Salinity, Flooding, and Urban Impacts to Critical Habitat of the Endangered Red-cockaded Woodpecker
USGS researchers will collect data on salinity, water level, and flooding duration within Big Branch National Wildlife Refuge to improve the understanding of the hydrologic system, and how hydrology drives available red-cockaded woodpecker habitat use and availability across the landscape.
The Science Issue and Relevance: Red-cockaded woodpecker habitat is vulnerable to changes in sea-level through altered hydrology and vegetation. Due to its location in southeast Louisiana, along the northern shore of Lake Pontchartrain, Big Branch National Wildlife Refuge (BBNWR) (Figure 1) will be on the forefront of climate change and relative sea-level rise effects. BBNWR has undergone pine savannah loss and altered hydrology that has been exacerbated by climate change, concurrent sea level rise, and subsidence. Vegetation and hydrologic data provide an essential foundation needed to determine the available habitat for red-cockaded woodpecker use and its quality. BBNWR landscapes and hydrology have been altered through urban development, flood mitigation, and restoration projects. These pine lands provide valuable habitat and other resources for both residential and migratory bird species, of particular interest, is the endangered red-cockaded woodpecker. Refuge-level monitoring of salinity, flooding extent and duration, pine tree structure, encroaching marsh vegetation composition, and elevation is critical for optimizing management for residential and migratory bird use.
This study will help determine how salinity, water level, and flooding duration differ with micro topography within BBNWR, and in turn, how these differences will drive available red-cockaded woodpecker habitat use and availability across the landscape. Our main objective will be to create spatio-temporal distribution models relative to spatial, hydrologic, and environmental gradients which can be used to anticipate future water level and salinity impacts. These data will be used to predict how species respond to hydrological and vegetation changes caused by differing hydrology. This effort focuses on one wildlife refuge that is being impacted by current climate projections; however, the study will provide products transferable to other refuges in coastal lowland pine and wetland habitats.
Methodology for Addressing the Issue: Discrete water-quality and continuous water level and salinity data will be collected in six different red-cockaded woodpecker cluster habitats (Figure 2). Additionally, two continuous water level and salinity stations will be located at two canal access points. Discrete elevation and habitat surveys will use a modified line transect sampling method every 100m over a 500m transect. Additionally, discrete water quality profile data will be collected at the time of vegetation surveys and will include water depth, salinity, water temperature, dissolved oxygen, and pH. Water samples will be collected seasonally to determine suspended sediment and total organic carbon in the water column. Both water and marsh elevations and water quality data will be used to help evaluate changes in salinity and flooding duration and frequency within the pine habitat of BBNWR.
Future Steps: This study will improve the understanding of the hydrologic system, which will inform efforts to improve and restore pine flatwood and savannah habitat. Reforestation of these pine flatwoods is a resource management technique used by BBNWR staff to enhance red-cockaded woodpecker habitat. This study will provide the hydrology and water quality information needed to determine where future reforestation projects should be focused. Though this project focuses on habitat in one national wildlife refuge, it will provide useful data to other coastal refuges with critical red-cockaded woodpecker habitat. Additionally, supplementary data collected may also help address resources of concern within BBNWR, including wintering waterfowl, wood ducks, wading birds, shorebirds, and invasive species.
USGS researchers will collect data on salinity, water level, and flooding duration within Big Branch National Wildlife Refuge to improve the understanding of the hydrologic system, and how hydrology drives available red-cockaded woodpecker habitat use and availability across the landscape.
The Science Issue and Relevance: Red-cockaded woodpecker habitat is vulnerable to changes in sea-level through altered hydrology and vegetation. Due to its location in southeast Louisiana, along the northern shore of Lake Pontchartrain, Big Branch National Wildlife Refuge (BBNWR) (Figure 1) will be on the forefront of climate change and relative sea-level rise effects. BBNWR has undergone pine savannah loss and altered hydrology that has been exacerbated by climate change, concurrent sea level rise, and subsidence. Vegetation and hydrologic data provide an essential foundation needed to determine the available habitat for red-cockaded woodpecker use and its quality. BBNWR landscapes and hydrology have been altered through urban development, flood mitigation, and restoration projects. These pine lands provide valuable habitat and other resources for both residential and migratory bird species, of particular interest, is the endangered red-cockaded woodpecker. Refuge-level monitoring of salinity, flooding extent and duration, pine tree structure, encroaching marsh vegetation composition, and elevation is critical for optimizing management for residential and migratory bird use.
This study will help determine how salinity, water level, and flooding duration differ with micro topography within BBNWR, and in turn, how these differences will drive available red-cockaded woodpecker habitat use and availability across the landscape. Our main objective will be to create spatio-temporal distribution models relative to spatial, hydrologic, and environmental gradients which can be used to anticipate future water level and salinity impacts. These data will be used to predict how species respond to hydrological and vegetation changes caused by differing hydrology. This effort focuses on one wildlife refuge that is being impacted by current climate projections; however, the study will provide products transferable to other refuges in coastal lowland pine and wetland habitats.
Methodology for Addressing the Issue: Discrete water-quality and continuous water level and salinity data will be collected in six different red-cockaded woodpecker cluster habitats (Figure 2). Additionally, two continuous water level and salinity stations will be located at two canal access points. Discrete elevation and habitat surveys will use a modified line transect sampling method every 100m over a 500m transect. Additionally, discrete water quality profile data will be collected at the time of vegetation surveys and will include water depth, salinity, water temperature, dissolved oxygen, and pH. Water samples will be collected seasonally to determine suspended sediment and total organic carbon in the water column. Both water and marsh elevations and water quality data will be used to help evaluate changes in salinity and flooding duration and frequency within the pine habitat of BBNWR.
Future Steps: This study will improve the understanding of the hydrologic system, which will inform efforts to improve and restore pine flatwood and savannah habitat. Reforestation of these pine flatwoods is a resource management technique used by BBNWR staff to enhance red-cockaded woodpecker habitat. This study will provide the hydrology and water quality information needed to determine where future reforestation projects should be focused. Though this project focuses on habitat in one national wildlife refuge, it will provide useful data to other coastal refuges with critical red-cockaded woodpecker habitat. Additionally, supplementary data collected may also help address resources of concern within BBNWR, including wintering waterfowl, wood ducks, wading birds, shorebirds, and invasive species.