Coastal Forests and Climate Change

This is a collaborative project with Dr. Julie Denslow (U.S.D.A. Forest Service, Hilo, HI).  We initiated this study to investigate effects of relative sea level rise on coastal forest dynamics in the Mississippi River Deltaic Plain.   In 1998, we established a 5 hectare plot spanning the natural levee to the backswamp of Bayou des Familles, a former distributary of the Mississippi River.  The plot is located in the Barataria Preserve Unit of Jean Lafitte National Historical Park and Preserve.  All trees > 2.5 cm DBH were tagged, identified, and measured.  These trees and recruits were surveyed in 2000, 2002,  and again in 2006 and 2008 following Hurricanes Katrina and Rita.  Prior to the hurricanes, we found high mortality and low regeneration of dominant canopy species.  The hurricanes have dramatically opened up the canopy, which may promote regeneration of shade-intolerant species in particular.  Alternatively, we may find that the storms are contributing to a speedier demise for some species.  This ongoing, long-term study of forest dynamics in one of the most rapidly changing areas in the world can be used as a model system to study ecological response to rapid environmental change.

Ecological Assessment of High Quality UMRS Floodplain Forests

This is a collaborative project with Drs Lyle Guyon (National Great Rivers and John Chick (Illinois Natural History Survey).  Floodplain forests associated with the Upper Mississippi River System (UMRS) have been significantly reduced in acreage from pre-settlement levels due to timber harvesting, conversion to agricultural cropland, and other land use changes. Currently, remaining floodplain forests are significantly affected by the altered hydrological regimes associated with river impoundment. These historical and present day disturbances have contributed to long-term changes in the composition and structure of UMRS floodplain forests, as well as negatively affecting their overall health and general condition. A loss of tree species diversity, most importantly the hard mast component (e.g., oaks), has been identified as a prominent management concern in this ecosystem. A lack of successful regeneration has also been documented in many areas, which could result in further losses in forest habitat over time. This loss of forest cover and tree species diversity has been projected to continue into the future unless active management of floodplain forests can reverse this trend. The objective of this project is to assess the physical and biological characteristics of remaining high quality floodplain forest in the Upper Mississippi River System (UMRS). This assessment will be an integral step towards establishing a suite of baseline ecological reference information that will in turn facilitate future floodplain forest restoration efforts in the UMRS.

updated April 15, 2009/llb