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
Compact development and VMT: environmental determinism, self-selection, or some of both? Compact development and VMT: environmental determinism, self-selection, or some of both?
There is a long-running debate in the planning literature about the effects of the built environment on travel behavior and the degree to which apparent effects are due to the tendency of households to self-select into neighborhoods that reinforce their travel preferences. Those who want to walk will choose walkable neighborhoods, and those who want to use transit will choose transit...
Authors
Reid Ewing, Shima Hamidi, James B. Grace
From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology
In this perspectives paper we highlight a heretofore underused statistical method in soil ecological research, structural equation modeling (SEM). SEM is commonly used in the general ecological literature to develop causal understanding from observational data, but has been more slowly adopted by soil ecologists. We provide some basic information on the many advantages and possibilities...
Authors
Nico Eisenhauer, Jeff R Powell, James B. Grace, Matthew A. Bowker
Do shrubs reduce the adverse effects of grazing on soil properties? Do shrubs reduce the adverse effects of grazing on soil properties?
Increases in the density of woody plants are a global phenomenon in drylands, and large aggregations of shrubs, in particular, are regarded as being indicative of dysfunctional ecosystems. There is increasing evidence that overgrazing by livestock reduces ecosystem functions in shrublands, but that shrubs may buffer the negative effects of increasing grazing. We examined changes in water
Authors
David J. Eldridge, Genevieve Beecham, James B. Grace
Structural equation modeling: Building and evaluating causal models Structural equation modeling: Building and evaluating causal models
Scientists frequently wish to study hypotheses about causal relationships, rather than just statistical associations. This chapter addresses the question of how scientists might approach this ambitious task. Here we describe structural equation modeling (SEM), a general modeling framework for the study of causal hypotheses. Our goals are to (a) concisely describe the methodology, (b)...
Authors
James B. Grace, Samuel M. Scheiner, Donald R. Schoolmaster
Long-term effects of seeding after wildfire on vegetation in Great Basin shrubland ecosystems Long-term effects of seeding after wildfire on vegetation in Great Basin shrubland ecosystems
1. Invasive annual grasses alter fire regimes in shrubland ecosystems of the western USA, threatening ecosystem function and fragmenting habitats necessary for shrub-obligate species such as greater sage-grouse. Post-fire stabilization and rehabilitation treatments have been administered to stabilize soils, reduce invasive species spread and restore or establish sustainable ecosystems in...
Authors
Kevin C. Knutson, David A. Pyke, Troy A. Wirth, Robert S. Arkle, David S. Pilliod, Matthew L. Brooks, Jeanne C. Chambers, James B. Grace
A synopsis of short-term response to alternative restoration treatments in sagebrush-steppe: the SageSTEP project A synopsis of short-term response to alternative restoration treatments in sagebrush-steppe: the SageSTEP project
The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is an integrated long-term study that evaluates ecological effects of alternative treatments designed to reduce woody fuels and to stimulate the herbaceous understory of sagebrush steppe communities of the Intermountain West. This synopsis summarizes results through 3 yr posttreatment. Woody vegetation reduction by prescribed...
Authors
James McIver, Mark Brunson, Steve Bunting, Jeanne Chambers, Paul Doescher, James Grace, April Hulet, Dale Johnson, Steven T. Knick, Richard Miller, Mike Pellant, Fred Pierson, David Pyke, Benjamin Rau, Kim Rollins, Bruce Roundy, Eugene Schupp, Robin Tausch, Jason Williams
Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments
In sagebrush ecosystems invasion of annual exotics and expansion of piñon (Pinus monophylla Torr. and Frem.) and juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes and resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience to disturbance and enhance resistance to invasive species by reducing woody...
Authors
Jeanne C. Chambers, Richard F. Miller, David I. Board, David A. Pyke, Bruce A. Roundy, James B. Grace, Eugene W. Schupp, Robin J. Tausch
Causal networks clarify productivity-richness interrelations, bivariate plots do not Causal networks clarify productivity-richness interrelations, bivariate plots do not
Perhaps no other pair of variables in ecology has generated as much discussion as species richness and ecosystem productivity, as illustrated by the reactions by Pierce (2013) and others to Adler et al.'s (2011) report that empirical patterns are weak and inconsistent. Adler et al. (2011) argued we need to move beyond a focus on simplistic bivariate relationships and test mechanistic
Authors
James B. Grace, Peter B. Adler, W. Stanley Harpole, Elizabeth T. Borer, Eric W. Seabloom
Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data
The Natural Resource Challenge (National Park Service 1999) was a call to action. It constituted a mandate for monitoring based on the twin premises that (1) natural resources in national parks require active management and stewardship if we are to protect them from gradual degradation, and (2) we cannot protect what we do not understand. The intent of the challenge was embodied in its
Authors
James B. Grace, Donald R. Schoolmaster, E. William Schweiger, Brian R. Mitchell, Kathryn Miller, Glenn R. Guntenspergen
Combined effects of compact cevelopment, transportation investments, and road user pricing on vehicle miles traveled in urbanized areas Combined effects of compact cevelopment, transportation investments, and road user pricing on vehicle miles traveled in urbanized areas
Vehicle miles traveled (VMT) is the primary determinant of traffic congestion, vehicle crashes, greenhouse gas emissions, and other effects of transportation. Two previous studies have sought to explain VMT levels in urbanized areas. This study updates and expands on previous work with more recent data, additional metrics, and structural equation modeling (SEM) to explain VMT levels in...
Authors
Reid Ewing, Shima Hamidi, Frank Gallivan, Arthur C. Nelson, James B. Grace
Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin
A recurrent challenge in the conservation of wide-ranging, imperiled species is understanding which habitats to protect and whether we are capable of restoring degraded landscapes. For Greater Sage-grouse (Centrocercus urophasianus), a species of conservation concern in the western United States, we approached this problem by developing multi-scale empirical models of occupancy in 211...
Authors
Robert S. Arkle, David S. Pilliod, Steven E. Hanser, Matthew L. Brooks, Jeanne C. Chambers, James B. Grace, Kevin C. Knutson, David A. Pyke, Justin L. Welty
Getting the message across: using ecological integrity to communicate with resource managers Getting the message across: using ecological integrity to communicate with resource managers
This chapter describes and illustrates how concepts of ecological integrity, thresholds, and reference conditions can be integrated into a research and monitoring framework for natural resource management. Ecological integrity has been defined as a measure of the composition, structure, and function of an ecosystem in relation to the system’s natural or historical range of variation, as...
Authors
Brian R. Mitchell, Geraldine L. Tierney, E. William Schweiger, Kathryn M. Miller, Don Faber-Langendoen, James 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
Compact development and VMT: environmental determinism, self-selection, or some of both? Compact development and VMT: environmental determinism, self-selection, or some of both?
There is a long-running debate in the planning literature about the effects of the built environment on travel behavior and the degree to which apparent effects are due to the tendency of households to self-select into neighborhoods that reinforce their travel preferences. Those who want to walk will choose walkable neighborhoods, and those who want to use transit will choose transit...
Authors
Reid Ewing, Shima Hamidi, James B. Grace
From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology
In this perspectives paper we highlight a heretofore underused statistical method in soil ecological research, structural equation modeling (SEM). SEM is commonly used in the general ecological literature to develop causal understanding from observational data, but has been more slowly adopted by soil ecologists. We provide some basic information on the many advantages and possibilities...
Authors
Nico Eisenhauer, Jeff R Powell, James B. Grace, Matthew A. Bowker
Do shrubs reduce the adverse effects of grazing on soil properties? Do shrubs reduce the adverse effects of grazing on soil properties?
Increases in the density of woody plants are a global phenomenon in drylands, and large aggregations of shrubs, in particular, are regarded as being indicative of dysfunctional ecosystems. There is increasing evidence that overgrazing by livestock reduces ecosystem functions in shrublands, but that shrubs may buffer the negative effects of increasing grazing. We examined changes in water
Authors
David J. Eldridge, Genevieve Beecham, James B. Grace
Structural equation modeling: Building and evaluating causal models Structural equation modeling: Building and evaluating causal models
Scientists frequently wish to study hypotheses about causal relationships, rather than just statistical associations. This chapter addresses the question of how scientists might approach this ambitious task. Here we describe structural equation modeling (SEM), a general modeling framework for the study of causal hypotheses. Our goals are to (a) concisely describe the methodology, (b)...
Authors
James B. Grace, Samuel M. Scheiner, Donald R. Schoolmaster
Long-term effects of seeding after wildfire on vegetation in Great Basin shrubland ecosystems Long-term effects of seeding after wildfire on vegetation in Great Basin shrubland ecosystems
1. Invasive annual grasses alter fire regimes in shrubland ecosystems of the western USA, threatening ecosystem function and fragmenting habitats necessary for shrub-obligate species such as greater sage-grouse. Post-fire stabilization and rehabilitation treatments have been administered to stabilize soils, reduce invasive species spread and restore or establish sustainable ecosystems in...
Authors
Kevin C. Knutson, David A. Pyke, Troy A. Wirth, Robert S. Arkle, David S. Pilliod, Matthew L. Brooks, Jeanne C. Chambers, James B. Grace
A synopsis of short-term response to alternative restoration treatments in sagebrush-steppe: the SageSTEP project A synopsis of short-term response to alternative restoration treatments in sagebrush-steppe: the SageSTEP project
The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is an integrated long-term study that evaluates ecological effects of alternative treatments designed to reduce woody fuels and to stimulate the herbaceous understory of sagebrush steppe communities of the Intermountain West. This synopsis summarizes results through 3 yr posttreatment. Woody vegetation reduction by prescribed...
Authors
James McIver, Mark Brunson, Steve Bunting, Jeanne Chambers, Paul Doescher, James Grace, April Hulet, Dale Johnson, Steven T. Knick, Richard Miller, Mike Pellant, Fred Pierson, David Pyke, Benjamin Rau, Kim Rollins, Bruce Roundy, Eugene Schupp, Robin Tausch, Jason Williams
Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments
In sagebrush ecosystems invasion of annual exotics and expansion of piñon (Pinus monophylla Torr. and Frem.) and juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes and resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience to disturbance and enhance resistance to invasive species by reducing woody...
Authors
Jeanne C. Chambers, Richard F. Miller, David I. Board, David A. Pyke, Bruce A. Roundy, James B. Grace, Eugene W. Schupp, Robin J. Tausch
Causal networks clarify productivity-richness interrelations, bivariate plots do not Causal networks clarify productivity-richness interrelations, bivariate plots do not
Perhaps no other pair of variables in ecology has generated as much discussion as species richness and ecosystem productivity, as illustrated by the reactions by Pierce (2013) and others to Adler et al.'s (2011) report that empirical patterns are weak and inconsistent. Adler et al. (2011) argued we need to move beyond a focus on simplistic bivariate relationships and test mechanistic
Authors
James B. Grace, Peter B. Adler, W. Stanley Harpole, Elizabeth T. Borer, Eric W. Seabloom
Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data Connecting the dots: a collaborative USGS-NPS effort to expand the utility of monitoring data
The Natural Resource Challenge (National Park Service 1999) was a call to action. It constituted a mandate for monitoring based on the twin premises that (1) natural resources in national parks require active management and stewardship if we are to protect them from gradual degradation, and (2) we cannot protect what we do not understand. The intent of the challenge was embodied in its
Authors
James B. Grace, Donald R. Schoolmaster, E. William Schweiger, Brian R. Mitchell, Kathryn Miller, Glenn R. Guntenspergen
Combined effects of compact cevelopment, transportation investments, and road user pricing on vehicle miles traveled in urbanized areas Combined effects of compact cevelopment, transportation investments, and road user pricing on vehicle miles traveled in urbanized areas
Vehicle miles traveled (VMT) is the primary determinant of traffic congestion, vehicle crashes, greenhouse gas emissions, and other effects of transportation. Two previous studies have sought to explain VMT levels in urbanized areas. This study updates and expands on previous work with more recent data, additional metrics, and structural equation modeling (SEM) to explain VMT levels in...
Authors
Reid Ewing, Shima Hamidi, Frank Gallivan, Arthur C. Nelson, James B. Grace
Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin
A recurrent challenge in the conservation of wide-ranging, imperiled species is understanding which habitats to protect and whether we are capable of restoring degraded landscapes. For Greater Sage-grouse (Centrocercus urophasianus), a species of conservation concern in the western United States, we approached this problem by developing multi-scale empirical models of occupancy in 211...
Authors
Robert S. Arkle, David S. Pilliod, Steven E. Hanser, Matthew L. Brooks, Jeanne C. Chambers, James B. Grace, Kevin C. Knutson, David A. Pyke, Justin L. Welty
Getting the message across: using ecological integrity to communicate with resource managers Getting the message across: using ecological integrity to communicate with resource managers
This chapter describes and illustrates how concepts of ecological integrity, thresholds, and reference conditions can be integrated into a research and monitoring framework for natural resource management. Ecological integrity has been defined as a measure of the composition, structure, and function of an ecosystem in relation to the system’s natural or historical range of variation, as...
Authors
Brian R. Mitchell, Geraldine L. Tierney, E. William Schweiger, Kathryn M. Miller, Don Faber-Langendoen, James B. Grace