Christopher A. Gabler

Ecology and Evolutionary Biology
Rice University

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[Last updated in early 2006; big revisions on the way in May 2008]

My work in community ecology has focused on restoration biology and invasive species management in freshwater wetlands and bottomland hardwood forests of Texas and Louisiana. An underlying goal of all my research is to unite ecological theory with modern restoration and management methods. Though botanical in scope thus far, future research will delve into the realm of zoology to investigate effects and management of invasive animals and the use of indicator animal species to assess ecosystem quality or function.

I have two years of undergraduate and two years of graduate research experience. I began my graduate studies at Tulane with Jeff Chambers, but was displaced from New Orleans by Hurricane Katrina at the beginning of my second year. Ischel and I evacuated with our pack of dogs and coterie of rodents before the storm hit and we carved out a niche for ourselves in Houston, where I am native. I spent Fall 2006 as a visiting grad student and research assistant at Rice University and officially transferred to Rice that spring. While my coursework carried over, most of my research did not. Fortunately, I was able to get several new projects off the ground quickly thanks to the support of my advisor, Evan Siemann, and the resources available in his lab.

To date, my particular research projects have spanned four distinct ecosystems:

1. Mississippi River Delta National Wildlife Refuge, Louisiana, USA
   • Long-term wetland biomass dynamics and accretion (growth) modeling in the Delta NWR
     • 2003-present
     • Collaborators include David White of Loyola University New Orleans (my undergraduate advisor).
     • I have utilized biomass sampling and GIS analysis of aerial photographs (beginning in 1978) to quantify the accretion and production of a hydrologically restored river-dominated wetland marsh system in the Brants Pass Splay area of the refuge since its nascence 27 years ago (caused by a natural levee breech).
     • The current primary goal is to illustrate significant correlations between wetland accretion and the abiotic factors that drive land building, such as river flow, sedimentation and erosion. However, I ultimately intend to use this data to create a model capable of predicting the change in wetland landmass given certain conditions, or the conditions necessary to sustain existing wetlands.
     • The first year's work served at the basis of my undergraduate honors thesis.
     • In the summer of 2005 I presented our most recent findings at the annual conference of the Society of Wetland Scientists in Charleston, SC.
   
   
2. Pearl River Wildlife Management Area, Louisiana, USA
   • Monitoring long-term bottomland hardwood forest productivity
   • Investigating the viability of remote sensing as a carbon-sink management tool for Gulf Coast forests
     • 2004-2005
     • Collaborators include Jeff Chambers (PI), Mark Tobler, and Elise Chapman of Tulane University, and David White of Loyola University.
     • My work was on canopy productivity dynamics and measuring leaf nitrogen content. We hoped to demonstrate both a strong correlation between annual productivity and canopy N content, and that canopy N could be accurately measured at the landscape scale via remote sensing, which would allow investigators to identify specific regions of importance in mitigating increases in atmospheric carbon.
     • This project was interrupted by Hurricane Katrina and the subsequent temporary closing of Tulane and Loyola and the subsequent dispersal of the researchers involved, but is expected to resume in 2006.
   
   
3. Big Thicket National Preserve, Texas, USA
   • Direct and indirect hurricane impacts on Sapium-invaded vs. Sapium-managed bottomland hardwood forests
     • 2005-present
     • Collaborators include Evan Siemann (PI) of Rice University.
     • My role thus far has been cataloguing
       • direct hurricane damage to previously surveyed trees and saplings in sixteen existing 16-ha plots (8 managed, 8 control) and
       • fallen canopy trees along transects connecting the existing survey sites within plot interiors
     • I will also utilize high-resolution aerial photographs and GIS software to quantify the size and relative frequency of light gaps over the full extent of these plots.
     • Surveys will continue regularly to account for indirect tree mortality stemming from Hurricane Rita.
     • Statistical tests will show whether there is a significant difference in hurricane impacts between control sites and the five-year-old Sapium kill sites.
     • The full extent of my role in this project is currently uncertain.
   
   
4. Gulf Coast Wetlands, USA
   • Evaluating multiple restoration techniques and estimating the impact of invasive Sapium sebiferum on recruitment, competitive exclusion, and successional trajectories in wetland marshes of the Gulf Coast
     • 2004-present
     • This research is anticipated to be the core of my dissertation, but is currently in an organizational phase where logistics such as land use permits are still being worked out and funding is still being sought.
     • The project as planned will include three major parts.
       • The first would include extensive surveys of plant community structure and composition in pristine wetlands and restored wetlands of three different management regimes in order to delineate any significant divergences in the biodiversity, successional trajectory or invasive prevalence of restored wetlands from that of the pristine condition.
       • The second part would include the establishment of eight treatments within degraded marshland using a full factorial design including the common management practices of native seeding and adult transplants and invasive removal. These treatment plots will be subjected to the same community surveys as in part one in order to compare the effectiveness of different combinations of management practices to one another and to the results from part one.
         • In parts one and two, a major focus will be placed on non-native and invasive species.
       • The third part will involve extensive greenhouse work in order to isolate the effects of soil type, salinity, water regime, adult competition and competitive germination on Sapium, and the effects of adult competition and competitive germination on either five or six native wetland species.
     • The intention of this project is to develop a relatively comprehensive study on wetland restoration, how invasive species may affect restorative efforts, and how to most effectively manage invasive threats.

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