Colloquium: Dr. Kimberly M. Meitzen
Fri, November 8, 2013 • 4:00 PM - 5:00 PM • CLA 0.128
The Department of Geography and the Environment is pleased to present Dr. Kimberly M. Meitzen for our Fall 2013 Colloquium series. This event is open to the public. For more information call (512)232-1595 or email Madeline Enos at email@example.com.
Flood processes, forest dynamics, and the legacy of historic logging on the Congaree River floodplain, Congaree National Park, South Carolina
Dr. Kimberly M. Meitzen, Assistant Professor, Department of Geography, Texas State University
Southeastern bottomland hardwood ecosystems contain significant habitat heterogeneity and support rich species diversity despite significant human impacts such as logging. We examined forest development dynamics in abandoned meander fluvial landforms on the Congaree River floodplain in Congaree National Park, South Carolina, in order to gain a better understanding of the forest successional responses to hydrogeomorphic gradients and historic logging disturbances. Abandoned meanders are former river bends cut-off from the present channel that overtime fill in with sediment and transition from aquatic to terrestrial conditions. We developed a high-resolution 2D hydrodynamic flood model for simulating complex overland flow processes and quantifying hydrogeomorphic conditions of different abandoned meander features (e.g., flood extent, flood depth, flood frequency, and flood water retention capacity). We incorporated the modeled flow data with structural and compositional forest surveys, additional environmental variables, and historic logging information to compare forest patterns and factors controlling succession in abandoned meander landforms.
Three distinct successional patterns emerged that were linked with disturbance history and hydrogeomorphic conditions. Forest succession in old-growth unlogged environments exhibited a gradual transition from obligate wetland species to facultative species, indicating a natural species turnover with changing hydrogeomorphic conditions of abandon meander infilling. In contrast, recovery patterns in clear-cut forests exhibited complete replacement of the original obligate wetland dominated community to a predominantly facultative community. Selectively logged sites were the most hydric and showed the least amount of successional change, but they lacked recovery of the logged, bald cypress Taxodium distichum component of the forest, which was replaced almost exclusively by Water tupelo Nyssa aquatica. Processes and patterns evidenced in the Congaree River floodplain provide a glimpse of the various controls and successional pathways that produce heterogeneous bottomland forest patterns. The 2D flood model was a valuable tool for modeling complex overland flow processes and has potential for a variety of hydroecological applications. Flood and forest patterns revealed by this study can be used to help guide riparian restoration efforts to reach desired environmental conditions.