James Grace, Ph.D. (Former Employee)
Science and Products
Coastal Wetland Vulnerability to Climate Change and Sea-Level Rise: Understanding Ecological Thresholds and Ecosystem Transformations
Eighteen USGS coastal scientists from all four coasts of the conterminous United States are working together to advance the understanding of climate change and sea-level rise impacts to coastal wetlands.
By
California Water Science Center, Chesapeake Bay Activities, Eastern Ecological Science Center, Florence Bascom Geoscience Center, Great Lakes Science Center, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center, Western Ecological Research Center (WERC), Western Geographic Science Center, Wetland and Aquatic Research Center , Woods Hole Coastal and Marine Science Center
Synthesizing Surface Elevation Change Data to Advance Understanding of Sea-level Rise Impacts to Mangrove Forests and Salt Marshes
USGS and NPS partners are working together to analyze and synthesize long-term SET-MH measurements to improve understanding of coastal wetland soil elevation change and ecological responses to sea-level rise.
The Response of Coastal Wetlands to Sea-level Rise: Understanding how Macroscale Drivers Influence Local Processes and Feedbacks
The purpose of this work is to advance our understanding of how coastal wetland responses to sea-level rise (SLR) within the conterminous United States are likely to vary as a function of local, regional, and macroscale drivers, including climate. Based on our interactions with managers and decision makers, as well as our knowledge of the current state of the science, we propose to: (a) conduct a...
The response of coastal wetlands to sea-level rise: Understanding how macroscale drivers influence local processes and feedbacks
The purpose of this work is to advance our understanding of how coastal wetland responses to SLR within the conterminous United States are likely to vary as a function of local, regional, and macroscale drivers, including climate. Based on our interactions with managers and decision makers, as well as our knowledge of the current state of the science, we propose to (a) conduct a national synoptic...
Development of a Multimetric Index for Integrated Assessment of Salt Marsh Condition in the Northeast Coastal and Barrier Network
Salt marsh ecosystems along all US coastlines have been altered, degraded, and destroyed by human activities, including ditching and drainage of the marsh platform, tidal restrictions, discharge of pollutants, and introduction of invasive species. The National Park Service conducts long-term monitoring of salt marsh vegetation and nekton (fish and free-swimming crustaceans) to provide information...
Quantitative Analysis Using Structural Equation Modeling
USGS scientists have been involved for a number of years in the development and use of Structural Equation Modeling (SEM). This methodology represents an approach to statistical modeling that focuses on the study of complex cause-effect hypotheses about the mechanisms operating in systems. SEM is increasingly used in ecological and environmental studies and this site seeks to provide educational...
Improving Our Ability to Forecast Tidal Marsh Response to Sea Level Rise
Our overall objective is to understand what controls the vulnerability of coastal marshes to risks associated with global change drivers and rising sea levels. Fundamental questions pertaining to coastal wetland vulnerability still need to be addressed. What factors explain spatial and geographic variation in tidal wetland vulnerability? How do short term climatic events (storms) influence the...
Structural Equation Modeling in Support of Conservation
Understanding systems sometimes requires approaches that allow for both the discovery of the a system's structure and the estimation of its implications. Structural Equation Modeling - SEM - is one tool scientists use to better understand the complex world in which we live.
Mechanisms of Coastal Marsh Elevation Regulation
Sediment deposition serves an important role in the long-term maintenance of coastal marshes. USGS investigates the mechanisms of coastal marsh elevation regulation to help predict marsh sediment requirements under various sea level rise scenarios.
Filter Total Items: 188
Do non-native plant species affect the shape of productivity-diversity relationships? Do non-native plant species affect the shape of productivity-diversity relationships?
The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though...
Authors
J.M. Drake, E.E. Cleland, M. C. Horner-Devine, E. Fleishman, C. Bowles, M. D. Smith, K. Carney, S. Emery, J. Gramling, D.B. Vandermast, J.B. Grace
Structural equation modeling for observational studies Structural equation modeling for observational studies
Structural equation modeling (SEM) represents a framework for developing and evaluating complex hypotheses about systems. This method of data analysis differs from conventional univariate and multivariate approaches familiar to most biologists in several ways. First, SEMs are multiequational and capable of representing a wide array of complex hypotheses about how system components...
Authors
J.B. Grace
Representing general theoretical concepts in structural equation models: The role of composite variables Representing general theoretical concepts in structural equation models: The role of composite variables
Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we discuss...
Authors
J.B. Grace, K.A. Bollen
Fire and nonnative invasive plants in the central bioregion Fire and nonnative invasive plants in the central bioregion
The Central bioregion is a vast area, stretching from Canada to Mexico and from the eastern forests to the Rocky Mountains, dominated by grasslands and shrublands, but inclusive of riparian and other forests. This bioregion has been impacted by many human induced changes, particularly relating to agricultural practices, over the past 150 years. Also changed are fire regimes, first by...
Authors
James B. Grace, Kristin Zouhar
Long-term dynamics of leafy spurge (Euphorbia esula) and its biocontrol agent, flea beetles in the genus Aphthona Long-term dynamics of leafy spurge (Euphorbia esula) and its biocontrol agent, flea beetles in the genus Aphthona
Three flea beetle species (Aphthona spp.), first introduced into North America in 1988, have come to be regarded as effective biological control organisms for leafy spurge (Euphorbia esula). The black flea beetles (Aphthona lacertosa and A. czwalinae) in particular have been shown to cause reductions in leafy spurge stem counts in the northern Great Plains, while the brown flea beetle (A
Authors
Diane L. Larson, James B. Grace, Jennifer L. Larson
Effects of nutrient loading and extreme rainfall events on coastal tallgrass prairies: Invasion intensity, vegetation responses, and carbon and nitrogen distribution Effects of nutrient loading and extreme rainfall events on coastal tallgrass prairies: Invasion intensity, vegetation responses, and carbon and nitrogen distribution
Soil fertility and precipitation are major factors regulating transitions from grasslands to forests. Biotic regulation may influence the effects of these abiotic drivers. In this study, we examined the effects of extreme rainfall events, anthropogenic nutrient loading and insect herbivory on the ability of Chinese tallow tree (Sapium sebiferum) to invade coastal prairie to determine how...
Authors
E. Siemann, W.E. Rogers, James B. Grace
Short-term disruption of a leafy spurge (Euphorbia esula) biocontrol program following herbicide application Short-term disruption of a leafy spurge (Euphorbia esula) biocontrol program following herbicide application
Integrated pest management (IPM) for invasive plant species is being advocated by researchers and implemented by land managers, but few studies have evaluated the success of IPM programs in natural areas. We assessed the relative effects of components of an IPM program for leafy spurge (Euphorbia esula), an invasive plant, at Theodore Roosevelt National Park, North Dakota. Effects of...
Authors
D.L. Larson, J.B. Grace, P.A. Rabie, P. Andersen
Biogeographic affinity helps explain productivity-richness relationships at regional and local scales Biogeographic affinity helps explain productivity-richness relationships at regional and local scales
The unresolved question of what causes the observed positive relationship between large-scale productivity and species richness has long interested ecologists and evolutionists. Here we examine a potential explanation that we call the biogeographic affinity hypothesis, which proposes that the productivity-richness relationship is a function of species' climatic tolerances that in turn...
Authors
S. Harrison, J.B. Grace
Habitat relationships of birds overwintering in a managed coastal prairie Habitat relationships of birds overwintering in a managed coastal prairie
Grassland birds are considered to be rapidly declining in North America. Management approaches for grassland birds frequently rely on prescribed burning to maintain habitat in suitable condition. We evaluated the relationships among years since burn, vegetation structure, and overwintering grassland bird abundance in coastal prairie. Le Conte's Sparrows (Ammodramus leconteii) were most...
Authors
H.Q. Baldwin, J.B. Grace, W.C. Barrow, F.C. Rohwer
Occurrence of oral deformities in larval anurans Occurrence of oral deformities in larval anurans
We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high...
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
Large-scale causes of variation in the serpentine vegetation of California Large-scale causes of variation in the serpentine vegetation of California
Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this important flora, we analyzed broad...
Authors
J.B. Grace, H.D. Safford, S. Harrison
Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis
Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest...
Authors
D.C. Laughlin, S.R. Abella, W.W. Covington, J.B. Grace
Science and Products
Coastal Wetland Vulnerability to Climate Change and Sea-Level Rise: Understanding Ecological Thresholds and Ecosystem Transformations
Eighteen USGS coastal scientists from all four coasts of the conterminous United States are working together to advance the understanding of climate change and sea-level rise impacts to coastal wetlands.
By
California Water Science Center, Chesapeake Bay Activities, Eastern Ecological Science Center, Florence Bascom Geoscience Center, Great Lakes Science Center, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center, Western Ecological Research Center (WERC), Western Geographic Science Center, Wetland and Aquatic Research Center , Woods Hole Coastal and Marine Science Center
Synthesizing Surface Elevation Change Data to Advance Understanding of Sea-level Rise Impacts to Mangrove Forests and Salt Marshes
USGS and NPS partners are working together to analyze and synthesize long-term SET-MH measurements to improve understanding of coastal wetland soil elevation change and ecological responses to sea-level rise.
The Response of Coastal Wetlands to Sea-level Rise: Understanding how Macroscale Drivers Influence Local Processes and Feedbacks
The purpose of this work is to advance our understanding of how coastal wetland responses to sea-level rise (SLR) within the conterminous United States are likely to vary as a function of local, regional, and macroscale drivers, including climate. Based on our interactions with managers and decision makers, as well as our knowledge of the current state of the science, we propose to: (a) conduct a...
The response of coastal wetlands to sea-level rise: Understanding how macroscale drivers influence local processes and feedbacks
The purpose of this work is to advance our understanding of how coastal wetland responses to SLR within the conterminous United States are likely to vary as a function of local, regional, and macroscale drivers, including climate. Based on our interactions with managers and decision makers, as well as our knowledge of the current state of the science, we propose to (a) conduct a national synoptic...
Development of a Multimetric Index for Integrated Assessment of Salt Marsh Condition in the Northeast Coastal and Barrier Network
Salt marsh ecosystems along all US coastlines have been altered, degraded, and destroyed by human activities, including ditching and drainage of the marsh platform, tidal restrictions, discharge of pollutants, and introduction of invasive species. The National Park Service conducts long-term monitoring of salt marsh vegetation and nekton (fish and free-swimming crustaceans) to provide information...
Quantitative Analysis Using Structural Equation Modeling
USGS scientists have been involved for a number of years in the development and use of Structural Equation Modeling (SEM). This methodology represents an approach to statistical modeling that focuses on the study of complex cause-effect hypotheses about the mechanisms operating in systems. SEM is increasingly used in ecological and environmental studies and this site seeks to provide educational...
Improving Our Ability to Forecast Tidal Marsh Response to Sea Level Rise
Our overall objective is to understand what controls the vulnerability of coastal marshes to risks associated with global change drivers and rising sea levels. Fundamental questions pertaining to coastal wetland vulnerability still need to be addressed. What factors explain spatial and geographic variation in tidal wetland vulnerability? How do short term climatic events (storms) influence the...
Structural Equation Modeling in Support of Conservation
Understanding systems sometimes requires approaches that allow for both the discovery of the a system's structure and the estimation of its implications. Structural Equation Modeling - SEM - is one tool scientists use to better understand the complex world in which we live.
Mechanisms of Coastal Marsh Elevation Regulation
Sediment deposition serves an important role in the long-term maintenance of coastal marshes. USGS investigates the mechanisms of coastal marsh elevation regulation to help predict marsh sediment requirements under various sea level rise scenarios.
Filter Total Items: 188
Do non-native plant species affect the shape of productivity-diversity relationships? Do non-native plant species affect the shape of productivity-diversity relationships?
The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though...
Authors
J.M. Drake, E.E. Cleland, M. C. Horner-Devine, E. Fleishman, C. Bowles, M. D. Smith, K. Carney, S. Emery, J. Gramling, D.B. Vandermast, J.B. Grace
Structural equation modeling for observational studies Structural equation modeling for observational studies
Structural equation modeling (SEM) represents a framework for developing and evaluating complex hypotheses about systems. This method of data analysis differs from conventional univariate and multivariate approaches familiar to most biologists in several ways. First, SEMs are multiequational and capable of representing a wide array of complex hypotheses about how system components...
Authors
J.B. Grace
Representing general theoretical concepts in structural equation models: The role of composite variables Representing general theoretical concepts in structural equation models: The role of composite variables
Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we discuss...
Authors
J.B. Grace, K.A. Bollen
Fire and nonnative invasive plants in the central bioregion Fire and nonnative invasive plants in the central bioregion
The Central bioregion is a vast area, stretching from Canada to Mexico and from the eastern forests to the Rocky Mountains, dominated by grasslands and shrublands, but inclusive of riparian and other forests. This bioregion has been impacted by many human induced changes, particularly relating to agricultural practices, over the past 150 years. Also changed are fire regimes, first by...
Authors
James B. Grace, Kristin Zouhar
Long-term dynamics of leafy spurge (Euphorbia esula) and its biocontrol agent, flea beetles in the genus Aphthona Long-term dynamics of leafy spurge (Euphorbia esula) and its biocontrol agent, flea beetles in the genus Aphthona
Three flea beetle species (Aphthona spp.), first introduced into North America in 1988, have come to be regarded as effective biological control organisms for leafy spurge (Euphorbia esula). The black flea beetles (Aphthona lacertosa and A. czwalinae) in particular have been shown to cause reductions in leafy spurge stem counts in the northern Great Plains, while the brown flea beetle (A
Authors
Diane L. Larson, James B. Grace, Jennifer L. Larson
Effects of nutrient loading and extreme rainfall events on coastal tallgrass prairies: Invasion intensity, vegetation responses, and carbon and nitrogen distribution Effects of nutrient loading and extreme rainfall events on coastal tallgrass prairies: Invasion intensity, vegetation responses, and carbon and nitrogen distribution
Soil fertility and precipitation are major factors regulating transitions from grasslands to forests. Biotic regulation may influence the effects of these abiotic drivers. In this study, we examined the effects of extreme rainfall events, anthropogenic nutrient loading and insect herbivory on the ability of Chinese tallow tree (Sapium sebiferum) to invade coastal prairie to determine how...
Authors
E. Siemann, W.E. Rogers, James B. Grace
Short-term disruption of a leafy spurge (Euphorbia esula) biocontrol program following herbicide application Short-term disruption of a leafy spurge (Euphorbia esula) biocontrol program following herbicide application
Integrated pest management (IPM) for invasive plant species is being advocated by researchers and implemented by land managers, but few studies have evaluated the success of IPM programs in natural areas. We assessed the relative effects of components of an IPM program for leafy spurge (Euphorbia esula), an invasive plant, at Theodore Roosevelt National Park, North Dakota. Effects of...
Authors
D.L. Larson, J.B. Grace, P.A. Rabie, P. Andersen
Biogeographic affinity helps explain productivity-richness relationships at regional and local scales Biogeographic affinity helps explain productivity-richness relationships at regional and local scales
The unresolved question of what causes the observed positive relationship between large-scale productivity and species richness has long interested ecologists and evolutionists. Here we examine a potential explanation that we call the biogeographic affinity hypothesis, which proposes that the productivity-richness relationship is a function of species' climatic tolerances that in turn...
Authors
S. Harrison, J.B. Grace
Habitat relationships of birds overwintering in a managed coastal prairie Habitat relationships of birds overwintering in a managed coastal prairie
Grassland birds are considered to be rapidly declining in North America. Management approaches for grassland birds frequently rely on prescribed burning to maintain habitat in suitable condition. We evaluated the relationships among years since burn, vegetation structure, and overwintering grassland bird abundance in coastal prairie. Le Conte's Sparrows (Ammodramus leconteii) were most...
Authors
H.Q. Baldwin, J.B. Grace, W.C. Barrow, F.C. Rohwer
Occurrence of oral deformities in larval anurans Occurrence of oral deformities in larval anurans
We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high...
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
Large-scale causes of variation in the serpentine vegetation of California Large-scale causes of variation in the serpentine vegetation of California
Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this important flora, we analyzed broad...
Authors
J.B. Grace, H.D. Safford, S. Harrison
Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis
Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest...
Authors
D.C. Laughlin, S.R. Abella, W.W. Covington, J.B. Grace