Glenn is a Research Ecologist at the Eastern Ecological Science Center in Laurel, MD.
Science and Products
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...
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...
Vulnerability Assessment of Available Habitat for Wintering Black Ducks within the Refuge System in the Chesapeake Bay
American black duck (Anas rubripes) utilize inland and tidal freshwater and brackish marshes throughout the Chesapeake Bay and are considered to be an indicator species of the ecosystem’s health. Thus, conserving and increasing black duck habitats will subsequently benefit the general health of the bay. The goal of this study was to create a mechanistic model to determine the amount of...
Hurricane Sandy Impacts on Coastal Wetland Resilience in the Northeast United States
The Challenge: The high winds and storm surge associated with Hurricane Sandy impacted coastal wetlands from Virginia to Maine. Understanding the ecological and geological impacts of hurricanes on coastal wetlands and their interactive effects with local conditions is important for identifying resilience of these communities to predicted global sea-level rise. Given the projected increase in...
SERAP: Assessment of Shoreline Retreat in Response to Sea Level Rise
The broad range of complex factors influencing coastal systems contribute to large uncertainties in predicting long-term sea level rise impacts. Researchers demonstrated the capabilities of a Bayesian network (BN) to predict long-term shoreline change associated with sea level rise and make quantitative assessments for predicting uncertainty. A BN was used to define relationships between driving f
Southeast Regional Assessment Project (SERAP): Assessing Global Change Impacts on Natural and Human Systems in the Southeast
The Southeastern United States spans a broad range of physiographic settings and maintains exceptionally high levels of faunal diversity. Unfortunately, many of these ecosystems are increasingly under threat due to rapid human development, and management agencies are increasingly aware of the potential effects that climate change will have on these ecosystems. Natural resource managers and conserv
Constraints on marsh response to accelerating sea level rise
Here we provide data used to report on changes in tidal marsh elevation in relation to our network of 387 fixed benchmarks in tidal marshes on four continents measured for an average of 10 years. During this period RSLR at these marshes reached on average 6.6 mm yr-1, compared to 0.34 mm yr-1 over the past millennia. While the rate of sediment accretion corresponded to RSLR, the loss of elevation
Potential landward migration of coastal wetlands in response to sea-level rise within estuarine drainage areas and coastal states of the conterminous United States
We quantified the potential area available for landward migration of tidal saline wetlands and freshwater wetlands due to sea-level rise (SLR) at the estuary scale for 166 estuarine drainage areas and at the state scale for 22 coastal states and District of Columbia. We used 2016 Coastal Change Analysis Program (C-CAP) data in combination with the future wetland migration data under the 1.5 m glob
Estuarine drainage area boundaries for the conterminous United States
To quantify the potential for landward migration at the estuary level, we developed a geospatial dataset for the conterminous United States (CONUS) that identifies the boundaries for estuarine drainage areas. Nine estuarine drainage areas in south Florida were delineated using data developed by the South Florida Water Management District (SFWMD 2018). For the rest of CONUS, we used information con
Salt Marsh Turbidity at Mockhorn Island, VA; Plum Island, MA; York River, VA; and Altamaha River, GA
We measured turbidity along transects from channel to marsh interior for 4 sites along the east coast of the United States at: Mockhorn Island, on the Eastern Shore of VA, USA; Plum Island in MA, USA; Goodwin Islands on the York River, VA USA; and the Altamaha River estuary, in GA, USA.
Environmental and Vegetation Data from Marsh-Forest Transgression Experiment at Blackwater National Wildlife Refuge, MD, USA
We conducted a field experiment at the Moneystump Swamp in the Blackwater National Wildlife Refuge in Dorchester, MD, USA to simulate a natural forest disturbance event (e.g., storm-induced flooding) by inducing the death of established trees (coastal loblolly pine, Pinus taeda) at the marsh-upland forest ecotone. There were three treatment components: Cut- where the trees were cut and removed, Gi
Changes in Organic Carbon Source and Storage with Sea Level Rise-Induced Transgression in a Chesapeake Bay Marsh
This data set includes a variety of bulk organic carbon, lignin-phenol biomarker, and sedimentation rate data from a set of sites in the Blackwater Marsh in Chesapeake Bay. At each site, a short core was taken, and all data is organized according to depth below the marsh surface. Data includes: Bulk %OC, bulk %N, atomic carbon:nitrogen ratios, stable carbon isotopes (d13C) Lignin-phenol biomarker
Water levels (November 11 2016 through November 11 2017) for four wells and Light intensity data (October 1 2015 through September 2019): from marsh to upland forest, for Moneystump Marsh, Blackwater National Wildlife Refuge, Maryland
Water levels in meters from four wells in Moneystump marsh at Blackwater National Wildlife Refuge, MD. Two wells are located in the upland forest; one well is located in the marsh-forest transition zone (ecotone); and one well is located in the marsh. Water depth of the adjacent creek is reported in meters. Data covers the time span from November 11 2016 - November 11 2017. Pressure transducer dat
Sediment Radiochemical Data from Georgia, Massachusetts and Virginia Coastal Marshes
This data release is an archive of sedimentary laboratory analytical data produced by scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) for sediment cores and surface samples collected from coastal marshes in Georgia (GA), Virginia (VA), and Massachusetts (MA). Collaborators from USGS Patuxent Wildlife Research Center (PWRC) and the Virginia
Experimental recovery rates of tidal marsh vegetation
We measured the response of plants to disturbance across a gradient in inundation times by transplanting tussocks of Schoenoplectus americanus into mesocosms of different elevation in two marsh organ platforms. Both organs were planted on April 11, 2012 and harvested on August 21, 2012. Plants in one organ were disturbed by clipping all above ground vegetation on June 20 2012 (62 days), and left u
Development of a Multimetric Index for Integrated Assessment of Salt Marsh Ecosystem Condition
Data Release for journal publication describing development of a multimetric index for assessing salt marsh condition in northeastern National Parks. This is the first application of an empirical, metric-selection algorithm to metrics from multiple trophic groups (vegetation and nekton). While MMIs derived from nekton or vegetation metrics alone were strongly correlated with human disturbance (r-v
Decomposition of plant litter in Pacific coast tidal marshes, 2014-2015
Decomposition of plant matter is one of the key processes affecting carbon cycling and storage in tidal wetlands. In this study, we evaluated the effects of factors related to climate change (temperature, inundation) and vegetation composition on rates of litter decay in seven tidal marsh sites along the Pacific coast. In 2014 we conducted manipulative experiments to test inundation effects on lit
Filter Total Items: 109
Constraints on the adjustment of tidal marshes to accelerating sea level rise
Much uncertainty exists about the vulnerability of valuable tidal marsh ecosystems to relative sea level rise. Previous assessments of resilience to sea level rise, to which marshes can adjust by sediment accretion and elevation gain, revealed contrasting results, depending on contemporary or Holocene geological data. By analyzing globally distributed contemporary data, we found that marsh sedimen
Authors
Neil Saintilan, Katya E. Kovalenko, Glenn R. Guntenspergen, Kerrylee Rogers, James C. Lynch, Donald Cahoon, Catherine E. Lovelock, Daniel A. Friess, Erica Ashe, Ken Krauss, Nicole Cormier, Tom Spencer, Janine Adams, Jacqueline Raw, Carles Ibanez, Francesco Scarton, Stijn Temmerman, Patrick Meire, Tom Maris, Karen M. Thorne, John Brazner, Gail L. Chmura, Tony Bowron, Vishmie Palepitiya Gamage, Kimberly Cressman, Charlie Endris, Christina Marconi, Pamela Marcum, Kari St. Laurent, William G. Reay, Kenneth B. Raposa, Jason A. Garwood, Nicole Kahn
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 show that
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
Atmospheric river storm flooding influences tidal marsh elevation building processes
Disturbances are a key component of ecological processes in coastal ecosystems. Investigating factors that affect tidal marsh accretion and elevation change is important, largely due to accelerating sea-level rise and the ecological and economic value of wetlands. Sediment accumulation rates, elevation change, and flooding were examined at five marshes along a riverine-tidal gradient in the northe
Authors
Karen M. Thorne, Scott Jones, Chase M. Freeman, Kevin J. Buffington, Christopher N. Janousek, Glenn R. Guntenspergen
Temperature optimum for marsh resilience and carbon accumulation revealed in a whole ecosystem warming experiment
Coastal marshes are globally important, carbon dense ecosystems simultaneously maintained and threatened by sea-level rise. Warming temperatures may increase wetland plant productivity and organic matter accumulation, but temperature-modulated feedbacks between productivity and decomposition make it difficult to assess how wetlands and their thick, organic rich soils will respond to climate warmin
Authors
Alexander J. Smith, Genevieve L. Noyce, J. Patrick Megonigal, Glenn R. Guntenspergen, Matthew L. Kirwan
Reconciling models and measurements of marsh vulnerability to sea level rise
Tidal marsh survival in the face of sea level rise (SLR) and declining sediment supply often depends on the ability of marshes to build soil vertically. However, numerical models typically predict survival under rates of SLR that far exceed field-based measurements of vertical accretion. Here, we combine novel measurements from seven U.S. Atlantic Coast marshes and data from 70 additional marshes
Authors
Daniel J. Coleman, Mark Schuerch, Stijn Temmerman, Glenn R. Guntenspergen, Christopher G. Smith, Matthew L. Kirwan
Experimental tree mortality does not induce marsh transgression in a Chesapeake Bay low-lying coastal forest
Transgression into adjacent uplands is an important global response of coastal wetlands to accelerated rates of sea level rise. “Ghost forests” mark a signature characteristic of marsh transgression on the landscape, as changes in tidal inundation and salinity cause bordering upland tree mortality, increase light availability, and the emergence of tidal marsh species due to reduced competition. To
Authors
David C Walters, Joel A. Carr, Alyssa Hockaday, Joshua A Jones, Eliza McFarland, Katya Kovalenko, Matthew L. Kirwan, Donald Cahoon, Glenn R. Guntenspergen
Changes in organic carbon source and storage with sea level rise-induced transgression in a Chesapeake Bay marsh
Organic matter (OM) accumulation in marsh soils affects marsh survival under rapid sea-level rise (SLR). This work describes the changing organic geochemistry of a salt marsh located in the Blackwater National Wildlife Refuge on the eastern shore of Chesapeake Bay that has transgressed inland with SLR over the past 35–75 years. Marsh soils and vegetation were sampled along an elevation gradient fr
Authors
Rachel Van Allen, Kathryn M. Schreiner, Glenn R. Guntenspergen, Joseph A. Carlin
Coastal marsh degradation into ponds induces irreversible elevation loss relative to sea level
Coastal marshes and their valuable ecosystem services are feared to be lost by sea level rise, yet the mechanisms of marsh degradation into ponds and potential recovery are poorly understood. We quantified and analyzed elevations of marsh surfaces and pond bottoms along a marsh loss gradient (Blackwater River, Maryland, USA). Our analyses show that ponds deepen with increasing tidal channel width
Authors
Lennert Schepers, Patrick Brennand, Matthew L. Kirwan, Glenn R. Guntenspergen, Stijn Temmerman
Modelling marsh-forest boundary transgression in response to storms and sea-level rise
The lateral extent and vertical stability of salt marshes experiencing rising sea levels depend on interacting drivers and feedbacks with potential for non‐linear behaviors. A two‐dimensional transect model was developed to examine changes in marsh and upland forest lateral extent and to explore controls on marsh inland transgression. Model behavior demonstrates limited and abrupt forest retreat w
Authors
Joel A. Carr, Glenn R. Guntenspergen, Matthew Kirwan
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–marker ho
Authors
Alice G. Yeates, James Grace, Jennifer H. Olker, Glenn R. Guntenspergen, Donald 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
Evaluating indicators of marsh vulnerability to sea level rise along a historical marsh loss gradient
Sea level rise (SLR) is threatening coastal marshes, leading to large‐scale marsh loss in several micro‐tidal systems. Early recognition of marsh vulnerability to SLR is critical in these systems to aid managers to take appropriate restoration or mitigation measures. However, it is not clear if current marsh vulnerability indicators correctly assess long‐term stability of the marsh system. In this
Authors
Lennert Schepers, Matthew Kirwan, Glenn R. Guntenspergen, Stijn Temmerman
Habitat of the endangered salt marsh harvest mouse (Reithrodontomys raviventris) in San Francisco Bay
Understanding habitat associations is vital for conservation of at‐risk marsh‐endemic wildlife species, particularly those under threat from sea level rise. We modeled environmental and habitat associations of the marsh‐endemic, Federally endangered salt marsh harvest mouse (Reithrodontomys raviventris, RERA) and co‐occurrence with eight associated small mammal species from annual trap data, 1998–
Authors
Bruce G. Marcot, Isa Woo, Karen M. Thorne, Chase M. Freeman, Glenn R. Guntenspergen
Science and Products
- Science
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...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...Vulnerability Assessment of Available Habitat for Wintering Black Ducks within the Refuge System in the Chesapeake Bay
American black duck (Anas rubripes) utilize inland and tidal freshwater and brackish marshes throughout the Chesapeake Bay and are considered to be an indicator species of the ecosystem’s health. Thus, conserving and increasing black duck habitats will subsequently benefit the general health of the bay. The goal of this study was to create a mechanistic model to determine the amount of...Hurricane Sandy Impacts on Coastal Wetland Resilience in the Northeast United States
The Challenge: The high winds and storm surge associated with Hurricane Sandy impacted coastal wetlands from Virginia to Maine. Understanding the ecological and geological impacts of hurricanes on coastal wetlands and their interactive effects with local conditions is important for identifying resilience of these communities to predicted global sea-level rise. Given the projected increase in...SERAP: Assessment of Shoreline Retreat in Response to Sea Level Rise
The broad range of complex factors influencing coastal systems contribute to large uncertainties in predicting long-term sea level rise impacts. Researchers demonstrated the capabilities of a Bayesian network (BN) to predict long-term shoreline change associated with sea level rise and make quantitative assessments for predicting uncertainty. A BN was used to define relationships between driving fSoutheast Regional Assessment Project (SERAP): Assessing Global Change Impacts on Natural and Human Systems in the Southeast
The Southeastern United States spans a broad range of physiographic settings and maintains exceptionally high levels of faunal diversity. Unfortunately, many of these ecosystems are increasingly under threat due to rapid human development, and management agencies are increasingly aware of the potential effects that climate change will have on these ecosystems. Natural resource managers and conserv - Data
Constraints on marsh response to accelerating sea level rise
Here we provide data used to report on changes in tidal marsh elevation in relation to our network of 387 fixed benchmarks in tidal marshes on four continents measured for an average of 10 years. During this period RSLR at these marshes reached on average 6.6 mm yr-1, compared to 0.34 mm yr-1 over the past millennia. While the rate of sediment accretion corresponded to RSLR, the loss of elevationPotential landward migration of coastal wetlands in response to sea-level rise within estuarine drainage areas and coastal states of the conterminous United States
We quantified the potential area available for landward migration of tidal saline wetlands and freshwater wetlands due to sea-level rise (SLR) at the estuary scale for 166 estuarine drainage areas and at the state scale for 22 coastal states and District of Columbia. We used 2016 Coastal Change Analysis Program (C-CAP) data in combination with the future wetland migration data under the 1.5 m globEstuarine drainage area boundaries for the conterminous United States
To quantify the potential for landward migration at the estuary level, we developed a geospatial dataset for the conterminous United States (CONUS) that identifies the boundaries for estuarine drainage areas. Nine estuarine drainage areas in south Florida were delineated using data developed by the South Florida Water Management District (SFWMD 2018). For the rest of CONUS, we used information conSalt Marsh Turbidity at Mockhorn Island, VA; Plum Island, MA; York River, VA; and Altamaha River, GA
We measured turbidity along transects from channel to marsh interior for 4 sites along the east coast of the United States at: Mockhorn Island, on the Eastern Shore of VA, USA; Plum Island in MA, USA; Goodwin Islands on the York River, VA USA; and the Altamaha River estuary, in GA, USA.Environmental and Vegetation Data from Marsh-Forest Transgression Experiment at Blackwater National Wildlife Refuge, MD, USA
We conducted a field experiment at the Moneystump Swamp in the Blackwater National Wildlife Refuge in Dorchester, MD, USA to simulate a natural forest disturbance event (e.g., storm-induced flooding) by inducing the death of established trees (coastal loblolly pine, Pinus taeda) at the marsh-upland forest ecotone. There were three treatment components: Cut- where the trees were cut and removed, GiChanges in Organic Carbon Source and Storage with Sea Level Rise-Induced Transgression in a Chesapeake Bay Marsh
This data set includes a variety of bulk organic carbon, lignin-phenol biomarker, and sedimentation rate data from a set of sites in the Blackwater Marsh in Chesapeake Bay. At each site, a short core was taken, and all data is organized according to depth below the marsh surface. Data includes: Bulk %OC, bulk %N, atomic carbon:nitrogen ratios, stable carbon isotopes (d13C) Lignin-phenol biomarkerWater levels (November 11 2016 through November 11 2017) for four wells and Light intensity data (October 1 2015 through September 2019): from marsh to upland forest, for Moneystump Marsh, Blackwater National Wildlife Refuge, Maryland
Water levels in meters from four wells in Moneystump marsh at Blackwater National Wildlife Refuge, MD. Two wells are located in the upland forest; one well is located in the marsh-forest transition zone (ecotone); and one well is located in the marsh. Water depth of the adjacent creek is reported in meters. Data covers the time span from November 11 2016 - November 11 2017. Pressure transducer datSediment Radiochemical Data from Georgia, Massachusetts and Virginia Coastal Marshes
This data release is an archive of sedimentary laboratory analytical data produced by scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) for sediment cores and surface samples collected from coastal marshes in Georgia (GA), Virginia (VA), and Massachusetts (MA). Collaborators from USGS Patuxent Wildlife Research Center (PWRC) and the VirginiaExperimental recovery rates of tidal marsh vegetation
We measured the response of plants to disturbance across a gradient in inundation times by transplanting tussocks of Schoenoplectus americanus into mesocosms of different elevation in two marsh organ platforms. Both organs were planted on April 11, 2012 and harvested on August 21, 2012. Plants in one organ were disturbed by clipping all above ground vegetation on June 20 2012 (62 days), and left uDevelopment of a Multimetric Index for Integrated Assessment of Salt Marsh Ecosystem Condition
Data Release for journal publication describing development of a multimetric index for assessing salt marsh condition in northeastern National Parks. This is the first application of an empirical, metric-selection algorithm to metrics from multiple trophic groups (vegetation and nekton). While MMIs derived from nekton or vegetation metrics alone were strongly correlated with human disturbance (r-vDecomposition of plant litter in Pacific coast tidal marshes, 2014-2015
Decomposition of plant matter is one of the key processes affecting carbon cycling and storage in tidal wetlands. In this study, we evaluated the effects of factors related to climate change (temperature, inundation) and vegetation composition on rates of litter decay in seven tidal marsh sites along the Pacific coast. In 2014 we conducted manipulative experiments to test inundation effects on lit - Multimedia
- Publications
Filter Total Items: 109
Constraints on the adjustment of tidal marshes to accelerating sea level rise
Much uncertainty exists about the vulnerability of valuable tidal marsh ecosystems to relative sea level rise. Previous assessments of resilience to sea level rise, to which marshes can adjust by sediment accretion and elevation gain, revealed contrasting results, depending on contemporary or Holocene geological data. By analyzing globally distributed contemporary data, we found that marsh sedimenAuthorsNeil Saintilan, Katya E. Kovalenko, Glenn R. Guntenspergen, Kerrylee Rogers, James C. Lynch, Donald Cahoon, Catherine E. Lovelock, Daniel A. Friess, Erica Ashe, Ken Krauss, Nicole Cormier, Tom Spencer, Janine Adams, Jacqueline Raw, Carles Ibanez, Francesco Scarton, Stijn Temmerman, Patrick Meire, Tom Maris, Karen M. Thorne, John Brazner, Gail L. Chmura, Tony Bowron, Vishmie Palepitiya Gamage, Kimberly Cressman, Charlie Endris, Christina Marconi, Pamela Marcum, Kari St. Laurent, William G. Reay, Kenneth B. Raposa, Jason A. Garwood, Nicole KahnMigration 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 show thatAuthorsMichael 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. SwarzenskiAtmospheric river storm flooding influences tidal marsh elevation building processes
Disturbances are a key component of ecological processes in coastal ecosystems. Investigating factors that affect tidal marsh accretion and elevation change is important, largely due to accelerating sea-level rise and the ecological and economic value of wetlands. Sediment accumulation rates, elevation change, and flooding were examined at five marshes along a riverine-tidal gradient in the northeAuthorsKaren M. Thorne, Scott Jones, Chase M. Freeman, Kevin J. Buffington, Christopher N. Janousek, Glenn R. GuntenspergenTemperature optimum for marsh resilience and carbon accumulation revealed in a whole ecosystem warming experiment
Coastal marshes are globally important, carbon dense ecosystems simultaneously maintained and threatened by sea-level rise. Warming temperatures may increase wetland plant productivity and organic matter accumulation, but temperature-modulated feedbacks between productivity and decomposition make it difficult to assess how wetlands and their thick, organic rich soils will respond to climate warminAuthorsAlexander J. Smith, Genevieve L. Noyce, J. Patrick Megonigal, Glenn R. Guntenspergen, Matthew L. KirwanReconciling models and measurements of marsh vulnerability to sea level rise
Tidal marsh survival in the face of sea level rise (SLR) and declining sediment supply often depends on the ability of marshes to build soil vertically. However, numerical models typically predict survival under rates of SLR that far exceed field-based measurements of vertical accretion. Here, we combine novel measurements from seven U.S. Atlantic Coast marshes and data from 70 additional marshesAuthorsDaniel J. Coleman, Mark Schuerch, Stijn Temmerman, Glenn R. Guntenspergen, Christopher G. Smith, Matthew L. KirwanExperimental tree mortality does not induce marsh transgression in a Chesapeake Bay low-lying coastal forest
Transgression into adjacent uplands is an important global response of coastal wetlands to accelerated rates of sea level rise. “Ghost forests” mark a signature characteristic of marsh transgression on the landscape, as changes in tidal inundation and salinity cause bordering upland tree mortality, increase light availability, and the emergence of tidal marsh species due to reduced competition. ToAuthorsDavid C Walters, Joel A. Carr, Alyssa Hockaday, Joshua A Jones, Eliza McFarland, Katya Kovalenko, Matthew L. Kirwan, Donald Cahoon, Glenn R. GuntenspergenChanges in organic carbon source and storage with sea level rise-induced transgression in a Chesapeake Bay marsh
Organic matter (OM) accumulation in marsh soils affects marsh survival under rapid sea-level rise (SLR). This work describes the changing organic geochemistry of a salt marsh located in the Blackwater National Wildlife Refuge on the eastern shore of Chesapeake Bay that has transgressed inland with SLR over the past 35–75 years. Marsh soils and vegetation were sampled along an elevation gradient frAuthorsRachel Van Allen, Kathryn M. Schreiner, Glenn R. Guntenspergen, Joseph A. CarlinCoastal marsh degradation into ponds induces irreversible elevation loss relative to sea level
Coastal marshes and their valuable ecosystem services are feared to be lost by sea level rise, yet the mechanisms of marsh degradation into ponds and potential recovery are poorly understood. We quantified and analyzed elevations of marsh surfaces and pond bottoms along a marsh loss gradient (Blackwater River, Maryland, USA). Our analyses show that ponds deepen with increasing tidal channel widthAuthorsLennert Schepers, Patrick Brennand, Matthew L. Kirwan, Glenn R. Guntenspergen, Stijn TemmermanModelling marsh-forest boundary transgression in response to storms and sea-level rise
The lateral extent and vertical stability of salt marshes experiencing rising sea levels depend on interacting drivers and feedbacks with potential for non‐linear behaviors. A two‐dimensional transect model was developed to examine changes in marsh and upland forest lateral extent and to explore controls on marsh inland transgression. Model behavior demonstrates limited and abrupt forest retreat wAuthorsJoel A. Carr, Glenn R. Guntenspergen, Matthew KirwanHurricane 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–marker hoAuthorsAlice G. Yeates, James Grace, Jennifer H. Olker, Glenn R. Guntenspergen, Donald 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 WarrenEvaluating indicators of marsh vulnerability to sea level rise along a historical marsh loss gradient
Sea level rise (SLR) is threatening coastal marshes, leading to large‐scale marsh loss in several micro‐tidal systems. Early recognition of marsh vulnerability to SLR is critical in these systems to aid managers to take appropriate restoration or mitigation measures. However, it is not clear if current marsh vulnerability indicators correctly assess long‐term stability of the marsh system. In thisAuthorsLennert Schepers, Matthew Kirwan, Glenn R. Guntenspergen, Stijn TemmermanHabitat of the endangered salt marsh harvest mouse (Reithrodontomys raviventris) in San Francisco Bay
Understanding habitat associations is vital for conservation of at‐risk marsh‐endemic wildlife species, particularly those under threat from sea level rise. We modeled environmental and habitat associations of the marsh‐endemic, Federally endangered salt marsh harvest mouse (Reithrodontomys raviventris, RERA) and co‐occurrence with eight associated small mammal species from annual trap data, 1998–AuthorsBruce G. Marcot, Isa Woo, Karen M. Thorne, Chase M. Freeman, Glenn R. Guntenspergen - News