James Grace, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 187
A 'weight of evidence' approach to evaluating structural equation models A 'weight of evidence' approach to evaluating structural equation models
It is possible that model selection has been the most researched and most discussed topic in the history of both statistics and structural equation modeling (SEM). The reason for this is because selecting one model for interpretive use from amongst many possible models is both essential and difficult. The published protocols and advice for model evaluation and selection in SEM studies...
Authors
James Grace
Structural equation modeling Structural equation modeling
This chapter introduces background and historical information on how structural equation modeling (SEM) came to be developed. Then, the main differences between SEM and earlier multivariate methods are explained. The chapter describes three main applications of SEM: path analysis, factor analysis, and hybrid models. Some computer programs are recommended for these applications. The step...
Authors
Matt Miller, Ivana Tasic, Torrey Lyons, Reid Ewing, James B. Grace
Conceptual frameworks Conceptual frameworks
The chapter starts by addressing some of the issues that come from not using a conceptual framework. This point is illustrated using an example with causal factors. The chapter then goes on to explain the mechanics of establishing conceptual frameworks. Lastly, it lays out a step-by-step guide on how to create a framework—generating a set of concepts, specifying the relations between...
Authors
Keunhyun Park, James B. Grace, Reid Ewing
Scientist’s guide to developing explanatory statistical models using causal analysis principles Scientist’s guide to developing explanatory statistical models using causal analysis principles
Recent discussions of model selection and multimodel inference highlight a general challenge for researchers, which is how to clearly convey the explanatory content of a hypothesized model or set of competing models. The advice from statisticians for scientists employing multimodel inference is to develop a well‐thought‐out set of candidate models for comparison, though precise...
Authors
James B. Grace, Kathryn Irvine
The importance of natural versus human factors for ecological conditions of streams and rivers The importance of natural versus human factors for ecological conditions of streams and rivers
Streams are influenced by watershed-scale factors, such as climate, geology, topography, hydrology, and soils, which mostly vary naturally among sites, as well as human factors, agriculture and urban development. Thus, natural factors could complicate assessment of human disturbance. In the present study, we use structural equation modeling and data from the 2008-2009 United States...
Authors
Tao Tang, R. Stevenson, James Grace
Climatic controls on the distribution of foundation plant species in coastal wetlands of the conterminous United States: Knowledge gaps and emerging research needs Climatic controls on the distribution of foundation plant species in coastal wetlands of the conterminous United States: Knowledge gaps and emerging research needs
Foundation plant species play a critical role in coastal wetlands, often modifying abiotic conditions that are too stressful for most organisms and providing the primary habitat features that support entire ecological communities. Here, we consider the influence of climatic drivers on the distribution of foundation plant species within coastal wetlands of the conterminous USA. Using...
Authors
Michael Osland, James B. Grace, Glenn Guntenspergen, Karen Thorne, Joel Carr, Laura Feher
Discoveries and novel insights in ecology using structural equation modeling Discoveries and novel insights in ecology using structural equation modeling
As we enter the era of data science (Lortie 2018), quantitative analysis methodologies are proliferating rapidly, leaving ecologists with the task of choosing among many alternatives. The use of structural equation modeling (SEM) by ecologists has increased in recent years, prompting us to ask users a number of questions about their experience with the methodology. Responses indicate an
Authors
Daniel Laughlin, James Grace
Patterns of resource allocation in a coastal marsh plant (Schoenoplectus americanus) along a sediment-addition gradient Patterns of resource allocation in a coastal marsh plant (Schoenoplectus americanus) along a sediment-addition gradient
Reductions in sediment delivery to coastal marshes increase their vulnerability to relative sea-level rise. Sediment pulses from storm events and commercial dredge-spray operations (e.g., beneficial use) represent increasingly important sediment sources to otherwise sediment-deprived marshes. These sediments can stimulate plant growth by providing nutrient and elevation subsidies, with...
Authors
Nigel Temple, James Grace, Julia A Cherry
Hurricane Sandy impacts on coastal wetland resilience Hurricane Sandy impacts on coastal wetland resilience
The goal of this research was to evaluate the impacts of Hurricane Sandy on surface elevation trends in estuarine marshes located across the northeast region of the United States from Virginia to Maine using data from an opportunistic (in other words, not strategic) and collaborative network (from here on, an opportunistic network) of surface elevation table-marker horizon (SET-MH)...
Authors
Donald R. Cahoon, Jennifer Olker, Alice Yeates, Glenn Guntenspergen, James Grace, Susan Adamowicz, Shimon Anisfeld, Andrew Baldwin, Nels Barrett, Leah Beckett, Alice Benzecry, Linda Blum, David Burdick, William Crouch, Marci Ekberg, Sarah Fernald, Kristin Grimes, Joseph Grzyb, Ellen Hartig, Danielle Kreeger, Marit Larson, Scott Lerberg, James Lynch, Nicole Maher, Martha Maxwell-Doyle, Laura R. Mitchell, Jordan Mora, Victoria O’Neill, Angela Padeletti, Diann Prosser, Tracy Quirk, Kenneth Raposa, William Reay, Drexel Siok, Christopher Snow, Adam Starke, J. Stevenson, Lorie Staver, Vincent Turner
The plant diversity sampling design for The National Ecological Observatory Network The plant diversity sampling design for The National Ecological Observatory Network
The National Ecological Observatory Network (NEON) is designed to facilitate an understanding of the impact of environmental change on ecological systems. Observations of plant diversity—responsive to changes in climate, disturbance, and land use, and ecologically linked to soil, biogeochemistry, and organisms—result in NEON data products that cross a range of organizational levels...
Authors
David Barnett, Peter Adler, Benjamin Chemel, Paul Duffy, Brian Enquist, James Grace, Susan Harrison, Robert Peet, David Schimel, Thomas Stohlgren, Mark Vellend
Climate and plant controls on soil organic matter in coastal wetlands Climate and plant controls on soil organic matter in coastal wetlands
Coastal wetlands are among the most productive and carbon‐rich ecosystems on Earth. Long‐term carbon storage in coastal wetlands occurs primarily belowground as soil organic matter (SOM). In addition to serving as a carbon sink, SOM influences wetland ecosystem structure, function, and stability. To anticipate and mitigate the effects of climate change, there is a need to advance...
Authors
Michael Osland, Christopher A. Gabler, James Grace, Richard Day, Meagan L. McCoy, Jennie McLeod, Andrew From, Nicholas Enwright, Laura Feher, Camille Stagg, Stephen Hartley
Quantifying relative importance: Computing standardized effects in models with binary outcomes Quantifying relative importance: Computing standardized effects in models with binary outcomes
Scientists commonly ask questions about the relative importances of processes, and then turn to statistical models for answers. Standardized coefficients are typically used in such situations, with the goal being to compare effects on a common scale. Traditional approaches to obtaining standardized coefficients were developed with idealized Gaussian variables in mind. When responses are...
Authors
James Grace, Darren Johnson, Jonathan S. Lefcheck, Jarrett Byrnes
Science and Products
Filter Total Items: 187
A 'weight of evidence' approach to evaluating structural equation models A 'weight of evidence' approach to evaluating structural equation models
It is possible that model selection has been the most researched and most discussed topic in the history of both statistics and structural equation modeling (SEM). The reason for this is because selecting one model for interpretive use from amongst many possible models is both essential and difficult. The published protocols and advice for model evaluation and selection in SEM studies...
Authors
James Grace
Structural equation modeling Structural equation modeling
This chapter introduces background and historical information on how structural equation modeling (SEM) came to be developed. Then, the main differences between SEM and earlier multivariate methods are explained. The chapter describes three main applications of SEM: path analysis, factor analysis, and hybrid models. Some computer programs are recommended for these applications. The step...
Authors
Matt Miller, Ivana Tasic, Torrey Lyons, Reid Ewing, James B. Grace
Conceptual frameworks Conceptual frameworks
The chapter starts by addressing some of the issues that come from not using a conceptual framework. This point is illustrated using an example with causal factors. The chapter then goes on to explain the mechanics of establishing conceptual frameworks. Lastly, it lays out a step-by-step guide on how to create a framework—generating a set of concepts, specifying the relations between...
Authors
Keunhyun Park, James B. Grace, Reid Ewing
Scientist’s guide to developing explanatory statistical models using causal analysis principles Scientist’s guide to developing explanatory statistical models using causal analysis principles
Recent discussions of model selection and multimodel inference highlight a general challenge for researchers, which is how to clearly convey the explanatory content of a hypothesized model or set of competing models. The advice from statisticians for scientists employing multimodel inference is to develop a well‐thought‐out set of candidate models for comparison, though precise...
Authors
James B. Grace, Kathryn Irvine
The importance of natural versus human factors for ecological conditions of streams and rivers The importance of natural versus human factors for ecological conditions of streams and rivers
Streams are influenced by watershed-scale factors, such as climate, geology, topography, hydrology, and soils, which mostly vary naturally among sites, as well as human factors, agriculture and urban development. Thus, natural factors could complicate assessment of human disturbance. In the present study, we use structural equation modeling and data from the 2008-2009 United States...
Authors
Tao Tang, R. Stevenson, James Grace
Climatic controls on the distribution of foundation plant species in coastal wetlands of the conterminous United States: Knowledge gaps and emerging research needs Climatic controls on the distribution of foundation plant species in coastal wetlands of the conterminous United States: Knowledge gaps and emerging research needs
Foundation plant species play a critical role in coastal wetlands, often modifying abiotic conditions that are too stressful for most organisms and providing the primary habitat features that support entire ecological communities. Here, we consider the influence of climatic drivers on the distribution of foundation plant species within coastal wetlands of the conterminous USA. Using...
Authors
Michael Osland, James B. Grace, Glenn Guntenspergen, Karen Thorne, Joel Carr, Laura Feher
Discoveries and novel insights in ecology using structural equation modeling Discoveries and novel insights in ecology using structural equation modeling
As we enter the era of data science (Lortie 2018), quantitative analysis methodologies are proliferating rapidly, leaving ecologists with the task of choosing among many alternatives. The use of structural equation modeling (SEM) by ecologists has increased in recent years, prompting us to ask users a number of questions about their experience with the methodology. Responses indicate an
Authors
Daniel Laughlin, James Grace
Patterns of resource allocation in a coastal marsh plant (Schoenoplectus americanus) along a sediment-addition gradient Patterns of resource allocation in a coastal marsh plant (Schoenoplectus americanus) along a sediment-addition gradient
Reductions in sediment delivery to coastal marshes increase their vulnerability to relative sea-level rise. Sediment pulses from storm events and commercial dredge-spray operations (e.g., beneficial use) represent increasingly important sediment sources to otherwise sediment-deprived marshes. These sediments can stimulate plant growth by providing nutrient and elevation subsidies, with...
Authors
Nigel Temple, James Grace, Julia A Cherry
Hurricane Sandy impacts on coastal wetland resilience Hurricane Sandy impacts on coastal wetland resilience
The goal of this research was to evaluate the impacts of Hurricane Sandy on surface elevation trends in estuarine marshes located across the northeast region of the United States from Virginia to Maine using data from an opportunistic (in other words, not strategic) and collaborative network (from here on, an opportunistic network) of surface elevation table-marker horizon (SET-MH)...
Authors
Donald R. Cahoon, Jennifer Olker, Alice Yeates, Glenn Guntenspergen, James Grace, Susan Adamowicz, Shimon Anisfeld, Andrew Baldwin, Nels Barrett, Leah Beckett, Alice Benzecry, Linda Blum, David Burdick, William Crouch, Marci Ekberg, Sarah Fernald, Kristin Grimes, Joseph Grzyb, Ellen Hartig, Danielle Kreeger, Marit Larson, Scott Lerberg, James Lynch, Nicole Maher, Martha Maxwell-Doyle, Laura R. Mitchell, Jordan Mora, Victoria O’Neill, Angela Padeletti, Diann Prosser, Tracy Quirk, Kenneth Raposa, William Reay, Drexel Siok, Christopher Snow, Adam Starke, J. Stevenson, Lorie Staver, Vincent Turner
The plant diversity sampling design for The National Ecological Observatory Network The plant diversity sampling design for The National Ecological Observatory Network
The National Ecological Observatory Network (NEON) is designed to facilitate an understanding of the impact of environmental change on ecological systems. Observations of plant diversity—responsive to changes in climate, disturbance, and land use, and ecologically linked to soil, biogeochemistry, and organisms—result in NEON data products that cross a range of organizational levels...
Authors
David Barnett, Peter Adler, Benjamin Chemel, Paul Duffy, Brian Enquist, James Grace, Susan Harrison, Robert Peet, David Schimel, Thomas Stohlgren, Mark Vellend
Climate and plant controls on soil organic matter in coastal wetlands Climate and plant controls on soil organic matter in coastal wetlands
Coastal wetlands are among the most productive and carbon‐rich ecosystems on Earth. Long‐term carbon storage in coastal wetlands occurs primarily belowground as soil organic matter (SOM). In addition to serving as a carbon sink, SOM influences wetland ecosystem structure, function, and stability. To anticipate and mitigate the effects of climate change, there is a need to advance...
Authors
Michael Osland, Christopher A. Gabler, James Grace, Richard Day, Meagan L. McCoy, Jennie McLeod, Andrew From, Nicholas Enwright, Laura Feher, Camille Stagg, Stephen Hartley
Quantifying relative importance: Computing standardized effects in models with binary outcomes Quantifying relative importance: Computing standardized effects in models with binary outcomes
Scientists commonly ask questions about the relative importances of processes, and then turn to statistical models for answers. Standardized coefficients are typically used in such situations, with the goal being to compare effects on a common scale. Traditional approaches to obtaining standardized coefficients were developed with idealized Gaussian variables in mind. When responses are...
Authors
James Grace, Darren Johnson, Jonathan S. Lefcheck, Jarrett Byrnes