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• 1. [Article] Restoring Surface Fire Stabilizes Forest Carbon Under Extreme Fire Weather in the Sierra Nevada

  Climate change in the western United States has increased the frequency of extreme fire weather events and is projected to increase the area burned by wildfire in the coming decades. This changing fire regime, ...

  Citation × Citation Citation Abstract Copy Title: Restoring Surface Fire Stabilizes Forest Carbon Under Extreme Fire Weather in the Sierra Nevada Author: Krofcheck, Daniel J., Hurteau, Matthew D., Scheller, Robert M., Loudermilk, E. Louise Year: 2017 Climate change in the western United States has increased the frequency of extreme fire weather events and is projected to increase the area burned by wildfire in the coming decades. This changing fire regime, coupled with increased high-severity fire risk from a legacy of fire exclusion, could destabilize forest carbon (C), decrease net ecosystem exchange (NEE), and consequently reduce the ability of forests to regulate climate through C sequestration. While management options for minimizing the risk of high-severity fire exist, little is known about the longer-term carbon consequences of these actions in the context of continued extreme fire weather events. Our goal was to compare the impacts of extreme wildfire events on carbon stocks and fluxes in a watershed in the Sierra National Forest. We ran simulations to model wildfire under contemporary and extreme fire weather conditions, and test how three management scenarios (no-management, thin-only, thin and maintenance burning) influence fire severity, forest C stocks and fluxes, and wildfire C emissions. We found that the effects of treatment on wildfire under contemporary fire weather were minimal, and management conferred neither significant reduction in fire severity nor increases in C stocks. However, under extreme fire weather, the thin and maintenance burning scenario decreased mean fire severity by 25%, showed significantly greater C stability, and unlike the no-management and thin-only management options, the thin and maintenance burning scenario showed no decrease in NEE relative to the contemporary fire weather scenarios. Further, under extreme fire weather conditions, wildfire C emissions were lowest in the thin and maintenance burning scenario, (reduction of 13.7 Mg C/ha over the simulation period) even when taking into account the C costs associated with prescribed burning. Including prescribed burning in thinning operations may be critical to maintaining C stocks and reducing C emissions in the future where extreme fire weather events are more frequent. Title: Restoring Surface Fire Stabilizes Forest Carbon Under Extreme Fire Weather in the Sierra Nevada Author: Krofcheck, Daniel J., Hurteau, Matthew D., Scheller, Robert M., Loudermilk, E. Louise Year: 2017 Climate change in the western United States has increased the frequency of extreme fire weather events and is projected to increase the area burned by wildfire in the coming decades. This changing fire regime, coupled with increased high-severity fire risk from a legacy of fire exclusion, could destabilize forest carbon (C), decrease net ecosystem exchange (NEE), and consequently reduce the ability of forests to regulate climate through C sequestration. While management options for minimizing the risk of high-severity fire exist, little is known about the longer-term carbon consequences of these actions in the context of continued extreme fire weather events. Our goal was to compare the impacts of extreme wildfire events on carbon stocks and fluxes in a watershed in the Sierra National Forest. We ran simulations to model wildfire under contemporary and extreme fire weather conditions, and test how three management scenarios (no-management, thin-only, thin and maintenance burning) influence fire severity, forest C stocks and fluxes, and wildfire C emissions. We found that the effects of treatment on wildfire under contemporary fire weather were minimal, and management conferred neither significant reduction in fire severity nor increases in C stocks. However, under extreme fire weather, the thin and maintenance burning scenario decreased mean fire severity by 25%, showed significantly greater C stability, and unlike the no-management and thin-only management options, the thin and maintenance burning scenario showed no decrease in NEE relative to the contemporary fire weather scenarios. Further, under extreme fire weather conditions, wildfire C emissions were lowest in the thin and maintenance burning scenario, (reduction of 13.7 Mg C/ha over the simulation period) even when taking into account the C costs associated with prescribed burning. Including prescribed burning in thinning operations may be critical to maintaining C stocks and reducing C emissions in the future where extreme fire weather events are more frequent. Close

• 2. [Article] Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management

  The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented ...

  Citation × Citation Citation Abstract Copy Title: Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management Author: Scheller, Robert M., Van Tuyl, Steve, Clark, Kenneth L., Hom, John, La Puma, Inga Year: 2011 The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented and subject to frequent disturbance and forest management. Over long time periods (>50 years), the balance between oak and pine dominance is determined by fire frequency. As a consequence, the ability of the NJPB to sequester carbon may be contingent upon management activities as well as patterns of historic land use. We simulated 100 years of carbon change using three scenarios: (1) contemporary management as reflected in the recent (1991–2006) fire records, (2) an increase in the fire ignitions within the wildland urban interface areas of the NJPB reflecting increased prescribed fires, and (3) a longer response time to wildfires, reflecting a more liberal burning policy by the New Jersey Forest Fire Service. We used the LANDIS-II model coupled with CENTURY and the Dynamic Fire and Dynamic Biomass Fuels extensions to estimate forest carbon sequestration based on these three scenarios. Calibration and validation via comparison to monthly flux tower data indicated that the model reasonably captured the timing and magnitude of net ecosystem exchange in the absence of Gypsy moth defoliation (r2 = 0.89). Under all scenarios, our simulations suggest that forests of the NJPB will continue to accumulate carbon over the next 100 years under current climatic conditions. Although above ground net primary productivity, live carbon, and detrital carbon were roughly constant or increased only modestly, soil organic carbon continued to increase through time for all forest types except the highly xeric pine plains. Our simulated changes in management reflected only minor alterations to the fire regime and thus management may have only minor effects on total forest carbon budgets in the immediate future particularly when compared to recovery from historic disturbance patterns. Title: Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management Author: Scheller, Robert M., Van Tuyl, Steve, Clark, Kenneth L., Hom, John, La Puma, Inga Year: 2011 The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented and subject to frequent disturbance and forest management. Over long time periods (>50 years), the balance between oak and pine dominance is determined by fire frequency. As a consequence, the ability of the NJPB to sequester carbon may be contingent upon management activities as well as patterns of historic land use. We simulated 100 years of carbon change using three scenarios: (1) contemporary management as reflected in the recent (1991–2006) fire records, (2) an increase in the fire ignitions within the wildland urban interface areas of the NJPB reflecting increased prescribed fires, and (3) a longer response time to wildfires, reflecting a more liberal burning policy by the New Jersey Forest Fire Service. We used the LANDIS-II model coupled with CENTURY and the Dynamic Fire and Dynamic Biomass Fuels extensions to estimate forest carbon sequestration based on these three scenarios. Calibration and validation via comparison to monthly flux tower data indicated that the model reasonably captured the timing and magnitude of net ecosystem exchange in the absence of Gypsy moth defoliation (r2 = 0.89). Under all scenarios, our simulations suggest that forests of the NJPB will continue to accumulate carbon over the next 100 years under current climatic conditions. Although above ground net primary productivity, live carbon, and detrital carbon were roughly constant or increased only modestly, soil organic carbon continued to increase through time for all forest types except the highly xeric pine plains. Our simulated changes in management reflected only minor alterations to the fire regime and thus management may have only minor effects on total forest carbon budgets in the immediate future particularly when compared to recovery from historic disturbance patterns. Close

• 3. [Article] Predicting global change effects on forest biomass and composition in south-central Siberia

  Multiple global changes such as timber harvesting in areas not previously disturbed by cutting and climate change will undoubtedly affect the composition and spatial distribution of boreal forests, which ...

  Citation × Citation Citation Abstract Copy Title: Predicting global change effects on forest biomass and composition in south-central Siberia Author: Gustafson, Eric J., Shvidenko, Anatoly Z., Sturtevant, Brian R., Scheller, Robert M. Year: 2010 Multiple global changes such as timber harvesting in areas not previously disturbed by cutting and climate change will undoubtedly affect the composition and spatial distribution of boreal forests, which will, in turn, affect the ability of these forests to retain carbon and maintain biodiversity. To predict future states of the boreal forest reliably, it is necessary to understand the complex interactions among forest regenerative processes (succession), natural disturbances (e.g., fire, wind, and insects), and anthropogenic disturbances (e.g., timber harvest). We used a landscape succession and disturbance model (LANDIS-II) to study the relative effects of climate change, timber harvesting, and insect outbreaks on forest composition, biomass (carbon), and landscape pattern in south-central Siberia. We found that most response variables were more strongly influenced by timber harvest and insect outbreaks than by the direct effects of climate change. Direct climate effects generally increased tree productivity and modified probability of establishment, but indirect effects on the fire regime generally counteracted the direct effects of climate on forest composition. Harvest and insects significantly changed forest composition, reduced living aboveground biomass, and increased forest fragmentation. We concluded that: (1) Global change is likely to significantly change forest composition of south-central Siberian landscapes, with some changes taking ecosystems outside the historic range of variability. (2) The direct effects of climate change in the study area are not as significant as the exploitation of virgin forest by timber harvest and the potential increased outbreaks of the Siberian silk moth. (3) Novel disturbance by timber harvest and insect outbreaks may greatly reduce the aboveground living biomass of Siberian forests and may significantly alter ecosystem dynamics and wildlife populations by increasing forest fragmentation. Title: Predicting global change effects on forest biomass and composition in south-central Siberia Author: Gustafson, Eric J., Shvidenko, Anatoly Z., Sturtevant, Brian R., Scheller, Robert M. Year: 2010 Multiple global changes such as timber harvesting in areas not previously disturbed by cutting and climate change will undoubtedly affect the composition and spatial distribution of boreal forests, which will, in turn, affect the ability of these forests to retain carbon and maintain biodiversity. To predict future states of the boreal forest reliably, it is necessary to understand the complex interactions among forest regenerative processes (succession), natural disturbances (e.g., fire, wind, and insects), and anthropogenic disturbances (e.g., timber harvest). We used a landscape succession and disturbance model (LANDIS-II) to study the relative effects of climate change, timber harvesting, and insect outbreaks on forest composition, biomass (carbon), and landscape pattern in south-central Siberia. We found that most response variables were more strongly influenced by timber harvest and insect outbreaks than by the direct effects of climate change. Direct climate effects generally increased tree productivity and modified probability of establishment, but indirect effects on the fire regime generally counteracted the direct effects of climate on forest composition. Harvest and insects significantly changed forest composition, reduced living aboveground biomass, and increased forest fragmentation. We concluded that: (1) Global change is likely to significantly change forest composition of south-central Siberian landscapes, with some changes taking ecosystems outside the historic range of variability. (2) The direct effects of climate change in the study area are not as significant as the exploitation of virgin forest by timber harvest and the potential increased outbreaks of the Siberian silk moth. (3) Novel disturbance by timber harvest and insect outbreaks may greatly reduce the aboveground living biomass of Siberian forests and may significantly alter ecosystem dynamics and wildlife populations by increasing forest fragmentation. Close

• 4. [Article] Forest Management Scenarios in a Changing Climate: Trade-Offs Between Carbon, Timber, and Old Forest

  Balancing economic, ecological, and social values has long been a challenge in the forests of the Pacific Northwest, where conflict over timber harvest and old-growth habitat on public lands has been contentious ...

  Citation × Citation Citation Abstract Copy Title: Forest Management Scenarios in a Changing Climate: Trade-Offs Between Carbon, Timber, and Old Forest Author: Scheller, Robert M., Creutzburg, Megan K., Lucash, Melissa S., LeDuc, Stephen D., Johnson, Mark G. Year: 2017 Balancing economic, ecological, and social values has long been a challenge in the forests of the Pacific Northwest, where conflict over timber harvest and old-growth habitat on public lands has been contentious for the past several decades. The Northwest Forest Plan, adopted two decades ago to guide management on federal lands, is currently being revised as the region searches for a balance between sustainable timber yields and habitat for sensitive species. In addition, climate change imposes a high degree of uncertainty on future forest productivity, sustainability of timber harvest, wildfire risk, and species habitat. We evaluated the long-term, landscape-scale trade-offs among carbon (C) storage, timber yield, and old forest habitat given projected climate change and shifts in forest management policy across 2.1 million hectares of forests in the Oregon Coast Range. Projections highlight the divergence between private and public lands under business-as-usual forest management, where private industrial forests are heavily harvested and many public (especially federal) lands increase C and old forest over time but provide little timber. Three alternative management scenarios altering the amount and type of timber harvest show widely varying levels of ecosystem C and old-forest habitat. On federal lands, ecological forestry practices also allowed a simultaneous increase in old forest and natural early-seral habitat. The ecosystem C implications of shifts away from current practices were large, with current practices retaining up to 105 Tg more C than the alternative scenarios by the end of the century. Our results suggest climate change is likely to increase forest productivity by 30–41% and total ecosystem C storage by 11–15% over the next century as warmer winter temperatures allow greater forest productivity in cooler months. These gains in C storage are unlikely to be offset by wildfire under climate change, due to the legacy of management and effective fire suppression. Our scenarios of future conditions can inform policy makers, land managers, and the public about the potential effects of land management alternatives, climate change, and the trade-offs that are inherent to management and policy in the region. Title: Forest Management Scenarios in a Changing Climate: Trade-Offs Between Carbon, Timber, and Old Forest Author: Scheller, Robert M., Creutzburg, Megan K., Lucash, Melissa S., LeDuc, Stephen D., Johnson, Mark G. Year: 2017 Balancing economic, ecological, and social values has long been a challenge in the forests of the Pacific Northwest, where conflict over timber harvest and old-growth habitat on public lands has been contentious for the past several decades. The Northwest Forest Plan, adopted two decades ago to guide management on federal lands, is currently being revised as the region searches for a balance between sustainable timber yields and habitat for sensitive species. In addition, climate change imposes a high degree of uncertainty on future forest productivity, sustainability of timber harvest, wildfire risk, and species habitat. We evaluated the long-term, landscape-scale trade-offs among carbon (C) storage, timber yield, and old forest habitat given projected climate change and shifts in forest management policy across 2.1 million hectares of forests in the Oregon Coast Range. Projections highlight the divergence between private and public lands under business-as-usual forest management, where private industrial forests are heavily harvested and many public (especially federal) lands increase C and old forest over time but provide little timber. Three alternative management scenarios altering the amount and type of timber harvest show widely varying levels of ecosystem C and old-forest habitat. On federal lands, ecological forestry practices also allowed a simultaneous increase in old forest and natural early-seral habitat. The ecosystem C implications of shifts away from current practices were large, with current practices retaining up to 105 Tg more C than the alternative scenarios by the end of the century. Our results suggest climate change is likely to increase forest productivity by 30–41% and total ecosystem C storage by 11–15% over the next century as warmer winter temperatures allow greater forest productivity in cooler months. These gains in C storage are unlikely to be offset by wildfire under climate change, due to the legacy of management and effective fire suppression. Our scenarios of future conditions can inform policy makers, land managers, and the public about the potential effects of land management alternatives, climate change, and the trade-offs that are inherent to management and policy in the region. Close

• 5. [Article] Carbon Sequestration in Managed Temperate Coniferous Forests Under Climate Change

  Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need ...

  Citation × Citation Citation Abstract Copy Title: Carbon Sequestration in Managed Temperate Coniferous Forests Under Climate Change Author: Dymond, Caren C., Beukema, Sarah, Nitschke, Craig R., Coates, K. David, Scheller, Robert M. Year: 2016 Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper–Pine Creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the net sector productivity, a carbon accounting metric that integrates aboveground and belowground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions, and this indicates that both of these components need to be taken into account when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator, net sector productivity, promises to be useful in assessing management effectiveness and mitigation activities. Title: Carbon Sequestration in Managed Temperate Coniferous Forests Under Climate Change Author: Dymond, Caren C., Beukema, Sarah, Nitschke, Craig R., Coates, K. David, Scheller, Robert M. Year: 2016 Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper–Pine Creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the net sector productivity, a carbon accounting metric that integrates aboveground and belowground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions, and this indicates that both of these components need to be taken into account when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator, net sector productivity, promises to be useful in assessing management effectiveness and mitigation activities. Close