Dr. Karen Thorne is a Research Ecologist with the USGS Western Ecological Research Center,
Her research focus is in climate change impacts to ecosystems. In particular, her work has included assessing sea-level rise and storms impacts to nearshore ecosystems, wetland ecology and wildlife. She received her Ph.D. and MS from the University of California, Davis.
Dr. Thorne's interests lie in conservation issues surrounding climate-related research that assess changes to ecosystems and wildlife. Her current focus is assessing how sea-level rise and storms impact salt marsh ecosystems and local wildlife populations. In particular, Dr. Thorne is interested in how wildlife respond to high water events and how this relates to predation and breeding success. Her research is based on field data collection methods that can be developed into climate change impact models using ArcGIS and other remote sensing tools.
RESEARCH INTERESTS
- Global Change Biology
- Coastal Ecosystems
- Wetland Ecology
- Threatened & Endangered Species
- Wildlife Biology
- Landscape Ecology
- Ecological Response Modeling
- Storm Monitoring
- Sea-level Rise Planning & Decision Support
Professional Experience
Biologist, USGS, Western Ecological Research Center, San Francisco Bay Estuary Field Station, 2005 to present
Research Associate, U.S. Fish & Wildlife Service, Fairbanks, AK, 2002 to 2005
Education and Certifications
PhD, Geography, Global Change, University of California, Davis, 2012
MSc, Geography, Environmental Studies, University of California, Davis, 2008
BS, Wildlife, Fish, & Conservation Biology, University of California, Davis 2000
Affiliations and Memberships
California Landscape Conservation Cooperative Science Team
Science and Products
Elevations of mangrove forests of Pohnpei, Micronesia
Enhancing marsh elevation using sediment augmentation: A case study from southern California, USA
Incorporation of uncertainty to improve projections of tidal wetland elevation and carbon accumulation with sea-level rise
Climate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units
Sea-level rise vulnerability of mangrove forests on the Micronesian Island of Pohnpei
Intensity of grass invasion negatively correlated with population density and age structure of an endangered dune plant across its range
Wetlands in intermittently closed estuaries can build elevations to keep pace with sea-level rise
Distribution, abundance, and genomic diversity of the endangered antioch dunes evening primrose (Oenothera deltoides subsp. howellii) surveyed in 2019
Mangrove species’ response to sea-level rise across Pohnpei, Federated States of Micronesia
Seasonal impoundment alters patterns of tidal wetland plant diversity across spatial scales
Waterfowl use of wetland habitats informs wetland restoration designs for multi‐species benefits
Short-term impact of sediment addition on plants and invertebrates in a southern California salt marsh
Wetland Carbon Working Group: Improving Methodologies and Estimates of Carbon and Greenhouse Gas Flux in Wetlands
Sea-level Rise Vulnerability of Mangrove Forests in Micronesia and the Pacific
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
Science to Inform the Management of Mangrove Ecosystems Undergoing Sea Level Rise at Ding Darling National Wildlife Refuge, Sanibel Island, Florida
The Impact of Sea-Level Rise on Coral Reef and Mangrove Interactions and the Resulting Coastal Flooding Hazards
Using Drone Imagery to Assess Impacts of the 2018 Carr Fire
The Future Resiliency of Mangrove Forests to Sea-Level Rise in the Western Pacific: Initiating a National Assessment Approach
Modeling Sea-Level Rise in San Francisco Bay Estuary
Coastal Ecosystem Response to Sea-level Rise
Supporting Informed Responses to Sea-Level Rise
Ecological Stressors - Rocky Coastlines, Mangroves, Marshes, Droughts, and Storms
Antioch Dunes evening primrose (Oenothera deltoides subsp. howellii) juvenile and adult abundance across the known range, California, USA (2019)
Tidal Wetland Elevation Projections for Five San Francisco Bay Delta Regions Using WARMER-2, 2000-2100
Soil, Plant, and Elevation Characteristics of Tidal and Managed Impounded Wetlands in Suisun Marsh, California, USA (2018-2019)
WARMER-2 Model Inputs and Projections for Three Tidal Wetland Sites Across San Francisco Bay Estuary
Mangrove Elevation and Species' Responses to Sea-level Rise Across Pohnpei, Federated States of Micronesia
LEAN-Corrected DEM for Suisun Marsh
LEAN-corrected San Francisco Bay digital elevation model, 2018
Digital elevation model outputs from wetland accreting rate model of ecosystem resilience (WARMER) at ten year intervals from 2010-2110
Science and Products
- Publications
Filter Total Items: 45
Elevations of mangrove forests of Pohnpei, Micronesia
Mangrove surface elevation is the crux of mangrove vulnerability to sea level rise. Local topography influences critical periods of tidal inundation that govern distributions of mangrove species and dictates future distributions. This study surveyed ground surface elevations of the extensive mangroves of Pohnpei, Federated States of Micronesia, integrating four survey technologies to solve issuesEnhancing marsh elevation using sediment augmentation: A case study from southern California, USA
Tidal marshes are an important component of estuaries that provide habitat for fish and wildlife, protection from flooding, recreation opportunities, and can improve water quality. Critical to maintaining these functions is vertical accretion, a key mechanism by which tidal marshes build elevation relative to local sea level. The beneficial use of dredged material to build marsh elevations in respIncorporation of uncertainty to improve projections of tidal wetland elevation and carbon accumulation with sea-level rise
Understanding the rates and patterns of tidal wetland elevation changes relative to sea-level is essential for understanding the extent of potential wetland loss over the coming years. Using an enhanced and more flexible modeling framework of an ecosystem model (WARMER-2), we explored sea-level rise (SLR) impacts on wetland elevations and carbon sequestration rates through 2100 by considering planClimate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units
Executive SummaryThe California Coastal National Monument protects islets, reefs, and rock outcropping habitats in six onshore units, including the Trinidad and Point Arena-Stornetta Units.The California Coastal National Monument provides crucial habitat for resident and migratory species of seabirds, marine mammals, and invertebrates, which includes several federally listed threatened and endangeSea-level rise vulnerability of mangrove forests on the Micronesian Island of Pohnpei
IntroductionThe mangrove forests across the Federated States of Micronesia provide critical resources and contribute to climate resilience. Locally, mangrove forests provide habitat for fish and wildlife, timber, and other cultural resources. Mangrove forests also protect Micronesian communities from tropical cyclones and tsunamis, providing a buffer against powerful waves and winds. Mangrove foreIntensity of grass invasion negatively correlated with population density and age structure of an endangered dune plant across its range
Invasive species are a global threat to ecosystem biodiversity and function; non-native grass invasion has been particularly problematic in sparsely vegetated ecosystems such as open dunes. Native plant population responses to invasion, however, are infrequently translated to landscape scales, limiting the effectiveness of these data for addressing conservation issues. We quantified population denWetlands in intermittently closed estuaries can build elevations to keep pace with sea-level rise
Sea-level rise is a threat to coastal ecosystems, which have important conservation and economic value. While marsh response to sea-level rise has been well characterized for perennially open estuaries, bar-built intermittently-closed estuaries and their sea-level rise response are seldom addressed in the literature – despite being common globally. We seek to advance the conceptual understanding oDistribution, abundance, and genomic diversity of the endangered antioch dunes evening primrose (Oenothera deltoides subsp. howellii) surveyed in 2019
Sand dune ecosystems are highly dynamic landforms found along coastlines and riverine deltas where a supply of sand-sized material is available to be delivered by aquatic and wind environments. These unique ecosystems provide habitat for a variety of endemic and rare plant and animal species. Sand dunes have been affected by human development, sand mining, and shoreline stabilization from invasiveMangrove species’ response to sea-level rise across Pohnpei, Federated States of Micronesia
Mangrove forests are likely vulnerable to accelerating sea-level rise; however, we lack the tools necessary to understand their future resilience. On the Pacific island of Pohnpei, Federated States of Micronesia, mangroves are habitat to endangered species and provide critical ecosystem services that support local communities. We developed a generalizable modeling framework for mangroves that accoSeasonal impoundment alters patterns of tidal wetland plant diversity across spatial scales
Understanding patterns of biodiversity is a key goal of ecology and is especially pressing in the current human‐caused biodiversity crisis. In wetland ecosystems, human impacts are centered around hydrologic manipulation including the common practice of wetland diking and impoundment. Constraining how wetland management influences plant biodiversity patterns across spatial scales will provide infoWaterfowl use of wetland habitats informs wetland restoration designs for multi‐species benefits
Extensive global estuarine wetland losses have prompted intensive focus on restoration of these habitats. In California, substantial tracts of freshwater, brackish and tidal wetlands have been lost. Given the anthropogenic footprint of development and urbanization in this region, wetland restoration must rely on conversion of existing habitat types rather than adding new wetlands. These restoratioShort-term impact of sediment addition on plants and invertebrates in a southern California salt marsh
The implementation and monitoring of management strategies is integral to protect coastal marshes from increased inundation and submergence under sea-level rise. Sediment addition is one such strategy in which sediment is added to marshes to raise relative elevations, decrease tidal inundation, and enhance ecosystem processes. This study looked at the plant and invertebrate community responses ove - Science
Filter Total Items: 20
Wetland Carbon Working Group: Improving Methodologies and Estimates of Carbon and Greenhouse Gas Flux in Wetlands
WARC researchers are working to quantify the impacts of future climate and land use/land cover change on greenhouse gas emissions and reductions.Sea-level Rise Vulnerability of Mangrove Forests in Micronesia and the Pacific
The USGS and partners are studying how mangrove forests in the Federated States of Micronesia may respond to sea-level rise over the coming century. Their projections will help Micronesian communities plan for the future.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...Science to Inform the Management of Mangrove Ecosystems Undergoing Sea Level Rise at Ding Darling National Wildlife Refuge, Sanibel Island, Florida
Mangroves are forested tidal wetlands that occur in tropical, sub-tropical, and warm temperate coastal regions around the world. Mangroves occupy a significant area of coastlines globally and provide important ecosystem services to humans and wildlife. These services include aesthetic value, storm protection, food provisioning, recreation, critical wildlife habitat, and biological carbon sequestraThe Impact of Sea-Level Rise on Coral Reef and Mangrove Interactions and the Resulting Coastal Flooding Hazards
Ecosystems such as coral reefs and mangroves provide an effective first line of defense against coastal hazards and represent a promising nature-based solution to adapt to sea-level rise. In many areas, coral reefs cause waves to break and lose energy, allowing for sediment to accumulate on the inshore portion of reef flats (i.e. the shallowest, flattest part of a reef) and mangroves to establish.Using Drone Imagery to Assess Impacts of the 2018 Carr Fire
USGS WERC’s Dr. Karen Thorne and her research team are using drone imagery to understand how the 2018 Carr Fire affected ecosystems and cultural resources. The study, a collaboration with the National Park Service (NPS), focuses on Whiskeytown National Recreation Area in northern California. The drone images will help the WERC researchers identify changes in topography, cultural sites, debris...The Future Resiliency of Mangrove Forests to Sea-Level Rise in the Western Pacific: Initiating a National Assessment Approach
Sea-level rise will eventually flood and kill many coastal mangrove trees. The loss of mangrove forests will strongly affect human populations on isolated western Pacific islands as they rely heavily on mangroves for food, such as fish, shrimp, and crabs; building materials; and fire wood. Mangroves also shelter coastal communities from the impacts of tsunamis and cyclones, are home to endangeredModeling Sea-Level Rise in San Francisco Bay Estuary
With sea level rise, how will the coastal habitats of the San Francisco Bay Estuary change over the next 100 years? Mapping and modeling studies by Dr. Karen Thorne, WERC scientists, and partners have produced scenarios for this important coastal ecosystem.Coastal Ecosystem Response to Sea-level Rise
USGS WERC’s Dr. Karen Thorne, her team of reseachers, and her partners are currently taking a local site network approach to describe current and future conditions and projected responses of coastal ecosystems to sea-level rise and other stressors. The Coastal Ecosystem Response to Climate Change (CERCC) program’s goal is to understand how ecosystems vary in their ability to keep up with sea-level...Supporting Informed Responses to Sea-Level Rise
To facilitate communication and outreach of sea level rise research results and implications, Dr. Karen Thorne and members of USGS WERC are hosting in-person workshops along the Pacific coast at different sites in Washington, Oregon, and California.Ecological Stressors - Rocky Coastlines, Mangroves, Marshes, Droughts, and Storms
Coastal estuaries that contain marshes and mangroves are currently being reshaped by changing ocean and atmospheric conditions through prolong drought, sea-level rise and increased extreme storm events. Many projected increases in sea-level are expected to result in loss of tidal wetlands and their component species. In addition, changing sediment loads, extreme tide and storm events, and shifting... - Data
Antioch Dunes evening primrose (Oenothera deltoides subsp. howellii) juvenile and adult abundance across the known range, California, USA (2019)
These datasets provide information on total plant cover, Normalized Difference Vegetation Index, and Antioch Dunes evening primrose (Oenothera deltoides subsp. howellii) abundance within grids across the subspecies' extant range in California. These data support the following publication: Jones, S.F., Kennedy, A., Freeman, C.M. et al. Intensity of grass invasion negatively correlated with pTidal Wetland Elevation Projections for Five San Francisco Bay Delta Regions Using WARMER-2, 2000-2100
Projections of marsh elevation change with WARMER-2 across five regions of the San Francisco Bay Delta (Cache Yolo, South Delta, North Delta, Central Delta, and Suisun). The model was run across a range of initial elevations for each region and for scenarios of sea-level rise (30, 61, 91, 122, 152, 183, 305 cm by 2100), sediment availability (historic, constant, declining, and increase), and withSoil, Plant, and Elevation Characteristics of Tidal and Managed Impounded Wetlands in Suisun Marsh, California, USA (2018-2019)
These datasets provide information on soil properties, plant species cover, and soil surface elevation in a tidal wetland and a managed impounded wetland in northern Suisun Marsh, California, USA. These data support the following publication: Jones, S.F., Schutte, C.A., Roberts, B.J. and Thorne, K.M., 2022. Seasonal impoundment management reduces nitrogen cycling but not resilience to surfaWARMER-2 Model Inputs and Projections for Three Tidal Wetland Sites Across San Francisco Bay Estuary
Understanding the rates and patterns of tidal wetland elevation changes relative to sea-level is essential for understanding the extent of potential wetland loss over the coming years. Using an enhanced and more flexible modeling framework of an ecosystem model (WARMER-2), we explored sea-level rise (SLR) impacts on wetland elevations and carbon sequestration rates through 2100 by considering planMangrove Elevation and Species' Responses to Sea-level Rise Across Pohnpei, Federated States of Micronesia
Future sea-level rise poses a risk to mangrove forests. To better understand potential vulnerability, we developed a new numerical model of soil elevation for mangrove forests. We used the model to generate projections of elevation and mangrove forest composition change under four sea-level rise scenarios through 2100 (37, 52, 67, and 117 cm by 2100). We employed a data-driven modeling approach, uLEAN-Corrected DEM for Suisun Marsh
Lidar-derived digital elevation models often contain a vertical bias due to vegetation. In areas with tidal influence the amount of bias can be ecologically significant, for example, by decreasing the expected inundation frequency. We generated a corrected digital elevation mode (DEM) for Suisun marsh using a modification of the Lidar Elevation Adjustment with NDVI (LEAN) technique (Buffington etLEAN-corrected San Francisco Bay digital elevation model, 2018
Lidar-derived digital elevation models often contain a vertical bias due to vegetation. In areas with tidal influence the amount of bias can be ecologically significant, for example, by decreasing the expected inundation frequency. We generated a corrected digital elevation mode (DEM) for tidal marsh areas around San Francisco Bay using the Lidar Elevation Adjustment with NDVI (LEAN) technique (BuDigital elevation model outputs from wetland accreting rate model of ecosystem resilience (WARMER) at ten year intervals from 2010-2110
Digital elevation model outputs from wetland accreting rate model of ecosystem resilience (WARMER) at ten year intervals from 2010-2110. Baseline elevations were collected with RTK GPS units and LiDAR elevations in non-surveyed areas were also corrected using LEAN method. Historical accretion rates were collected at each salt marsh and used to parameterize WARMER, predicting future elevations. - Multimedia
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