In Southern California, over 90% of marsh habitat has been destroyed, mostly caused by human impacts. Current research focuses on understanding the dynamics of salt marshes, in an effort to recover and conserve remaining habitat. Our research examines whether salt pannes, bare areas of the marsh, and vegetated areas are alternative stable states in the marsh. The theory of alternative stable states suggests that multiple states, panne or vegetative, exist within one habitat as relatively stable features. We are studying the rate and mechanisms of transition from panne to marsh. As alternative stable states, we hypothesize that the marsh is predominately fully vegetated or bare, but rarely partially vegetated. We also hypothesize that Batis maritima, a salt tolerant plant, facilitates vegetative encroachment on salt pannes. We predicted to find a bimodal distribution of vegetative areas versus bare and an increased presence of Batis if recovery was occurring. To examine the expansion and/or the contraction of the salt pannes, a transect survey was conducted throughout 3 existing salt pannes at Mugu Lagoon, California.
Results/Conclusions
We combined the results from the transect survey conducted with data collected along the same transect in 1995, and 2002. Results show a bimodal distribution of vegetation versus no marsh vegetation, suggesting very little transition between the states. There was an increased presence of Batis maritima, which also suggests it is involved in the transition from panne to vegetation. Current experimentation involves monitoring vegetation growth in response to Batis removal. Ultimately, the experimentation and data collected will offer insight into the recovery and conservation methods for remaining salt marshes.
