LSU CCR Distinguished Speaker: James Morris
The LSU Center for Coastal Resiliency is thrilled to host Dr. James Morris, Professor of Biological and Marine Sciences at the University of South Carolina.
Thursday, March 30 from 11 AM – Noon in the Dalton J. Woods Auditorium in the Energy, Coast, and Environment Building
The salt marsh as a self-regulating system: it’s a symphony.
James Morris
Professor of Biological and Marine Sciences
University of South Carolina, Columbia, SC, USA
www.biol.sc.edu/~morris
Long-term research at North Inlet estuary, SC resulted in three surprising observations that explain how salt marshes respond to sea-level rise: annual net primary production (ANPP) responds to anomalies in mean sea level; primary production at North Inlet has been rising; and marsh elevation increased after raising ANPP by fertilizing the marsh. This led to the development of a theory of marsh equilibrium: Feedback among sediments, tides, and vegetation establish the productivity and relative elevation of the marsh in equilibrium with sea-level. There is an optimal rate of sea-level rise and a tipping point. Vertical accretion of the marsh surface is dictated by the concentration of suspended sediment, the duration of the flood, and production of new biovolume arising from the turnover and preservation of roots and rhizomes. The vegetation appears to orchestrate the generation of nutrients by stimulating sulfate reducing bacteria. Biogeochemical cycles in North Inlet, SC marshes show a high degree of order and self-determination. The cycles are synchronous with monthly plant growth rates. Phosphate and ammonium concentrations peak during summer months, greatly exceeding concentrations observed in tidal water, are low in the winter, and are synchronous with sulfide concentration. At North Inlet where we have a long time series there is also evidence of an effect of the 18.6-yr lunar nodal cycle. Higher water levels stimulate productivity and raise sulfide and nutrient concentrations. The marsh ecosystem behaves as a well-ordered cybernetic system that compensates for external forcing, including sea-level rise.
Bio: Dr. Morris is the director of the Belle W. Baruch Institute for Marine and Coastal Science and a professor at the University of South Carolina. His research spans the basic and applied aspects of the physiological ecology of plants adapted to wetland habitats and the biogeochemistry and systems ecology of wetlands, primarily salt and freshwater intertidal wetlands.
The Seminar begins at 11:00 am in the Dalton J. Woods Auditorium in the Energy, Coast, and Environment Building. Please share the attached flyer with your colleagues and students.