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
Integrated analysis shows how the effects of extreme flooding events propagate through fish communities to impact amphibians Integrated analysis shows how the effects of extreme flooding events propagate through fish communities to impact amphibians
Research Highlight: Davis, C. L., Walls, S. C., Barichivich, W. J., Brown, M. E., & Miller, D. A. (2022). Disentangling direct and indirect effects of extreme events on coastal wetland communities. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13874. Catastrophic events such as floods, hurricanes, winter storms, droughts and wildfires increasingly touch our lives either...
Authors
James Grace
From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence
In the long-term absence of disturbance, ecosystems often enter a decline or retrogressive phase which leads to reductions in primary productivity, plant biomass, nutrient cycling and foliar quality. However, the consequences of ecosystem retrogression for higher trophic levels such as herbivores and predators, are less clear. Using a post-fire forested island-chronosequence across which
Authors
Anne Kempel, Eric Allan, Martin M. Gossner, Malte Jochum, James Grace, David A. Wardle
Piñon and juniper tree removal increases available soil water, driving understory response in a sage-steppe ecosystem Piñon and juniper tree removal increases available soil water, driving understory response in a sage-steppe ecosystem
Over the past century, piñon and juniper trees have encroached into sagebrush steppe lands of the interior United States, and managers have for many years removed trees to stimulate the favored understory. While consistent understory response to tree removal in these semiarid lands suggests that trees outcompete other plants for water, no studies have linked increased soil water to...
Authors
James D. McIver, James Grace, Bruce A. Roundy
Direct and indirect influences of macrophyte cover on abundance and growth of juvenile Atlantic salmon Direct and indirect influences of macrophyte cover on abundance and growth of juvenile Atlantic salmon
1. The relationships between macrophytes and the physical and biological characteristics of the environments that aquatic organisms inhabit are complex. Previous studies have shown that the macrophytes, Ranunculus (subgenus Batrachium), which are dominant in lowland chalk streams and widespread across Europe, can enhance juvenile Atlantic salmon abundance and growth to a greater degree...
Authors
Jessica E Marsh, J. Iwan Jones, Rasmus B. Lauridsen, James B. Grace, Pavel Kratina
Migration and transformation of coastal wetlands in response to rising seas Migration and transformation of coastal wetlands in response to rising seas
Coastal wetlands are not only among the world’s most valued ecosystems but also among the most threatened by high greenhouse gas emissions that lead to accelerated sea level rise. There is intense debate regarding the extent to which landward migration of wetlands might compensate for seaward wetland losses. By integrating data from 166 estuaries across the conterminous United States, we...
Authors
Michael Osland, Bogdan Chivoiu, Nicholas Enwright, Karen M. Thorne, Glenn R. Guntenspergen, James Grace, Leah Dale, William Brooks, Nathaniel Herold, John W. Day, Fred H. Sklar, Christopher M. Swarzenski
By
Ecosystems Mission Area, Water Resources Mission Area, Ecosystems Land Change Science Program, Land Management Research Program, Eastern Ecological Science Center, Lower Mississippi-Gulf Water Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center , Gulf of America
Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes
Accelerated sea-level rise and intensifying hurricanes highlight the need to better understand surface elevation change in coastal wetlands. We used the surface elevation table-marker horizon approach to measure surface elevation change in 14 coastal marshes along the northwestern Gulf of Mexico, within five National Wildlife Refuges in Texas (USA). During the 2014–2019 study period, the...
Authors
Jena A. Moon, Laura Feher, Tiffany C. Lane, William Vervaeke, Michael Osland, Douglas M. Head, Bogdan Chivoiu, David R. Stewart, Darren Johnson, James Grace, Kristine L. Metzger, Nicole M. Rankin
General guidance for custom-built structural equation models General guidance for custom-built structural equation models
Structural Equation Modeling (SEM) represents a quantitative methodology for specifying and evaluating causal network hypotheses. The application of SEM typically involves the use of specialized software packages that implement estimation procedures and automate model checking and the output of summary results. There are times when the specification details an investigator wishes to...
Authors
James B. Grace
Instrumental variable methods in structural equation models Instrumental variable methods in structural equation models
Instrumental variable regression (RegIV) provides a means for detecting and correcting parameter bias in causal models. Widely used in economics, recently several papers have highlighted its potential utility for ecological applications. Little attention has thus far been paid to the fact that IV methods can also be implemented within structural equation models (SEMIV). In this paper I...
Authors
James Grace
A protocol for modelling generalised biological responses using latent variables in structural equation models A protocol for modelling generalised biological responses using latent variables in structural equation models
In this paper we consider the problem of how to quantitatively characterize the degree to which a study object exhibits a generalized response. By generalized response, we mean a multivariate response where numerous individual properties change in concerted fashion due to some internal integration. In latent variable structural equation modeling (LVSEM), we would typically approach this...
Authors
James B. Grace, Magdalena Steiner
Biodiversity effects on grape quality depend on variety and management intensity Biodiversity effects on grape quality depend on variety and management intensity
Interactions between plants can be beneficial, detrimental or neutral. In agricultural systems, competition between crop and spontaneous vegetation is a major concern. We evaluated the relative support for three non-exclusive ecological hypotheses about interactions between crop and spontaneous plants based on competition, complementarity or facilitation.The study was conducted in Swiss...
Authors
Magdalena Steiner, James Grace, Sven Bacher
A graphical causal model for resolving species identity effects and biodiversity–ecosystem function correlations: comment A graphical causal model for resolving species identity effects and biodiversity–ecosystem function correlations: comment
In a recent paper, Schoolmaster, Zirbel, and Cronin (SZC) (2020) claim “Formal causal analysis show[s] that biodiversity–ecosystem function (BEF) correlations are non-causal associations.” If this conclusion is accepted as true, it suggests a reconsideration of much of our current understanding of how biodiversity relates to the functioning of ecosystems. On the surface, it is easy to...
Authors
James B. Grace, Michel Loreau, Bernhard Schmid
Hurricane Sandy effects on coastal marsh elevation change Hurricane Sandy effects on coastal marsh elevation change
High-magnitude storm events such as Hurricane Sandy are powerful agents of geomorphic change in coastal marshes, potentially altering their surface elevation trajectories. But how do a storm’s impacts vary across a large region spanning a variety of wetland settings and storm exposures and intensities. We determined the short-term impacts of Hurricane Sandy at 223 surface elevation table...
Authors
Alice G. Yeates, James Grace, Jennifer H. Olker, Glenn R. Guntenspergen, Donald R. Cahoon, Susan C. Adamowicz, Shimon C. Anisfeld, Nels Barrett, Alice Benzecry, Linda K. Blum, Rober T Christian, Joseph Grzyb, Ellen Kracauer Hartig, Kelly Hines Leo, Scott Lerberg, James C. Lynch, Nicole Maher, J Patrick Megonigal, William G. Reay, Drexel Siok, Adam Starke, Vincent Turner, Scott Warren
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
Integrated analysis shows how the effects of extreme flooding events propagate through fish communities to impact amphibians Integrated analysis shows how the effects of extreme flooding events propagate through fish communities to impact amphibians
Research Highlight: Davis, C. L., Walls, S. C., Barichivich, W. J., Brown, M. E., & Miller, D. A. (2022). Disentangling direct and indirect effects of extreme events on coastal wetland communities. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13874. Catastrophic events such as floods, hurricanes, winter storms, droughts and wildfires increasingly touch our lives either...
Authors
James Grace
From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence From bottom-up to top-down control of invertebrate herbivores in a retrogressive chronosequence
In the long-term absence of disturbance, ecosystems often enter a decline or retrogressive phase which leads to reductions in primary productivity, plant biomass, nutrient cycling and foliar quality. However, the consequences of ecosystem retrogression for higher trophic levels such as herbivores and predators, are less clear. Using a post-fire forested island-chronosequence across which
Authors
Anne Kempel, Eric Allan, Martin M. Gossner, Malte Jochum, James Grace, David A. Wardle
Piñon and juniper tree removal increases available soil water, driving understory response in a sage-steppe ecosystem Piñon and juniper tree removal increases available soil water, driving understory response in a sage-steppe ecosystem
Over the past century, piñon and juniper trees have encroached into sagebrush steppe lands of the interior United States, and managers have for many years removed trees to stimulate the favored understory. While consistent understory response to tree removal in these semiarid lands suggests that trees outcompete other plants for water, no studies have linked increased soil water to...
Authors
James D. McIver, James Grace, Bruce A. Roundy
Direct and indirect influences of macrophyte cover on abundance and growth of juvenile Atlantic salmon Direct and indirect influences of macrophyte cover on abundance and growth of juvenile Atlantic salmon
1. The relationships between macrophytes and the physical and biological characteristics of the environments that aquatic organisms inhabit are complex. Previous studies have shown that the macrophytes, Ranunculus (subgenus Batrachium), which are dominant in lowland chalk streams and widespread across Europe, can enhance juvenile Atlantic salmon abundance and growth to a greater degree...
Authors
Jessica E Marsh, J. Iwan Jones, Rasmus B. Lauridsen, James B. Grace, Pavel Kratina
Migration and transformation of coastal wetlands in response to rising seas Migration and transformation of coastal wetlands in response to rising seas
Coastal wetlands are not only among the world’s most valued ecosystems but also among the most threatened by high greenhouse gas emissions that lead to accelerated sea level rise. There is intense debate regarding the extent to which landward migration of wetlands might compensate for seaward wetland losses. By integrating data from 166 estuaries across the conterminous United States, we...
Authors
Michael Osland, Bogdan Chivoiu, Nicholas Enwright, Karen M. Thorne, Glenn R. Guntenspergen, James Grace, Leah Dale, William Brooks, Nathaniel Herold, John W. Day, Fred H. Sklar, Christopher M. Swarzenski
By
Ecosystems Mission Area, Water Resources Mission Area, Ecosystems Land Change Science Program, Land Management Research Program, Eastern Ecological Science Center, Lower Mississippi-Gulf Water Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center , Gulf of America
Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes
Accelerated sea-level rise and intensifying hurricanes highlight the need to better understand surface elevation change in coastal wetlands. We used the surface elevation table-marker horizon approach to measure surface elevation change in 14 coastal marshes along the northwestern Gulf of Mexico, within five National Wildlife Refuges in Texas (USA). During the 2014–2019 study period, the...
Authors
Jena A. Moon, Laura Feher, Tiffany C. Lane, William Vervaeke, Michael Osland, Douglas M. Head, Bogdan Chivoiu, David R. Stewart, Darren Johnson, James Grace, Kristine L. Metzger, Nicole M. Rankin
General guidance for custom-built structural equation models General guidance for custom-built structural equation models
Structural Equation Modeling (SEM) represents a quantitative methodology for specifying and evaluating causal network hypotheses. The application of SEM typically involves the use of specialized software packages that implement estimation procedures and automate model checking and the output of summary results. There are times when the specification details an investigator wishes to...
Authors
James B. Grace
Instrumental variable methods in structural equation models Instrumental variable methods in structural equation models
Instrumental variable regression (RegIV) provides a means for detecting and correcting parameter bias in causal models. Widely used in economics, recently several papers have highlighted its potential utility for ecological applications. Little attention has thus far been paid to the fact that IV methods can also be implemented within structural equation models (SEMIV). In this paper I...
Authors
James Grace
A protocol for modelling generalised biological responses using latent variables in structural equation models A protocol for modelling generalised biological responses using latent variables in structural equation models
In this paper we consider the problem of how to quantitatively characterize the degree to which a study object exhibits a generalized response. By generalized response, we mean a multivariate response where numerous individual properties change in concerted fashion due to some internal integration. In latent variable structural equation modeling (LVSEM), we would typically approach this...
Authors
James B. Grace, Magdalena Steiner
Biodiversity effects on grape quality depend on variety and management intensity Biodiversity effects on grape quality depend on variety and management intensity
Interactions between plants can be beneficial, detrimental or neutral. In agricultural systems, competition between crop and spontaneous vegetation is a major concern. We evaluated the relative support for three non-exclusive ecological hypotheses about interactions between crop and spontaneous plants based on competition, complementarity or facilitation.The study was conducted in Swiss...
Authors
Magdalena Steiner, James Grace, Sven Bacher
A graphical causal model for resolving species identity effects and biodiversity–ecosystem function correlations: comment A graphical causal model for resolving species identity effects and biodiversity–ecosystem function correlations: comment
In a recent paper, Schoolmaster, Zirbel, and Cronin (SZC) (2020) claim “Formal causal analysis show[s] that biodiversity–ecosystem function (BEF) correlations are non-causal associations.” If this conclusion is accepted as true, it suggests a reconsideration of much of our current understanding of how biodiversity relates to the functioning of ecosystems. On the surface, it is easy to...
Authors
James B. Grace, Michel Loreau, Bernhard Schmid
Hurricane Sandy effects on coastal marsh elevation change Hurricane Sandy effects on coastal marsh elevation change
High-magnitude storm events such as Hurricane Sandy are powerful agents of geomorphic change in coastal marshes, potentially altering their surface elevation trajectories. But how do a storm’s impacts vary across a large region spanning a variety of wetland settings and storm exposures and intensities. We determined the short-term impacts of Hurricane Sandy at 223 surface elevation table...
Authors
Alice G. Yeates, James Grace, Jennifer H. Olker, Glenn R. Guntenspergen, Donald R. Cahoon, Susan C. Adamowicz, Shimon C. Anisfeld, Nels Barrett, Alice Benzecry, Linda K. Blum, Rober T Christian, Joseph Grzyb, Ellen Kracauer Hartig, Kelly Hines Leo, Scott Lerberg, James C. Lynch, Nicole Maher, J Patrick Megonigal, William G. Reay, Drexel Siok, Adam Starke, Vincent Turner, Scott Warren