James T Rogala (Former Employee)
Science and Products
Filter Total Items: 26
Thresholds in the response of free-floating plant abundance to variation in hydraulic connectivity, nutrients, and macrophyte abundance in a large floodplain river Thresholds in the response of free-floating plant abundance to variation in hydraulic connectivity, nutrients, and macrophyte abundance in a large floodplain river
Duckweed and other free-floating plants (FFP) can form dense surface mats that affect ecosystem condition and processes, and can impair public use of aquatic resources. FFP obtain their nutrients from the water column, and the formation of dense FFP mats can be a consequence and indicator of river eutrophication. We conducted two complementary surveys of diverse aquatic areas of the...
Authors
Shawn M. Giblin, Jeffrey N. Houser, John F. Sullivan, H.A. Langrehr, James T. Rogala, Benjamin D. Campbell
Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River
River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper...
Authors
Jeffrey N. Houser, Shawn M. Giblin, William F. James, H.A. Langrehr, James T. Rogala, John F. Sullivan, Brian R. Gray
Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River
Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes...
Authors
B. R. Gray, J.R. Rogala, J.N. Houser
Application of Wind Fetch and Wave Models for Habitat Rehabilitation and Enhancement Projects Application of Wind Fetch and Wave Models for Habitat Rehabilitation and Enhancement Projects
Models based upon coastal engineering equations have been developed to quantify wind fetch length and several physical wave characteristics including significant height, length, peak period, maximum orbital velocity, and shear stress. These models were used to quantify differences in proposed island construction designs for three Habitat Rehabilitation and Enhancement Projects (HREPs) in...
Authors
Jason J. Rohweder, James T. Rogala, Barry L. Johnson, Dennis Anderson, Steve Clark, Ferris Chamberlin
Patterns in species richness and assemblage structure of native mussels in the Upper Mississippi River Patterns in species richness and assemblage structure of native mussels in the Upper Mississippi River
1. To evaluate patterns in mussel assemblages in the Upper Mississippi River (UMR), data from systematic surveys of mussels conducted in three large reaches (Navigation Pools 5, 6, and 18) from 2005–2007 were analysed. 2. Nonmetric multi-dimensional scaling analyses and permutation tests indicated that assemblages differed among reaches. The mussel assemblage in Pool 18 was substantially...
Authors
Steven J. Zigler, Teresa J. Newton, Mike Davis, James T. Rogala
Population assessment and potential functional roles of native mussels in the Upper Mississippi River Population assessment and potential functional roles of native mussels in the Upper Mississippi River
1. Despite a heightened global concern for native mussels, fundamental research on mussel ecology in large rivers is lacking. These gaps in knowledge about where mussels occur, and why, are limiting habitat restoration activities. 2. Large-scale systematic surveys for native mussels in three reaches of the Upper Mississippi River documented mussel communities composed of 16–23 species...
Authors
Teresa J. Newton, Steven J. Zigler, James T. Rogala, Brian R. Gray, Mike Davis
Science and Products
Filter Total Items: 26
Thresholds in the response of free-floating plant abundance to variation in hydraulic connectivity, nutrients, and macrophyte abundance in a large floodplain river Thresholds in the response of free-floating plant abundance to variation in hydraulic connectivity, nutrients, and macrophyte abundance in a large floodplain river
Duckweed and other free-floating plants (FFP) can form dense surface mats that affect ecosystem condition and processes, and can impair public use of aquatic resources. FFP obtain their nutrients from the water column, and the formation of dense FFP mats can be a consequence and indicator of river eutrophication. We conducted two complementary surveys of diverse aquatic areas of the...
Authors
Shawn M. Giblin, Jeffrey N. Houser, John F. Sullivan, H.A. Langrehr, James T. Rogala, Benjamin D. Campbell
Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River
River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper...
Authors
Jeffrey N. Houser, Shawn M. Giblin, William F. James, H.A. Langrehr, James T. Rogala, John F. Sullivan, Brian R. Gray
Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River
Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes...
Authors
B. R. Gray, J.R. Rogala, J.N. Houser
Application of Wind Fetch and Wave Models for Habitat Rehabilitation and Enhancement Projects Application of Wind Fetch and Wave Models for Habitat Rehabilitation and Enhancement Projects
Models based upon coastal engineering equations have been developed to quantify wind fetch length and several physical wave characteristics including significant height, length, peak period, maximum orbital velocity, and shear stress. These models were used to quantify differences in proposed island construction designs for three Habitat Rehabilitation and Enhancement Projects (HREPs) in...
Authors
Jason J. Rohweder, James T. Rogala, Barry L. Johnson, Dennis Anderson, Steve Clark, Ferris Chamberlin
Patterns in species richness and assemblage structure of native mussels in the Upper Mississippi River Patterns in species richness and assemblage structure of native mussels in the Upper Mississippi River
1. To evaluate patterns in mussel assemblages in the Upper Mississippi River (UMR), data from systematic surveys of mussels conducted in three large reaches (Navigation Pools 5, 6, and 18) from 2005–2007 were analysed. 2. Nonmetric multi-dimensional scaling analyses and permutation tests indicated that assemblages differed among reaches. The mussel assemblage in Pool 18 was substantially...
Authors
Steven J. Zigler, Teresa J. Newton, Mike Davis, James T. Rogala
Population assessment and potential functional roles of native mussels in the Upper Mississippi River Population assessment and potential functional roles of native mussels in the Upper Mississippi River
1. Despite a heightened global concern for native mussels, fundamental research on mussel ecology in large rivers is lacking. These gaps in knowledge about where mussels occur, and why, are limiting habitat restoration activities. 2. Large-scale systematic surveys for native mussels in three reaches of the Upper Mississippi River documented mussel communities composed of 16–23 species...
Authors
Teresa J. Newton, Steven J. Zigler, James T. Rogala, Brian R. Gray, Mike Davis