundance. I will present the results from the past 18 years of an ongoing project investigating whether rockweed stands and mussel beds represent alternative community states in sheltered bays of the Gulf of Maine.

Dr. Steve Dungeon is Associate Professor of Biology, California State University, Northbridge. He received his PhD from the University of Maine in 1992. His research interests focus on the unique biological features of clonal algae and invertebrates, the evolution of life history and morphological traits and how these traits influence the dynamics of the communities in which they live. The temperate rocky intertidal zone is the experimental system used to explore these concepts.