Nukuhou coastal wetland. A tidal wetland with grey mangroves (Avicennia marina) and salt marsh threatened by sea level rise. At Ohiwa Harbor, North Island, New Zealand.
Glenn Guntenspergen, Ph.D.
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 response of coastal wetlands to sea-level rise: Understanding how macroscale drivers influence local processes and feedbacks
Development of a Multimetric Index for Integrated Assessment of Salt Marsh Condition in the Northeast Coastal and Barrier Network
Improving Our Ability to Forecast Tidal Marsh Response to Sea Level Rise
Vulnerability Assessment of Available Habitat for Wintering Black Ducks within the Refuge System in the Chesapeake Bay
Hurricane Sandy Impacts on Coastal Wetland Resilience in the Northeast United States
SERAP: Assessment of Shoreline Retreat in Response to Sea Level Rise
Southeast Regional Assessment Project (SERAP): Assessing Global Change Impacts on Natural and Human Systems in the Southeast
Estuarine vegetated wetland change scenarios for estuaries in the conterminous United States, 1996–2019
Constraints on marsh response to accelerating sea level rise
Potential landward migration of coastal wetlands in response to sea-level rise within estuarine drainage areas and coastal states of the conterminous United States
Estuarine drainage area boundaries for the conterminous United States
Salt Marsh Turbidity at Mockhorn Island, VA; Plum Island, MA; York River, VA; and Altamaha River, GA
Environmental and Vegetation Data from Marsh-Forest Transgression Experiment at Blackwater National Wildlife Refuge, MD, USA
Changes in Organic Carbon Source and Storage with Sea Level Rise-Induced Transgression in a Chesapeake Bay Marsh
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
Sediment Radiochemical Data from Georgia, Massachusetts and Virginia Coastal Marshes
Experimental recovery rates of tidal marsh vegetation
Development of a Multimetric Index for Integrated Assessment of Salt Marsh Ecosystem Condition
Decomposition of plant litter in Pacific coast tidal marshes, 2014-2015
Nukuhou coastal wetland. A tidal wetland with grey mangroves (Avicennia marina) and salt marsh threatened by sea level rise. At Ohiwa Harbor, North Island, New Zealand.
Aerial view of shrub mangrove forest in Rangaunu Harbour expanding into coast salt marsh and threatening to move into agricultural land because of sea level rise.
Aerial view of shrub mangrove forest in Rangaunu Harbour expanding into coast salt marsh and threatening to move into agricultural land because of sea level rise.
Omaha-Taniko Scientific Preserve. An extensive saltmarsh area in the Whangateau Harbour that has a rare intact vegetation sequence from mangrove forest and scrub ecosystem to saltmarsh to the Mānuka-dominated scrub wetland to Kahikatea swamp forest.
Omaha-Taniko Scientific Preserve. An extensive saltmarsh area in the Whangateau Harbour that has a rare intact vegetation sequence from mangrove forest and scrub ecosystem to saltmarsh to the Mānuka-dominated scrub wetland to Kahikatea swamp forest.
To adapt to rising sea levels, coastal wetlands can migrate landward at the expense of adjacent freshwater wetlands and upland ecosystems, but migration can be hindered by natural and anthropogenic barriers. This photo shows marsh migration into an upland forest in Maryland.
To adapt to rising sea levels, coastal wetlands can migrate landward at the expense of adjacent freshwater wetlands and upland ecosystems, but migration can be hindered by natural and anthropogenic barriers. This photo shows marsh migration into an upland forest in Maryland.
Understanding marsh elevation and accretion processes and vulnerability to rising sea levels across climatic and geomorphic gradients in California, USA
Observing coastal wetland transitions using national land cover products
Foundations of modeling resilience of tidal saline wetlands to sea-level rise along the U.S. Pacific Coast
Future marsh evolution due to tidal changes induced by human adaptation to sea level rise
Spatial distribution of elevation change monitoring in coastal wetlands across protected lands of the lower 48 United States
Nonlinear patterns of surface elevation change in coastal wetlands: The value of generalized additive models for quantifying rates of change
Comparing wetland elevation change using a surface elevation table, digital level, and total station
Constraints on the adjustment of tidal marshes to accelerating sea level rise
Migration and transformation of coastal wetlands in response to rising seas
Atmospheric river storm flooding influences tidal marsh elevation building processes
Temperature optimum for marsh resilience and carbon accumulation revealed in a whole ecosystem warming experiment
Reconciling models and measurements of marsh vulnerability to sea level rise
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
Estuarine vegetated wetland change scenarios for estuaries in the conterminous United States, 1996–2019
This data release contains land cover-derived statistics regarding estuarine vegetated wetland area change within estuary drainage areas along the conterminous U.S. This dataset includes net change in estuarine vegetated wetland area based on National Oceanic and Atmospheric Administration's (NOAA) Coastal Change Assessment Program (C-CAP) 1996 and 2016 land cover data. Net change was assessed betConstraints 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
New Zealand coastal wetland
Nukuhou coastal wetland. A tidal wetland with grey mangroves (Avicennia marina) and salt marsh threatened by sea level rise. At Ohiwa Harbor, North Island, New Zealand.
Nukuhou coastal wetland. A tidal wetland with grey mangroves (Avicennia marina) and salt marsh threatened by sea level rise. At Ohiwa Harbor, North Island, New Zealand.
Shrub Mangrove Forest in Rangaunu Harbour, New ZealandShrub Mangrove Forest in Rangaunu Harbour, New ZealandAerial view of shrub mangrove forest in Rangaunu Harbour expanding into coast salt marsh and threatening to move into agricultural land because of sea level rise.
Aerial view of shrub mangrove forest in Rangaunu Harbour expanding into coast salt marsh and threatening to move into agricultural land because of sea level rise.
Omaha-Taniko Scientific Preserve, New ZealandOmaha-Taniko Scientific Preserve. An extensive saltmarsh area in the Whangateau Harbour that has a rare intact vegetation sequence from mangrove forest and scrub ecosystem to saltmarsh to the Mānuka-dominated scrub wetland to Kahikatea swamp forest.
Omaha-Taniko Scientific Preserve. An extensive saltmarsh area in the Whangateau Harbour that has a rare intact vegetation sequence from mangrove forest and scrub ecosystem to saltmarsh to the Mānuka-dominated scrub wetland to Kahikatea swamp forest.
Marsh Migration Upland Forest MarylandTo adapt to rising sea levels, coastal wetlands can migrate landward at the expense of adjacent freshwater wetlands and upland ecosystems, but migration can be hindered by natural and anthropogenic barriers. This photo shows marsh migration into an upland forest in Maryland.
To adapt to rising sea levels, coastal wetlands can migrate landward at the expense of adjacent freshwater wetlands and upland ecosystems, but migration can be hindered by natural and anthropogenic barriers. This photo shows marsh migration into an upland forest in Maryland.
- Publications
Filter Total Items: 116
Understanding marsh elevation and accretion processes and vulnerability to rising sea levels across climatic and geomorphic gradients in California, USA
Tidal marshes build elevations by below- and aboveground organic and mineral soil processes. Marsh elevation and accretion data can be used to determine if marshes are keeping pace with sea-level rise. Using a network of 54 deep rod surface elevation tables with paired feldspar marker horizon plots, we tracked elevation and accretion trends across 16 marshes in California, USA. All sites had overaAuthorsKaren M. Thorne, Mckenna Leigh Bristow, Lyndsay Lee Rankin, Katya E. Kovalenko, Justine Annaliese Neville, Chase M. Freeman, Glenn R. GuntenspergenObserving coastal wetland transitions using national land cover products
Over the coming century, climate change and sea-level rise are predicted to cause widespread change to coastal wetlands. Estuarine vegetated wetlands can adapt to sea-level rise through both vertical development (i.e., biophysical feedbacks and sedimentation) and upslope/horizontal migration. Quantifying changes to estuarine vegetated wetlands over time can help to inform current and future decisiAuthorsNicholas Enwright, Michael Osland, Karen M. Thorne, Glenn R. Guntenspergen, James Grace, Gregory Steyer, Nate Herold, Bogdan Chivoiu, Minoo HanFoundations of modeling resilience of tidal saline wetlands to sea-level rise along the U.S. Pacific Coast
Context Tidal saline wetlands (TSWs) are highly threatened from climate-change effects of sea-level rise. Studies of TSWs along the East Coast U.S. and elsewhere suggest significant likely losses over coming decades but needed are analytic tools gauged to Pacific Coast U.S. wetlands.Objectives We predict the impacts of sea-level rise (SLR) on the elevation capital (vertical) and migration potentiaAuthorsBruce G. Marcot, Karen M. Thorne, Joel A. Carr, Glenn R. GuntenspergenFuture marsh evolution due to tidal changes induced by human adaptation to sea level rise
With sea level rise threatening coastal development, decision-makers are beginning to act by modifying shorelines. Previous research has shown that hardening or softening shorelines may change the tidal range under future sea level rise. Tidal range can also be changed by natural factors. Coastal marshes, which humans increasingly depend on for shoreline protection, are ecologically sensitive to tAuthorsCelina Balderas-Guzman, Kevin J. Buffington, Karen M. Thorne, Glenn R. Guntenspergen, Michelle A. Hummel, Mark T. StaceySpatial distribution of elevation change monitoring in coastal wetlands across protected lands of the lower 48 United States
IntroductionTidally influenced coastal wetlands, both saline and fresh, appear where terrestrial and marine environments meet and are considered important ecosystems for identifying the impacts of climate change. Coastal wetlands provide valuable benefits to society and the environment in the form of flood protection, water-quality improvements, and shoreline erosion reduction, making them one ofAuthorsJustine Annaliese Neville, Glenn R. GuntenspergenNonlinear patterns of surface elevation change in coastal wetlands: The value of generalized additive models for quantifying rates of change
In the face of accelerating climate change and rising sea levels, quantifying surface elevation change dynamics in coastal wetlands can help to develop a more complete understanding of the implications of sea-level rise on coastal wetland stability. The surface elevation table-marker horizon (SET-MH) approach has been widely used to quantify and characterize surface elevation change dynamics in coAuthorsLaura Feher, Michael Osland, Darren Johnson, James Grace, Glenn R. Guntenspergen, David R. Stewart, Carlos A. Coronado-Molina, Fred H. SklarComparing wetland elevation change using a surface elevation table, digital level, and total station
The surface elevation table (SET) approach and two survey instruments, a digital level (DL) and a total station (TS), were used to evaluate elevation change at a 1-ha, micro-tidal, back-barrier salt marsh at Assateague Island National Seashore (Berlin, MD, USA) from 2016 to 2022. SET data were collected at 3 sampling stations along the perimeter of the plot, 36 pins per station, and the DL and TSAuthorsJames C. Lynch, Neil Winn, Katya Kovalenko, Glenn R. GuntenspergenConstraints 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. SwarzenskiByEcosystems Mission Area, Water Resources Mission Area, Climate Research and Development Program, Land Management Research Program, Eastern Ecological Science Center, Lower Mississippi-Gulf Water Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center , Gulf of MexicoAtmospheric 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. Kirwan - News