Neal J Pastick, PhD (Former Employee)
Science and Products
Filter Total Items: 24
Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, May 2021, v1 Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, May 2021, v1
This dataset provides early estimates of 2021 exotic annual grasses (EAG) fractional cover predicted on May 3rd. We develop and release EAG fractional cover map with an emphasis on cheatgrass (Bromus tectrorum) but it also includes number of other species, i.e., Bromus arvensis L., Bromus briziformis, Bromus catharticus Vahl, Bromus commutatus, Bromus diandrus, Bromus hordeaceus L...
Weekly cloud free Harmonized Landsat Sentinel-2 (HLS) Normalized Difference Vegetation Index (NDVI) data for western United States (2016 – 2019). Weekly cloud free Harmonized Landsat Sentinel-2 (HLS) Normalized Difference Vegetation Index (NDVI) data for western United States (2016 – 2019).
In support of mapping ecological conditions (e.g. invasive annual grass) in sagebrush-dominated landscapes of the western United States, we developed weekly (starting from week 7 to week 42 and Week 1 starts January 1 or Day of the year 1 to 7, week 2 is from Day of year 8 to 14, and so on) 30-m cloud-free Normalized Difference Vegetation Index (NDVI) from 2016 to 2019. The data was...
Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2015 Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2015
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Alaska permafrost characterization: Geophysical and related field data collected from 2019-2020 Alaska permafrost characterization: Geophysical and related field data collected from 2019-2020
Geophysical measurements were collected by the U.S. Geological Survey (USGS) at two sites in Interior Alaska in 2019 and 2020 for the purposes of imaging permafrost structure and quantifying variations in subsurface moisture content in relation to thaw features. In September 2019, electrical resistivity tomography (ERT) and downhole nuclear magnetic resonance (NMR) data were used to...
Near real time estimation of annual exotic herbaceous fractional cover in the sagebrush ecosystem 30m, USA, July 2020 Near real time estimation of annual exotic herbaceous fractional cover in the sagebrush ecosystem 30m, USA, July 2020
The dataset provides a near real time estimation of 2020 herbaceous mostly annual fractional cover predicted on July 1st with an emphasis on annual exotic grasses Historically, similar maps were produced at a spatial resolution of 250m (Boyte et al. 2019 https://doi.org/10.5066/P96PVZIF., Boyte et al. 2018 https://doi.org/10.5066/P9RIV03D.), but starting this year we are mapping at a 30m
Fractional estimates of exotic annual grass cover in dryland ecosystems of western United States (2016 - 2019) Fractional estimates of exotic annual grass cover in dryland ecosystems of western United States (2016 - 2019)
The dryland ecosystems of the western United States have been invaded by exotic annual grasses, such as cheatgrass (Bromus tectorum L.), that has promoted increased fire activity and reduced biodiversity detrimental to socio-environmental systems. The use of remote sensing tools to monitor exotic annual grass cover and dynamics over large areas can support early detection and rapid...
Early estimates of Annual Exotic Herbaceous Fractional Cover in the Sagebrush Ecosystem, USA, May 2020 Early estimates of Annual Exotic Herbaceous Fractional Cover in the Sagebrush Ecosystem, USA, May 2020
The dataset provides an estimate of 2020 herbaceous mostly annual fractional cover predicted on May 1st with an emphasis on annual exotic grasses Historically, similar maps were produced at a spatial resolution of 250m (Boyte et al. 2019 https://doi.org/10.5066/P9ZEK5M1., Boyte et al. 2018 https://doi.org/10.5066/P9KSR9Z4.), but we are now mapping at a 30m resolution (Pastick et al. 2020...
Annual Herbaceous Cover across Rangelands of the Sagebrush Biome Annual Herbaceous Cover across Rangelands of the Sagebrush Biome
Data is available on https://chohnz.users.earthengine.app/view/wga-product-comparison-means Cheatgrass (Bromus tectorum) and other invasive annual grasses represent one of the single largest threats to the health and resilience of western rangelands. To address this challenge, the Western Governors Association (WGA)-appointed Western Invasive Species Council convened a cheatgrass working...
Fractional estimates of invasive annual grass cover in dryland ecosystems of western United States (2016 - 2018) Fractional estimates of invasive annual grass cover in dryland ecosystems of western United States (2016 - 2018)
Invasive annual grasses, such as cheatgrass (Bromus tectorum L.), have proliferated in dryland ecosystems of the western United States, promoting increased fire activity and reduced biodiversity that can be detrimental to socio-environmental systems. Monitoring exotic annual grass cover and dynamics over large areas requires the use of remote sensing that can support early detection and...
Alaska permafrost characterization: Geophysical and related field data collected from 2016-2017 Alaska permafrost characterization: Geophysical and related field data collected from 2016-2017
Electrical resistivity tomography (ERT), downhole nuclear magnetic resonance (NMR), and manual permafrost-probe measurements were used to quantify permafrost characteristics along transects within several catchments in interior Alaska in late summer 2016 and 2017. Geophysical sites were chosen to coincide with additional soil, hydrologic, and geochemical measurements adjacent to various...
Alaska LandCarbon Wetland Distribution Map Alaska LandCarbon Wetland Distribution Map
This product provides regional estimates of specific wetland types (bog and fen) in Alaska. Available wetland types mapped by the National Wetlands Inventory (NWI) program were re-classed into bog, fen, and other. NWI mapping of wetlands was only done for a portion of the area so a decision tree mapping algorithm was then developed to estimate bog, fen, and other across the state of...
Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2014 Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2014
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Eyes on Earth Episode 105 – Imagery Challenges of Alaska
In this episode of Eyes on Earth, we focus on Alaska. Rich in wildlife and natural resources, not to mention its sheer size, Alaska has long been a source of fascination for remote sensing scientists. But it is also a source of frustration, with frequent cloud and snow cover and months of darkness each year. Three EROS researchers well versed in interpreting Landsat imagery from Alaska shared...
Filter Total Items: 27
Geospatial data mining for digital raster mapping Geospatial data mining for digital raster mapping
We performed an in-depth literature survey to identify the most popular data mining approaches that have been applied for raster mapping of ecological parameters through the use of Geographic Information Systems (GIS) and remotely sensed data. Popular data mining approaches included decision trees or “data mining” trees which consist of regression and classification trees, random forests...
Authors
Bruce K. Wylie, Neal J. Pastick, Joshua J. Picotte, Carol Deering
Spatiotemporal remote sensing of ecosystem change and causation across Alaska Spatiotemporal remote sensing of ecosystem change and causation across Alaska
Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio‐environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high‐latitude ecosystems. Here we
Authors
Neal J. Pastick, M. Torre Jorgenson, Scott J. Goetz, Benjamin M. Jones, Bruce K. Wylie, Burke J. Minsley, Hélène Genet, Joseph F. Knight, David K. Swanson, Janet C. Jorgenson
Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA
Disturbance related to fire or hydrologic processes can cause degradation of deep (greater than 1 m) permafrost. These changes in deep permafrost have the potential to impact landscapes and infrastructure, alter the routing and distribution of surface water or groundwater, and may contribute to the flux of carbon to terrestrial and aquatic ecosystems. However, characterization of deep...
Authors
Burke J. Minsley, Benjamin R. Bloss, Brian A. Ebel, David Matthew Rey, Michelle A. Walvoord, Dana R.N. Brown, Ronald Daanen, Abraham M. Emond, M. Andy Kass, Neal J. Pastick, Bruce Wylie
Assessing historical and projected carbon balance of Alaska: A synthesis of results and policy/management implications Assessing historical and projected carbon balance of Alaska: A synthesis of results and policy/management implications
We summarize the results of a recent interagency assessment of land carbon dynamics in Alaska, in which carbon dynamics were estimated for all major terrestrial and aquatic ecosystems for the historical period (1950–2009) and a projection period (2010–2099). Between 1950 and 2009, upland and wetland (i.e., terrestrial) ecosystems of the state gained 0.4 Tg C/yr (0.1% of net primary...
Authors
A. David McGuire, Hélène Genet, Zhou Lyu, Neal J. Pastick, Sarah M. Stackpoole, Richard Birdsey, David D'Amore, Yujie He, T. Scott Rupp, Robert G. Striegl, Bruce K. Wylie, Xiaoping Zhou, Qianlai Zhuang, Zhiliang Zhu
The role of environmental driving factors in historical and projected carbon dynamics of wetland ecosystems in Alaska The role of environmental driving factors in historical and projected carbon dynamics of wetland ecosystems in Alaska
Wetlands are critical terrestrial ecosystems in Alaska, covering ~177,000 km2, an area greater than all the wetlands in the remainder of the United States. To assess the relative influence of changing climate, atmospheric carbon dioxide (CO2) concentration, and fire regime on carbon balance in wetland ecosystems of Alaska, a modeling framework that incorporates a fire disturbance model...
Authors
Zhou Lyu, Helene Genet, Yujie He, Qianlai Zhuang, A. David McGuire, Alec Bennett, Amy Breen, Joy Clein, Eugenie S. Euskirchen, Kristofer Johnson, Tom Kurkowski, Neal J. Pastick, T. Scott Rupp, Bruce K. Wylie, Zhiliang Zhu
Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems
Drylands are the habitat and source of livelihood for about two fifths of the world’s population and are highly susceptible to climate and anthropogenic change. To understand the vulnerability of drylands to changing environmental conditions, land managers need to effectively monitor rates of past change and remote sensing offers a cost-effective means to assess and manage these vast...
Authors
Neal J. Pastick, Bruce K. Wylie, Zhuoting Wu
The role of driving factors in historical and projected carbon dynamics of upland ecosystems in Alaska The role of driving factors in historical and projected carbon dynamics of upland ecosystems in Alaska
It is important to understand how upland ecosystems of Alaska, which are estimated to occupy 84% of the state (i.e., 1,237,774 km2), are influencing and will influence state‐wide carbon (C) dynamics in the face of ongoing climate change. We coupled fire disturbance and biogeochemical models to assess the relative effects of changing atmospheric carbon dioxide (CO2), climate, logging and...
Authors
Hélène Genet, Yujie He, Zhou Lyu, A. David McGuire, Qianlai Zhuang, Joy S. Clein, David D'Amore, Alec Bennett, Amy Breen, Frances Biles, Eugénie S. Euskirchen, Kristofer Johnson, Tom Kurkowski, Svetlana Schroder, Neal J. Pastick, T. Scott Rupp, Bruce K. Wylie, Yujin Zhang, Xiaoping Zhou, Zhiliang Zhu
Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska
Modern climate change in Alaska has resulted in widespread thawing of permafrost, increased fire activity, and extensive changes in vegetation characteristics that have significant consequences for socioecological systems. Despite observations of the heightened sensitivity of these systems to change, there has not been a comprehensive assessment of factors that drive ecosystem changes...
Authors
Neal J. Pastick, Paul A. Duffy, Hélène Genet, T. Scott Rupp, Bruce K. Wylie, Kristofer Johnson, M. Torre Jorgenson, Norman B. Bliss, Anthony D. McGuire, Elchin Jafarov, Joseph F. Knight
In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems
Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example) geophysical...
Authors
Mason A. Kass, Trevor P Irons, Burke J. Minsley, Neal J. Pastick, Dana R N Brown, Bruce K. Wylie
Evidence for nonuniform permafrost degradation after fire in boreal landscapes Evidence for nonuniform permafrost degradation after fire in boreal landscapes
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Authors
Burke J. Minsley, Neal J. Pastick, Bruce K. Wylie, Dana R.N. Brown, M. Andy Kass
Distribution of near-surface permafrost in Alaska: estimates of present and future conditions Distribution of near-surface permafrost in Alaska: estimates of present and future conditions
High-latitude regions are experiencing rapid and extensive changes in ecosystem composition and function as the result of increases in average air temperature. Increasing air temperatures have led to widespread thawing and degradation of permafrost, which in turn has affected ecosystems, socioeconomics, and the carbon cycle of high latitudes. Here we overcome complex interactions among...
Authors
Neal J. Pastick, M. Torre Jorgenson, Bruce K. Wylie, Shawn J. Nield, Kristofer D. Johnson, Andrew O. Finley
Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska
Quantification of aboveground biomass (AGB) in Alaska’s boreal forest is essential to the accurate evaluation of terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. Our goal was to map AGB at 30 m resolution for the boreal forest in the Yukon River Basin of Alaska using Landsat data and ground measurements. We acquired Landsat images to generate a 3-year (2008...
Authors
Lei Ji, Bruce K. Wylie, Dana R. N. Brown, Birgit E. Peterson, Heather D. Alexander, Michelle C. Mack, Jennifer R. Rover, Mark P. Waldrop, Jack W. McFarland, Xuexia Chen, Neal J. Pastick
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 24
Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, May 2021, v1 Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, May 2021, v1
This dataset provides early estimates of 2021 exotic annual grasses (EAG) fractional cover predicted on May 3rd. We develop and release EAG fractional cover map with an emphasis on cheatgrass (Bromus tectrorum) but it also includes number of other species, i.e., Bromus arvensis L., Bromus briziformis, Bromus catharticus Vahl, Bromus commutatus, Bromus diandrus, Bromus hordeaceus L...
Weekly cloud free Harmonized Landsat Sentinel-2 (HLS) Normalized Difference Vegetation Index (NDVI) data for western United States (2016 – 2019). Weekly cloud free Harmonized Landsat Sentinel-2 (HLS) Normalized Difference Vegetation Index (NDVI) data for western United States (2016 – 2019).
In support of mapping ecological conditions (e.g. invasive annual grass) in sagebrush-dominated landscapes of the western United States, we developed weekly (starting from week 7 to week 42 and Week 1 starts January 1 or Day of the year 1 to 7, week 2 is from Day of year 8 to 14, and so on) 30-m cloud-free Normalized Difference Vegetation Index (NDVI) from 2016 to 2019. The data was...
Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2015 Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2015
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Alaska permafrost characterization: Geophysical and related field data collected from 2019-2020 Alaska permafrost characterization: Geophysical and related field data collected from 2019-2020
Geophysical measurements were collected by the U.S. Geological Survey (USGS) at two sites in Interior Alaska in 2019 and 2020 for the purposes of imaging permafrost structure and quantifying variations in subsurface moisture content in relation to thaw features. In September 2019, electrical resistivity tomography (ERT) and downhole nuclear magnetic resonance (NMR) data were used to...
Near real time estimation of annual exotic herbaceous fractional cover in the sagebrush ecosystem 30m, USA, July 2020 Near real time estimation of annual exotic herbaceous fractional cover in the sagebrush ecosystem 30m, USA, July 2020
The dataset provides a near real time estimation of 2020 herbaceous mostly annual fractional cover predicted on July 1st with an emphasis on annual exotic grasses Historically, similar maps were produced at a spatial resolution of 250m (Boyte et al. 2019 https://doi.org/10.5066/P96PVZIF., Boyte et al. 2018 https://doi.org/10.5066/P9RIV03D.), but starting this year we are mapping at a 30m
Fractional estimates of exotic annual grass cover in dryland ecosystems of western United States (2016 - 2019) Fractional estimates of exotic annual grass cover in dryland ecosystems of western United States (2016 - 2019)
The dryland ecosystems of the western United States have been invaded by exotic annual grasses, such as cheatgrass (Bromus tectorum L.), that has promoted increased fire activity and reduced biodiversity detrimental to socio-environmental systems. The use of remote sensing tools to monitor exotic annual grass cover and dynamics over large areas can support early detection and rapid...
Early estimates of Annual Exotic Herbaceous Fractional Cover in the Sagebrush Ecosystem, USA, May 2020 Early estimates of Annual Exotic Herbaceous Fractional Cover in the Sagebrush Ecosystem, USA, May 2020
The dataset provides an estimate of 2020 herbaceous mostly annual fractional cover predicted on May 1st with an emphasis on annual exotic grasses Historically, similar maps were produced at a spatial resolution of 250m (Boyte et al. 2019 https://doi.org/10.5066/P9ZEK5M1., Boyte et al. 2018 https://doi.org/10.5066/P9KSR9Z4.), but we are now mapping at a 30m resolution (Pastick et al. 2020...
Annual Herbaceous Cover across Rangelands of the Sagebrush Biome Annual Herbaceous Cover across Rangelands of the Sagebrush Biome
Data is available on https://chohnz.users.earthengine.app/view/wga-product-comparison-means Cheatgrass (Bromus tectorum) and other invasive annual grasses represent one of the single largest threats to the health and resilience of western rangelands. To address this challenge, the Western Governors Association (WGA)-appointed Western Invasive Species Council convened a cheatgrass working...
Fractional estimates of invasive annual grass cover in dryland ecosystems of western United States (2016 - 2018) Fractional estimates of invasive annual grass cover in dryland ecosystems of western United States (2016 - 2018)
Invasive annual grasses, such as cheatgrass (Bromus tectorum L.), have proliferated in dryland ecosystems of the western United States, promoting increased fire activity and reduced biodiversity that can be detrimental to socio-environmental systems. Monitoring exotic annual grass cover and dynamics over large areas requires the use of remote sensing that can support early detection and...
Alaska permafrost characterization: Geophysical and related field data collected from 2016-2017 Alaska permafrost characterization: Geophysical and related field data collected from 2016-2017
Electrical resistivity tomography (ERT), downhole nuclear magnetic resonance (NMR), and manual permafrost-probe measurements were used to quantify permafrost characteristics along transects within several catchments in interior Alaska in late summer 2016 and 2017. Geophysical sites were chosen to coincide with additional soil, hydrologic, and geochemical measurements adjacent to various...
Alaska LandCarbon Wetland Distribution Map Alaska LandCarbon Wetland Distribution Map
This product provides regional estimates of specific wetland types (bog and fen) in Alaska. Available wetland types mapped by the National Wetlands Inventory (NWI) program were re-classed into bog, fen, and other. NWI mapping of wetlands was only done for a portion of the area so a decision tree mapping algorithm was then developed to estimate bog, fen, and other across the state of...
Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2014 Fire impacts on permafrost in Alaska: Geophysical and other field data collected in 2014
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Eyes on Earth Episode 105 – Imagery Challenges of Alaska
In this episode of Eyes on Earth, we focus on Alaska. Rich in wildlife and natural resources, not to mention its sheer size, Alaska has long been a source of fascination for remote sensing scientists. But it is also a source of frustration, with frequent cloud and snow cover and months of darkness each year. Three EROS researchers well versed in interpreting Landsat imagery from Alaska shared...
Filter Total Items: 27
Geospatial data mining for digital raster mapping Geospatial data mining for digital raster mapping
We performed an in-depth literature survey to identify the most popular data mining approaches that have been applied for raster mapping of ecological parameters through the use of Geographic Information Systems (GIS) and remotely sensed data. Popular data mining approaches included decision trees or “data mining” trees which consist of regression and classification trees, random forests...
Authors
Bruce K. Wylie, Neal J. Pastick, Joshua J. Picotte, Carol Deering
Spatiotemporal remote sensing of ecosystem change and causation across Alaska Spatiotemporal remote sensing of ecosystem change and causation across Alaska
Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio‐environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high‐latitude ecosystems. Here we
Authors
Neal J. Pastick, M. Torre Jorgenson, Scott J. Goetz, Benjamin M. Jones, Bruce K. Wylie, Burke J. Minsley, Hélène Genet, Joseph F. Knight, David K. Swanson, Janet C. Jorgenson
Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA
Disturbance related to fire or hydrologic processes can cause degradation of deep (greater than 1 m) permafrost. These changes in deep permafrost have the potential to impact landscapes and infrastructure, alter the routing and distribution of surface water or groundwater, and may contribute to the flux of carbon to terrestrial and aquatic ecosystems. However, characterization of deep...
Authors
Burke J. Minsley, Benjamin R. Bloss, Brian A. Ebel, David Matthew Rey, Michelle A. Walvoord, Dana R.N. Brown, Ronald Daanen, Abraham M. Emond, M. Andy Kass, Neal J. Pastick, Bruce Wylie
Assessing historical and projected carbon balance of Alaska: A synthesis of results and policy/management implications Assessing historical and projected carbon balance of Alaska: A synthesis of results and policy/management implications
We summarize the results of a recent interagency assessment of land carbon dynamics in Alaska, in which carbon dynamics were estimated for all major terrestrial and aquatic ecosystems for the historical period (1950–2009) and a projection period (2010–2099). Between 1950 and 2009, upland and wetland (i.e., terrestrial) ecosystems of the state gained 0.4 Tg C/yr (0.1% of net primary...
Authors
A. David McGuire, Hélène Genet, Zhou Lyu, Neal J. Pastick, Sarah M. Stackpoole, Richard Birdsey, David D'Amore, Yujie He, T. Scott Rupp, Robert G. Striegl, Bruce K. Wylie, Xiaoping Zhou, Qianlai Zhuang, Zhiliang Zhu
The role of environmental driving factors in historical and projected carbon dynamics of wetland ecosystems in Alaska The role of environmental driving factors in historical and projected carbon dynamics of wetland ecosystems in Alaska
Wetlands are critical terrestrial ecosystems in Alaska, covering ~177,000 km2, an area greater than all the wetlands in the remainder of the United States. To assess the relative influence of changing climate, atmospheric carbon dioxide (CO2) concentration, and fire regime on carbon balance in wetland ecosystems of Alaska, a modeling framework that incorporates a fire disturbance model...
Authors
Zhou Lyu, Helene Genet, Yujie He, Qianlai Zhuang, A. David McGuire, Alec Bennett, Amy Breen, Joy Clein, Eugenie S. Euskirchen, Kristofer Johnson, Tom Kurkowski, Neal J. Pastick, T. Scott Rupp, Bruce K. Wylie, Zhiliang Zhu
Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems Spatiotemporal analysis of Landsat-8 and Sentinel-2 data to support monitoring of dryland ecosystems
Drylands are the habitat and source of livelihood for about two fifths of the world’s population and are highly susceptible to climate and anthropogenic change. To understand the vulnerability of drylands to changing environmental conditions, land managers need to effectively monitor rates of past change and remote sensing offers a cost-effective means to assess and manage these vast...
Authors
Neal J. Pastick, Bruce K. Wylie, Zhuoting Wu
The role of driving factors in historical and projected carbon dynamics of upland ecosystems in Alaska The role of driving factors in historical and projected carbon dynamics of upland ecosystems in Alaska
It is important to understand how upland ecosystems of Alaska, which are estimated to occupy 84% of the state (i.e., 1,237,774 km2), are influencing and will influence state‐wide carbon (C) dynamics in the face of ongoing climate change. We coupled fire disturbance and biogeochemical models to assess the relative effects of changing atmospheric carbon dioxide (CO2), climate, logging and...
Authors
Hélène Genet, Yujie He, Zhou Lyu, A. David McGuire, Qianlai Zhuang, Joy S. Clein, David D'Amore, Alec Bennett, Amy Breen, Frances Biles, Eugénie S. Euskirchen, Kristofer Johnson, Tom Kurkowski, Svetlana Schroder, Neal J. Pastick, T. Scott Rupp, Bruce K. Wylie, Yujin Zhang, Xiaoping Zhou, Zhiliang Zhu
Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska
Modern climate change in Alaska has resulted in widespread thawing of permafrost, increased fire activity, and extensive changes in vegetation characteristics that have significant consequences for socioecological systems. Despite observations of the heightened sensitivity of these systems to change, there has not been a comprehensive assessment of factors that drive ecosystem changes...
Authors
Neal J. Pastick, Paul A. Duffy, Hélène Genet, T. Scott Rupp, Bruce K. Wylie, Kristofer Johnson, M. Torre Jorgenson, Norman B. Bliss, Anthony D. McGuire, Elchin Jafarov, Joseph F. Knight
In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems
Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example) geophysical...
Authors
Mason A. Kass, Trevor P Irons, Burke J. Minsley, Neal J. Pastick, Dana R N Brown, Bruce K. Wylie
Evidence for nonuniform permafrost degradation after fire in boreal landscapes Evidence for nonuniform permafrost degradation after fire in boreal landscapes
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability...
Authors
Burke J. Minsley, Neal J. Pastick, Bruce K. Wylie, Dana R.N. Brown, M. Andy Kass
Distribution of near-surface permafrost in Alaska: estimates of present and future conditions Distribution of near-surface permafrost in Alaska: estimates of present and future conditions
High-latitude regions are experiencing rapid and extensive changes in ecosystem composition and function as the result of increases in average air temperature. Increasing air temperatures have led to widespread thawing and degradation of permafrost, which in turn has affected ecosystems, socioeconomics, and the carbon cycle of high latitudes. Here we overcome complex interactions among...
Authors
Neal J. Pastick, M. Torre Jorgenson, Bruce K. Wylie, Shawn J. Nield, Kristofer D. Johnson, Andrew O. Finley
Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska
Quantification of aboveground biomass (AGB) in Alaska’s boreal forest is essential to the accurate evaluation of terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. Our goal was to map AGB at 30 m resolution for the boreal forest in the Yukon River Basin of Alaska using Landsat data and ground measurements. We acquired Landsat images to generate a 3-year (2008...
Authors
Lei Ji, Bruce K. Wylie, Dana R. N. Brown, Birgit E. Peterson, Heather D. Alexander, Michelle C. Mack, Jennifer R. Rover, Mark P. Waldrop, Jack W. McFarland, Xuexia Chen, Neal J. Pastick
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.