Theses and Dissertations

Advisor

Davis, J.

Committee Member

Morin, Dana

Committee Member

Wang, Guiming

Committee Member

Hagy, Heath

Date of Degree

8-7-2025

Original embargo terms

Immediate Worldwide Access

Document Type

Dissertation - Open Access

Major

Forest Resources

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Forest Resources

Department

Department of Wildlife, Fisheries and Aquaculture

Abstract

Under the assumption that food is limiting to non-breeding waterfowl, Migratory Bird Joint Ventures frequently use daily-ration bioenergetics models to inform wetland conservation objectives. Two essential components of these models include estimates of energy supply (i.e., energetic density) of wetlands used by waterfowl and accurate spatial data layers to determine wetland area. Managed impoundments are important wetland resources for migrating and wintering waterfowl in the South Atlantic Region. However, there is little understanding of the energetic density available to waterfowl in these wetlands regionally, and until recently, a database of digitized impoundments was unavailable for developing a spatial data layer. Therefore, our objectives were to 1) estimate the energetic density in common managed wetland types of the South Atlantic Region and 2) conduct a case study with a managed impoundment spatial layer to investigate the contribution of managed wetlands to overall energetic carrying capacity. These new region-specific estimates of energetic density indicate that current bioenergetics modeling efforts overestimate the forage resources available to waterfowl in managed tidal impoundments and moist-soil wetlands. However, in our case study of 31 hydrological unit code 12 subwatersheds, the current bioenergetics model excluded approximately 73% of impoundments specifically managed for cultivated crops. Consequently, we found that the model underestimated the energetic carrying capacity by nearly 50%. Finally, we worked toward developing a rapid monitoring protocol for semi-permanently flooded wetlands to facilitate more frequent and widespread monitoring of submersed aquatic vegetation (SAV). We developed a procedure where SAV biomass in an impoundment could be precisely estimated in the field (CV < 20%) by obtaining wet weights of ≤ 30 SAV samples. We believe our data will improve future iterations of bioenergetics models for waterfowl habitat conservation planning in the South Atlantic Region. As wetlands of the region face threats from sea-level rise and tropical storm damage, maintaining the population-based habitat objectives under the North American Waterfowl Management Plan may hinge on our ability to identify and mitigate the potential loss or degradation of waterfowl foraging habitat.

Sponsorship (Optional)

U.S. Fish and Wildlife Service, U.S. Geological Survey, Nemours Wildlife Foundation, Mississippi State University James C. Kennedy Endowed Chair in Waterfowl and Wetlands Conservation

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