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
Predicting performance for ecological restoration: A case study using Spartina altemiflora Predicting performance for ecological restoration: A case study using Spartina altemiflora
The success of population-based ecological restoration relies on the growth and reproductive performance of selected donor materials, whether consisting of whole plants or seed. Accurately predicting performance requires an understanding of a variety of underlying processes, particularly gene flow and selection, which can be measured, at least in part, using surrogates such as neutral...
Authors
S.E. Travis, J.B. Grace
On the specification of structural equation models for ecological systems On the specification of structural equation models for ecological systems
The use of structural equation modeling (SEM) is often motivated by its utility for investigating complex networks of relationships, but also because of its promise as a means of representing theoretical concepts using latent variables. In this paper, we discuss characteristics of ecological theory and some of the challenges for proper specification of theoretical ideas in structural...
Authors
James B. Grace, T. Michael Anderson, Han Olff, S.M. Scheiner
Climate change effects on an endemic-rich edaphic flora: resurveying Robert H. Whittaker's Siskiyou sites (Oregon, USA) Climate change effects on an endemic-rich edaphic flora: resurveying Robert H. Whittaker's Siskiyou sites (Oregon, USA)
Species with relatively narrow niches, such as plants restricted (endemic) to particular soils, may be especially vulnerable to extinction under a changing climate due to the enhanced difficulty they face in migrating to suitable new sites. To test for community-level effects of climate change, and to compare such effects in a highly endemic-rich flora on unproductive serpentine soils vs...
Authors
Ellen Ingman Damschen, Susan Harrison, James B. Grace
Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin
Federal land management agencies have invested heavily in seeding vegetation for emergency stabilization and rehabilitation (ES&R) of non-forested lands. ES&R projects are implemented to reduce post-fire dominance of non-native annual grasses, minimize probability of recurrent fire, quickly recover lost habitat for sensitive species, and ultimately result in plant communities with...
Authors
David A. Pyke, David S. Pilliod, Jeanne C. Chambers, Matthew L. Brooks, James Grace
Local versus landscape-scale effects of savanna trees on grasses Local versus landscape-scale effects of savanna trees on grasses
1. Savanna ecosystems – defined by the coexistence of trees and grasses – cover more than one‐fifth the world’s land surface and harbour most of the world’s rangelands, livestock and large mammal diversity. Savanna trees can have a variety of effects on grasses, with consequences for the wild and domestic herbivores that depend on them. 2. Studies of these effects have focused on two...
Authors
Corinna Riginos, James B. Grace, David J. Augustine, Truman P. Young
Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles
Many low‐elevation dry forests of the western United States contain more small trees and fewer large trees, more down woody debris, and less diverse and vigorous understory plant communities compared to conditions under historical fire regimes. These altered structural conditions may contribute to increased probability of unnaturally severe wildfires, susceptibility to uncharacteristic...
Authors
A. Youngblood, J.B. Grace, J.D. Mciver
Untangling the biological contributions to soil stability in semiarid shrublands Untangling the biological contributions to soil stability in semiarid shrublands
Communities of plants, biological soil crusts (BSCs), and arbuscular mycorrhizal (AM) fungi are known to influence soil stability individually, but their relative contributions, interactions, and combined effects are not well understood, particularly in arid and semiarid ecosystems. In a landscape-scale field study we quantified plant, BSC, and AM fungal communities at 216 locations...
Authors
V. Bala Chaudhary, Matthew A. Bowker, Thomas E. O’Dell, James B. Grace, Andrea E. Redman, Matthias C. Rillig, Nancy C. Johnson
Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise
1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise...
Authors
J. A. Cherry, K.L. McKee, J.B. Grace
Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests
Aim: Species richness has been observed to increase with productivity at large spatial scales, though the strength of this relationship varies among functional groups. In forests, canopy trees shade understorey plants, and for this reason we hypothesize that species richness of canopy trees will depend on macroclimate, while species richness of shorter growth forms will additionally be...
Authors
B. Oberle, J.B. Grace, J.M. Chase
Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise
1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise...
Authors
J. A. Cherry, K.L. McKee, J.B. Grace
Rank clocks and plant community dynamics Rank clocks and plant community dynamics
Summarizing complex temporal dynamics in communities is difficult to achieve in a way that yields an intuitive picture of change. Rank clocks and rank abundance statistics provide a graphical and analytical framework for displaying and quantifying community dynamics. We used rank clocks, in which the rank order abundance for each species is plotted over time in temporal clockwise...
Authors
Scott L. Collins, Katherine Suding, Elsa E. Cleland, Michael Batty, Steven C. Pennings, K.L. Gross, James B. Grace, L. Gough, Joe E. Fargione, Christopher M. Clark
Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects
Herbivores choose their habitats both to maximize forage intake and to minimize their risk of predation. For African savanna herbivores, the available habitats range in woody cover from open areas with few trees to dense, almost‐closed woodlands. This variation in woody cover or density can have a number of consequences for herbaceous species composition, cover, and productivity, as well...
Authors
Corinna Riginos, 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
Predicting performance for ecological restoration: A case study using Spartina altemiflora Predicting performance for ecological restoration: A case study using Spartina altemiflora
The success of population-based ecological restoration relies on the growth and reproductive performance of selected donor materials, whether consisting of whole plants or seed. Accurately predicting performance requires an understanding of a variety of underlying processes, particularly gene flow and selection, which can be measured, at least in part, using surrogates such as neutral...
Authors
S.E. Travis, J.B. Grace
On the specification of structural equation models for ecological systems On the specification of structural equation models for ecological systems
The use of structural equation modeling (SEM) is often motivated by its utility for investigating complex networks of relationships, but also because of its promise as a means of representing theoretical concepts using latent variables. In this paper, we discuss characteristics of ecological theory and some of the challenges for proper specification of theoretical ideas in structural...
Authors
James B. Grace, T. Michael Anderson, Han Olff, S.M. Scheiner
Climate change effects on an endemic-rich edaphic flora: resurveying Robert H. Whittaker's Siskiyou sites (Oregon, USA) Climate change effects on an endemic-rich edaphic flora: resurveying Robert H. Whittaker's Siskiyou sites (Oregon, USA)
Species with relatively narrow niches, such as plants restricted (endemic) to particular soils, may be especially vulnerable to extinction under a changing climate due to the enhanced difficulty they face in migrating to suitable new sites. To test for community-level effects of climate change, and to compare such effects in a highly endemic-rich flora on unproductive serpentine soils vs...
Authors
Ellen Ingman Damschen, Susan Harrison, James B. Grace
Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin
Federal land management agencies have invested heavily in seeding vegetation for emergency stabilization and rehabilitation (ES&R) of non-forested lands. ES&R projects are implemented to reduce post-fire dominance of non-native annual grasses, minimize probability of recurrent fire, quickly recover lost habitat for sensitive species, and ultimately result in plant communities with...
Authors
David A. Pyke, David S. Pilliod, Jeanne C. Chambers, Matthew L. Brooks, James Grace
Local versus landscape-scale effects of savanna trees on grasses Local versus landscape-scale effects of savanna trees on grasses
1. Savanna ecosystems – defined by the coexistence of trees and grasses – cover more than one‐fifth the world’s land surface and harbour most of the world’s rangelands, livestock and large mammal diversity. Savanna trees can have a variety of effects on grasses, with consequences for the wild and domestic herbivores that depend on them. 2. Studies of these effects have focused on two...
Authors
Corinna Riginos, James B. Grace, David J. Augustine, Truman P. Young
Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles
Many low‐elevation dry forests of the western United States contain more small trees and fewer large trees, more down woody debris, and less diverse and vigorous understory plant communities compared to conditions under historical fire regimes. These altered structural conditions may contribute to increased probability of unnaturally severe wildfires, susceptibility to uncharacteristic...
Authors
A. Youngblood, J.B. Grace, J.D. Mciver
Untangling the biological contributions to soil stability in semiarid shrublands Untangling the biological contributions to soil stability in semiarid shrublands
Communities of plants, biological soil crusts (BSCs), and arbuscular mycorrhizal (AM) fungi are known to influence soil stability individually, but their relative contributions, interactions, and combined effects are not well understood, particularly in arid and semiarid ecosystems. In a landscape-scale field study we quantified plant, BSC, and AM fungal communities at 216 locations...
Authors
V. Bala Chaudhary, Matthew A. Bowker, Thomas E. O’Dell, James B. Grace, Andrea E. Redman, Matthias C. Rillig, Nancy C. Johnson
Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise
1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise...
Authors
J. A. Cherry, K.L. McKee, J.B. Grace
Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests
Aim: Species richness has been observed to increase with productivity at large spatial scales, though the strength of this relationship varies among functional groups. In forests, canopy trees shade understorey plants, and for this reason we hypothesize that species richness of canopy trees will depend on macroclimate, while species richness of shorter growth forms will additionally be...
Authors
B. Oberle, J.B. Grace, J.M. Chase
Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise
1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise...
Authors
J. A. Cherry, K.L. McKee, J.B. Grace
Rank clocks and plant community dynamics Rank clocks and plant community dynamics
Summarizing complex temporal dynamics in communities is difficult to achieve in a way that yields an intuitive picture of change. Rank clocks and rank abundance statistics provide a graphical and analytical framework for displaying and quantifying community dynamics. We used rank clocks, in which the rank order abundance for each species is plotted over time in temporal clockwise...
Authors
Scott L. Collins, Katherine Suding, Elsa E. Cleland, Michael Batty, Steven C. Pennings, K.L. Gross, James B. Grace, L. Gough, Joe E. Fargione, Christopher M. Clark
Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects
Herbivores choose their habitats both to maximize forage intake and to minimize their risk of predation. For African savanna herbivores, the available habitats range in woody cover from open areas with few trees to dense, almost‐closed woodlands. This variation in woody cover or density can have a number of consequences for herbaceous species composition, cover, and productivity, as well...
Authors
Corinna Riginos, James B. Grace