The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Alan A. Ager - One of the best experts on this subject based on the ideXlab platform.
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archetypes of community wildfire exposure from National Forests of the western us
Landscape and Urban Planning, 2019Co-Authors: Cody Evers, Alan A. Ager, Max Nielsenpincus, Palaiologos Palaiologou, Ken BunzelAbstract:Abstract Risk management typologies and their resulting archetypes can structure the many social and biophysical drivers of community wildfire risk into a set number of strategies to build community resilience. Existing typologies omit key factors that determine the scale and mechanism by which exposure from large wildfires occur. These factors are particularly important for land managing agencies like the US Forest Service, which must weigh community wildfire exposure against other management priorities. We analyze community wildfire exposure from National Forests by associating conditions that affect exposure in the areas where wildfires ignite to conditions where exposure likely occurs. Linking source and exposure areas defines the scale at which cross-boundary exposure from large wildfires occurs and the scale at which mitigation actions need to be planned. We find that the vast majority of wildfire exposure from National Forests is concentrated among a fraction of communities that are geographically clustered in discrete pockets. Among these communities, exposure varies primarily based on development patterns and vegetation gradients and secondarily based on social and ecological management constraints. We describe five community exposure archetypes along with their associated risk mitigation strategies. Only some archetypes have conditions that support hazardous fuels programs. Others have conditions where managing community exposure through vegetation management is unlikely to suffice. These archetypes reflect the diversity of development patterns, vegetation types, associated fuels, and management constraints that exist in the western US and provide a framework to guide public investments that improve management of wildfire risk within threatened communities and on the public lands that transmit fires to them.
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Wildfire exposure and fuel management on western US National Forests.
Journal of environmental management, 2014Co-Authors: Alan A. Ager, Michelle A. Day, Charles W. Mchugh, Karen C. Short, Julie W. Gilbertson-day, Mark A. Finney, David E. CalkinAbstract:Substantial investments in fuel management activities on National Forests in the western US are part of a National strategy to reduce human and ecological losses from catastrophic wildfire and create fire resilient landscapes. Prioritizing these investments within and among National Forests remains a challenge, partly because a comprehensive assessment that establishes the current wildfire risk and exposure does not exist, making it difficult to identify National priorities and target specific areas for fuel management. To gain a broader understanding of wildfire exposure in the National forest system, we analyzed an array of simulated and empirical data on wildfire activity and fuel treatment investments on the 82 western US National Forests. We first summarized recent fire data to examine variation among the Forests in ignition frequency and burned area in relation to investments in fuel reduction treatments. We then used simulation modeling to analyze fine-scale spatial variation in burn probability and intensity. We also estimated the probability of a mega-fire event on each of the Forests, and the transmission of fires ignited on National Forests to the surrounding urban interface. The analysis showed a good correspondence between recent area burned and predictions from the simulation models. The modeling also illustrated the magnitude of the variation in both burn probability and intensity among and within Forests. Simulated burn probabilities in most instances were lower than historical, reflecting fire exclusion on many National Forests. Simulated wildfire transmission from National Forests to the urban interface was highly variable among the Forests. We discuss how the results of the study can be used to prioritize investments in hazardous fuel reduction within a comprehensive multi-scale risk management framework.
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wildfire exposure analysis on the National Forests in the pacific northwest usa
Risk Analysis, 2013Co-Authors: Alan A. Ager, Michelle Buonopane, Allison Reger, Mark A. FinneyAbstract:We analyzed wildfire exposure for key social and ecological features on the National Forests in Oregon and Washington. The Forests contain numerous urban interfaces, old growth Forests, recreational sites, and habitat for rare and endangered species. Many of these resources are threatened by wildfire, especially in the east Cascade Mountains fire-prone Forests. The study illustrates the application of wildfire simulation for risk assessment where the major threat is from large and rare naturally ignited fires, versus many previous studies that have focused on risk driven by frequent and small fires from anthropogenic ignitions. Wildfire simulation modeling was used to characterize potential wildfire behavior in terms of annual burn probability and flame length. Spatial data on selected social and ecological features were obtained from Forest Service GIS databases and elsewhere. The potential wildfire behavior was then summarized for each spatial location of each resource. The analysis suggested strong spatial variation in both burn probability and conditional flame length for many of the features examined, including biodiversity, urban interfaces, and infrastructure. We propose that the spatial patterns in modeled wildfire behavior could be used to improve existing prioritization of fuel management and wildfire preparedness activities within the Pacific Northwest region.
Mark A. Finney - One of the best experts on this subject based on the ideXlab platform.
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Wildfire exposure and fuel management on western US National Forests.
Journal of environmental management, 2014Co-Authors: Alan A. Ager, Michelle A. Day, Charles W. Mchugh, Karen C. Short, Julie W. Gilbertson-day, Mark A. Finney, David E. CalkinAbstract:Substantial investments in fuel management activities on National Forests in the western US are part of a National strategy to reduce human and ecological losses from catastrophic wildfire and create fire resilient landscapes. Prioritizing these investments within and among National Forests remains a challenge, partly because a comprehensive assessment that establishes the current wildfire risk and exposure does not exist, making it difficult to identify National priorities and target specific areas for fuel management. To gain a broader understanding of wildfire exposure in the National forest system, we analyzed an array of simulated and empirical data on wildfire activity and fuel treatment investments on the 82 western US National Forests. We first summarized recent fire data to examine variation among the Forests in ignition frequency and burned area in relation to investments in fuel reduction treatments. We then used simulation modeling to analyze fine-scale spatial variation in burn probability and intensity. We also estimated the probability of a mega-fire event on each of the Forests, and the transmission of fires ignited on National Forests to the surrounding urban interface. The analysis showed a good correspondence between recent area burned and predictions from the simulation models. The modeling also illustrated the magnitude of the variation in both burn probability and intensity among and within Forests. Simulated burn probabilities in most instances were lower than historical, reflecting fire exclusion on many National Forests. Simulated wildfire transmission from National Forests to the urban interface was highly variable among the Forests. We discuss how the results of the study can be used to prioritize investments in hazardous fuel reduction within a comprehensive multi-scale risk management framework.
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wildfire exposure analysis on the National Forests in the pacific northwest usa
Risk Analysis, 2013Co-Authors: Alan A. Ager, Michelle Buonopane, Allison Reger, Mark A. FinneyAbstract:We analyzed wildfire exposure for key social and ecological features on the National Forests in Oregon and Washington. The Forests contain numerous urban interfaces, old growth Forests, recreational sites, and habitat for rare and endangered species. Many of these resources are threatened by wildfire, especially in the east Cascade Mountains fire-prone Forests. The study illustrates the application of wildfire simulation for risk assessment where the major threat is from large and rare naturally ignited fires, versus many previous studies that have focused on risk driven by frequent and small fires from anthropogenic ignitions. Wildfire simulation modeling was used to characterize potential wildfire behavior in terms of annual burn probability and flame length. Spatial data on selected social and ecological features were obtained from Forest Service GIS databases and elsewhere. The potential wildfire behavior was then summarized for each spatial location of each resource. The analysis suggested strong spatial variation in both burn probability and conditional flame length for many of the features examined, including biodiversity, urban interfaces, and infrastructure. We propose that the spatial patterns in modeled wildfire behavior could be used to improve existing prioritization of fuel management and wildfire preparedness activities within the Pacific Northwest region.
Jon E Keeley - One of the best experts on this subject based on the ideXlab platform.
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contrasting prescription burning and wildfires in california sierra nevada National parks and adjacent National Forests
International Journal of Wildland Fire, 2021Co-Authors: Jon E Keeley, Anne H Pfaff, Anthony C CaprioAbstract:History of prescription burning and wildfires in the three Sierra Nevada National Park Service (NPS) parks and adjacent US Forest Service (USFS) Forests is presented. Annual prescription (Rx) burns began in 1968 in Sequoia and Kings Canyon National Parks, followed by Yosemite National Park and Lassen Volcanic National Park. During the last third of the 20th century, USFS National Forests adjacent to these parks did limited Rx burns, accounting for very little area burned. However, in 2004, an aggressive annual burn program was initiated in these National Forests and in the last decade, area burned by planned prescription burns, relative to area protected, was approximately comparable between these NPS and USFS lands. In 1968, the NPS prescription burning program was unique because it coupled planned Rx burns with managing many lightning-ignited fires for resource benefit. From 1968 to 2017, these natural fires managed for resource benefit averaged the same total area burned as planned Rx burns in the three National parks; thus, they have had a substantial impact on total area burned by prescription. In contrast, on USFS lands, most lightning-ignited fires have been managed for suppression, but increasing attention is being paid to managing wildfires for resource benefit.
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comparing the role of fuel breaks across southern california National Forests
Forest Ecology and Management, 2011Co-Authors: Alexandra D Syphard, Jon E Keeley, Teresa J BrennanAbstract:Fuel treatment of wildland vegetation is the primary approach advocated for mitigating fire risk at the wildland-urban interface (WUI), but little systematic research has been conducted to understand what role fuel treatments play in controlling large fires, which factors influence this role, or how the role of fuel treatments may vary over space and time. We assembled a spatial database of fuel breaks and fires from the last 30 years in four southern California National Forests to better understand which factors are consistently important for fuel breaks in the control of large fires. We also explored which landscape features influence where fires and fuel breaks are most likely to intersect. The relative importance of significant factors explaining fuel break outcome and number of fire and fuel break intersections varied among the Forests, which reflects high levels of regional landscape diversity. Nevertheless, several factors were consistently important across all the Forests. In general, fuel breaks played an important role in controlling large fires only when they facilitated fire management, primarily by providing access for firefighting activities. Fire weather and fuel break maintenance were also consistently important. Models and maps predicting where fuel breaks and fires are most likely to intersect performed well in the regions where the models were developed, but these models did not extend well to other regions, reflecting how the environmental controls of fire regimes vary even within a single ecoregion. Nevertheless, similar mapping methods could be adopted in different landscapes to help with strategic location of fuel breaks. Strategic location of fuel breaks should also account for access points near communities, where fire protection is most important.
Yang Zhang - One of the best experts on this subject based on the ideXlab platform.
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divergence of ecosystem services in u s National Forests and grasslands under a changing climate
Scientific Reports, 2016Co-Authors: Kai Duan, Steven G Mcnulty, Ge Sun, Shanlei Sun, Peter V Caldwell, Erika Cohen, Heather Dinon Aldridge, Yang ZhangAbstract:The 170 National Forests and Grasslands (NFs) in the conterminous United States are public lands that provide important ecosystem services such as clean water and timber supply to the American people. This study investigates the potential impacts of climate change on two key ecosystem functions (i.e., water yield and ecosystem productivity) using the most recent climate projections derived from 20 Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that future climate change may result in a significant reduction in water yield but an increase in ecosystem productivity in NFs. On average, gross ecosystem productivity is projected to increase by 76 ~ 229 g C m−2 yr−1 (8% ~ 24%) while water yield is projected to decrease by 18 ~ 31 mm yr−1 (4% ~ 7%) by 2100 as a result of the combination of increased air temperature (+1.8 ~ +5.2 °C) and precipitation (+17 ~ +51 mm yr−1). The notable divergence in ecosystem services of water supply and carbon sequestration is expected to intensify under higher greenhouse gas emission and associated climate change in the future, posing greater challenges to managing NFs for both ecosystem services.
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drought impacts on ecosystem functions of the u s National Forests and grasslands part ii assessment results and management implications
Forest Ecology and Management, 2015Co-Authors: Ge Sun, Shanlei Sun, Peter V Caldwell, Erika Cohen, Steve Mcnulty, Jingfeng Xiao, Yang ZhangAbstract:The 781,000 km 2 (193 million acre) United States National Forests and Grasslands system (NF) provides important ecosystem services such as clean water supply, timber production, wildlife habitat, and recreation opportunities to the American public. Quantifying the historical impacts of climate change and drought on ecosystem functions at the National scale is essential to develop sound forest management and watershed restoration plans under a changing climate. This study applied the previously validated Water Supply and Stress Index model (WaSSI) to 170 NFs in the conterminous U.S. (CONUS) to examine how historical extreme droughts have affected forest water yield (Q) and gross primary productivity (GPP). For each NF, we focused on the five years with the lowest annual SPI3 (Standardized Precipitation Index on a 3-month time scale) during 1962–2012. The extent of extreme droughts as measured by the number of NFs and total area affected by droughts has increased during the last decade. Across all lands in CONUS, the most extreme drought during the past decade occurred in 2002, resulting in a mean reduction of Q by 32% and GPP by 20%. For the 170 individual NFs, on average, the top-five droughts represented a reduction in precipitation by 145 mm yr 1 (or 22%), causing reductions in evap
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drought impacts on ecosystem functions of the u s National Forests and grasslands part i evaluation of a water and carbon balance model
Forest Ecology and Management, 2015Co-Authors: Shanlei Sun, Steven G Mcnulty, Ge Sun, Peter V Caldwell, Erika Cohen, Jingfeng Xiao, Yang ZhangAbstract:Understanding and quantitatively evaluating the regional impacts of climate change and variability (e.g., droughts) on forest ecosystem functions (i.e., water yield, evapotranspiration, and productivity) and services (e.g., fresh water supply and carbon sequestration) is of great importance for developing climate change adaptation strategies for National Forests and Grasslands (NFs) in the United States. However, few reliable continental-scale modeling tools are available to account for both water and carbon dynamics. The objective of this study was to test a monthly water and carbon balance model, the Water Supply Stress Index (WaSSI) model, for potential application in addressing the influences of drought on NFs ecosystem services across the conterminous United States (CONUS). The performance of the WaSSI model was comprehensively assessed with measured streamflow (Q) at 72 U.S. Geological Survey (USGS) gauging stations, and satellite-based estimates of watershed evapotranspiration (ET) and gross primary productivity (GPP) for 170 National Forest and Grassland (NFs). Across the 72 USGS watersheds, the WaSSI model generally captured the spatial variability of multi-year mean annual and monthly Q and annual ET as evaluated by Correlation Coefficient (R = 0.71–1.0), Nash–Sutcliffe Efficiency (NS = 0.31–1.00), and normalized Root Mean Squared Error (0.06–0.48). The modeled ET and GPP by WaSSI agreed well with the remote sensing-based estimates for multi-year annual and monthly means for all the NFs. However, there were systemic discrepancies in GPP between our simulations and the satellite-based estimates on a yearly and monthly scale, suggesting uncertainties in GPP estimates in all methods (i.e., remote sensing and modeling). Overall, our assessments suggested that the WaSSI model had the capability to reconstruct the long-term forest watershed water and carbon balances at a broad scale. This model evaluation study provides a foundation for model applications in understanding the impacts of climate change and variability (e.g., droughts) on NFs ecosystem service functions. Published by Elsevier B.V.
Shanlei Sun - One of the best experts on this subject based on the ideXlab platform.
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divergence of ecosystem services in u s National Forests and grasslands under a changing climate
Scientific Reports, 2016Co-Authors: Kai Duan, Steven G Mcnulty, Ge Sun, Shanlei Sun, Peter V Caldwell, Erika Cohen, Heather Dinon Aldridge, Yang ZhangAbstract:The 170 National Forests and Grasslands (NFs) in the conterminous United States are public lands that provide important ecosystem services such as clean water and timber supply to the American people. This study investigates the potential impacts of climate change on two key ecosystem functions (i.e., water yield and ecosystem productivity) using the most recent climate projections derived from 20 Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that future climate change may result in a significant reduction in water yield but an increase in ecosystem productivity in NFs. On average, gross ecosystem productivity is projected to increase by 76 ~ 229 g C m−2 yr−1 (8% ~ 24%) while water yield is projected to decrease by 18 ~ 31 mm yr−1 (4% ~ 7%) by 2100 as a result of the combination of increased air temperature (+1.8 ~ +5.2 °C) and precipitation (+17 ~ +51 mm yr−1). The notable divergence in ecosystem services of water supply and carbon sequestration is expected to intensify under higher greenhouse gas emission and associated climate change in the future, posing greater challenges to managing NFs for both ecosystem services.
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drought impacts on ecosystem functions of the u s National Forests and grasslands part ii assessment results and management implications
Forest Ecology and Management, 2015Co-Authors: Ge Sun, Shanlei Sun, Peter V Caldwell, Erika Cohen, Steve Mcnulty, Jingfeng Xiao, Yang ZhangAbstract:The 781,000 km 2 (193 million acre) United States National Forests and Grasslands system (NF) provides important ecosystem services such as clean water supply, timber production, wildlife habitat, and recreation opportunities to the American public. Quantifying the historical impacts of climate change and drought on ecosystem functions at the National scale is essential to develop sound forest management and watershed restoration plans under a changing climate. This study applied the previously validated Water Supply and Stress Index model (WaSSI) to 170 NFs in the conterminous U.S. (CONUS) to examine how historical extreme droughts have affected forest water yield (Q) and gross primary productivity (GPP). For each NF, we focused on the five years with the lowest annual SPI3 (Standardized Precipitation Index on a 3-month time scale) during 1962–2012. The extent of extreme droughts as measured by the number of NFs and total area affected by droughts has increased during the last decade. Across all lands in CONUS, the most extreme drought during the past decade occurred in 2002, resulting in a mean reduction of Q by 32% and GPP by 20%. For the 170 individual NFs, on average, the top-five droughts represented a reduction in precipitation by 145 mm yr 1 (or 22%), causing reductions in evap
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drought impacts on ecosystem functions of the u s National Forests and grasslands part i evaluation of a water and carbon balance model
Forest Ecology and Management, 2015Co-Authors: Shanlei Sun, Steven G Mcnulty, Ge Sun, Peter V Caldwell, Erika Cohen, Jingfeng Xiao, Yang ZhangAbstract:Understanding and quantitatively evaluating the regional impacts of climate change and variability (e.g., droughts) on forest ecosystem functions (i.e., water yield, evapotranspiration, and productivity) and services (e.g., fresh water supply and carbon sequestration) is of great importance for developing climate change adaptation strategies for National Forests and Grasslands (NFs) in the United States. However, few reliable continental-scale modeling tools are available to account for both water and carbon dynamics. The objective of this study was to test a monthly water and carbon balance model, the Water Supply Stress Index (WaSSI) model, for potential application in addressing the influences of drought on NFs ecosystem services across the conterminous United States (CONUS). The performance of the WaSSI model was comprehensively assessed with measured streamflow (Q) at 72 U.S. Geological Survey (USGS) gauging stations, and satellite-based estimates of watershed evapotranspiration (ET) and gross primary productivity (GPP) for 170 National Forest and Grassland (NFs). Across the 72 USGS watersheds, the WaSSI model generally captured the spatial variability of multi-year mean annual and monthly Q and annual ET as evaluated by Correlation Coefficient (R = 0.71–1.0), Nash–Sutcliffe Efficiency (NS = 0.31–1.00), and normalized Root Mean Squared Error (0.06–0.48). The modeled ET and GPP by WaSSI agreed well with the remote sensing-based estimates for multi-year annual and monthly means for all the NFs. However, there were systemic discrepancies in GPP between our simulations and the satellite-based estimates on a yearly and monthly scale, suggesting uncertainties in GPP estimates in all methods (i.e., remote sensing and modeling). Overall, our assessments suggested that the WaSSI model had the capability to reconstruct the long-term forest watershed water and carbon balances at a broad scale. This model evaluation study provides a foundation for model applications in understanding the impacts of climate change and variability (e.g., droughts) on NFs ecosystem service functions. Published by Elsevier B.V.
