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• 1. [Article] Coniferous Forest Biome : summary of research and synthesis activities July 1975-August 1976

  Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are ...

  Citation × Citation Citation Abstract Copy Title: Coniferous Forest Biome : summary of research and synthesis activities July 1975-August 1976 Author: U.S. International Biological Program. Coniferous Forest Biome, University of Washington, Edmonds, Robert L. Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has three components (behavior and Strategies of Individual Ecosystems, Environment and Plant Succession and the Land-Use Model); Analysis of Watersheds, which has two components (Watershed 10 and Findley Lake); and Analysis of aquatic ecosystems, which is divided into two components (Lakes and Streams). A total list of Biome publications is included in the Appendix. A more specific list of open literature publications is available from the Biome Office. Progress of the synthesis activities is discussed in Section 5. Title: Coniferous Forest Biome : summary of research and synthesis activities July 1975-August 1976 Author: U.S. International Biological Program. Coniferous Forest Biome, University of Washington, Edmonds, Robert L. Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has three components (behavior and Strategies of Individual Ecosystems, Environment and Plant Succession and the Land-Use Model); Analysis of Watersheds, which has two components (Watershed 10 and Findley Lake); and Analysis of aquatic ecosystems, which is divided into two components (Lakes and Streams). A total list of Biome publications is included in the Appendix. A more specific list of open literature publications is available from the Biome Office. Progress of the synthesis activities is discussed in Section 5. Close

• 2. [Article] Coniferous Forest Biome : progress report, July 1974 - August 1975

  The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation ...

  Citation × Citation Citation Abstract Copy Title: Coniferous Forest Biome : progress report, July 1974 - August 1975 Author: Edmonds, Robert L., U.S. International Biological Program. Coniferous Forest Biome, University of Washington The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation models that describe nutrient, carbon, and waterflows on a short-term basis (fewer than ten years) and which integrate research results and increase our understanding of coniferous forests and associated aquatic ecosystems. These models are being developed at the process, forest stand or water column, and watershed levels. (3) To develop conceptual and computer simulation models that describe the long-term behavior of coniferous forest ecosystems involving succession and erosion. (4) To understand the linkages between terrestrial and aquatic ecosystems. (5) To determine the effect of manipulations, such as clearcutting, fertilization, and defoliation on terrestrial and aquatic ecosystems. Title: Coniferous Forest Biome : progress report, July 1974 - August 1975 Author: Edmonds, Robert L., U.S. International Biological Program. Coniferous Forest Biome, University of Washington The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation models that describe nutrient, carbon, and waterflows on a short-term basis (fewer than ten years) and which integrate research results and increase our understanding of coniferous forests and associated aquatic ecosystems. These models are being developed at the process, forest stand or water column, and watershed levels. (3) To develop conceptual and computer simulation models that describe the long-term behavior of coniferous forest ecosystems involving succession and erosion. (4) To understand the linkages between terrestrial and aquatic ecosystems. (5) To determine the effect of manipulations, such as clearcutting, fertilization, and defoliation on terrestrial and aquatic ecosystems. Close

• 3. [Article] Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon

  This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in ...

  Citation × Citation Citation Abstract Copy Title: Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon Author: Brown, Eugene Allen This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in the coastal forests of western Oregon is of primary importance to those concerned with the management of this resource. From the more theoretical point of view, there are many unique features associated with this type of vegetation of special interest to the ecologist. Published accounts of studies in Oregon and Washington have been of a generalized nature. None have approached a localized area with the degree of intensity attempted in this study. Due to its close proximity to Oregon State University and the cutting and burning history of the area, the Mary's Peak Watershed has been especially suitable for this study. Mary's Peak is the highest point of the Oregon Coast range having an elevation of 4,097 feet. The Corvallis watershed is located on the eastern slope of the peak and includes both the Rock Creek and Griffith Creek drainages. The area is about five miles long east and west by four miles north and south. The area is managed as a unit by the United States Forest Service. Due to the marine influence, the area has a humid climate averaging approximately 65 inches of precipitation annually with an annual mean temperature of approximately 52°F. Soils are basaltic in origin and are primarily clay loam in texture. In 1950, an epidemic of Douglas fir bark beetles made necessary a program of development which included cutting of dead and infected trees and establishing a road system. Cutting was restricted to small clear cuts. The vegetation in the study area is a Douglas fir-vine maple association. Gaultheria shallon and Berberis nervosa dominate the forest floor with traces of Castanopsis, Corylus, and Cornus. Study plots were located on nine clear cut and burned areas ranging in elevation from 1,300 to 2,800 feet and including north, south, and east exposures. Nineteen study plots, which were 100 x 100 feet, were established in uniform vegetative areas. Plots were also established in the undisturbed areas adjacent to the clear cuts for comparative purposes. Vegetative sampling was done using a device called an ocular point frame which provided a reliable indication of vegetative cover. Sampling was done in both the spring and fall on the second, third, fourth, and fifth years following burning. The stable undisturbed vegetation was sampled only once. Results of the five-year study showed a general increase in total number of plant species. The average total vegetative cover rose abruptly the third, fourth, and fifth years. An analysis indicated that south exposed plots had the greatest vegetative cover the first five years after burning. East plots ranked second and north plots third. By the fourth year, average cover values on clear cut areas exceeded the cover values of understory vegetation on the adjacent uncut forest. Analysis of data regarding seasonal variation indicated sharp decreases in total cover from spring to fall during the first three years. Increasing amounts of perennial vegetation during the fourth and fifth years reduced this seasonal variation markedly. In terms of mean cover trends, the annual herb, Senecio sylvaticus, dominated the second year; Lotus stipularis and Circium vulgare, the third; Lotus and Holcus lanatus , the fourth and fifth. All plant species indicated a wide range of cover values on the plots sampled. Some consistent trends in the sequence of cover dominance are noted. Title: Early stages in plant succession on Douglas fir clearcuts on the Mary's Peak watershed near Corvallis, Oregon Author: Brown, Eugene Allen This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in the coastal forests of western Oregon is of primary importance to those concerned with the management of this resource. From the more theoretical point of view, there are many unique features associated with this type of vegetation of special interest to the ecologist. Published accounts of studies in Oregon and Washington have been of a generalized nature. None have approached a localized area with the degree of intensity attempted in this study. Due to its close proximity to Oregon State University and the cutting and burning history of the area, the Mary's Peak Watershed has been especially suitable for this study. Mary's Peak is the highest point of the Oregon Coast range having an elevation of 4,097 feet. The Corvallis watershed is located on the eastern slope of the peak and includes both the Rock Creek and Griffith Creek drainages. The area is about five miles long east and west by four miles north and south. The area is managed as a unit by the United States Forest Service. Due to the marine influence, the area has a humid climate averaging approximately 65 inches of precipitation annually with an annual mean temperature of approximately 52°F. Soils are basaltic in origin and are primarily clay loam in texture. In 1950, an epidemic of Douglas fir bark beetles made necessary a program of development which included cutting of dead and infected trees and establishing a road system. Cutting was restricted to small clear cuts. The vegetation in the study area is a Douglas fir-vine maple association. Gaultheria shallon and Berberis nervosa dominate the forest floor with traces of Castanopsis, Corylus, and Cornus. Study plots were located on nine clear cut and burned areas ranging in elevation from 1,300 to 2,800 feet and including north, south, and east exposures. Nineteen study plots, which were 100 x 100 feet, were established in uniform vegetative areas. Plots were also established in the undisturbed areas adjacent to the clear cuts for comparative purposes. Vegetative sampling was done using a device called an ocular point frame which provided a reliable indication of vegetative cover. Sampling was done in both the spring and fall on the second, third, fourth, and fifth years following burning. The stable undisturbed vegetation was sampled only once. Results of the five-year study showed a general increase in total number of plant species. The average total vegetative cover rose abruptly the third, fourth, and fifth years. An analysis indicated that south exposed plots had the greatest vegetative cover the first five years after burning. East plots ranked second and north plots third. By the fourth year, average cover values on clear cut areas exceeded the cover values of understory vegetation on the adjacent uncut forest. Analysis of data regarding seasonal variation indicated sharp decreases in total cover from spring to fall during the first three years. Increasing amounts of perennial vegetation during the fourth and fifth years reduced this seasonal variation markedly. In terms of mean cover trends, the annual herb, Senecio sylvaticus, dominated the second year; Lotus stipularis and Circium vulgare, the third; Lotus and Holcus lanatus , the fourth and fifth. All plant species indicated a wide range of cover values on the plots sampled. Some consistent trends in the sequence of cover dominance are noted. Close

• 4. [Article] The phytosociology of some vine maple communities in the Marys Peak watershed

  A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer ...

  Citation × Citation Citation Abstract Copy Title: The phytosociology of some vine maple communities in the Marys Peak watershed Author: Anderson, Howard George A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer circinatum that account for its distribution within these communities were determined. The following plant communities are described: Corylus californica/Bromus vulgaris (CB) Acer circinatum/Gaultheria shallon Corylus californica - Holodiscus discolor (AGs) subtype Tsuga heterophylla/Xerophyllum tenax (AGx) subtype Holodiscus discolor/Gaultheria shallon (HG) Acer circinatum/Polystichum munitum (AP) Oxalis oregana (O) The CB community is confined to south aspects below 1,400 feet along Rock Creek. Pseudotsuga menziesii, Corylus californica and Bromus vulgaris are the usual dominant species in each of the tree, shrub and herb layer respectively. The AGs is found below 1,800 feet, Pseudotsuga, Acer circinatum and Gaultheria shallon are the dominants in each layer. The AGx is a higher elevation counterpart of the AGs found between 1,800 and 3,200 feet. It has similar dominant species to the AGs but species composition is different. The presence of Taxus brevifolia, Tsuga heterophylla and Xerophyllum tenax distinguish this from the AGs. The HG is essentially confined to south slopes between 1,000 and 1,800 feet. Pseudotsuga, Holodiscus discolor and Gaultheria are the dominants. The AP community is restricted to steep north slopes where downslope movement of seepage water occurs. Layer dominants include Tsuga and/or Thuja plicata, Acer circinatum and Polystichum munitum. The O community occurs above 2,500 feet on the north slope of Marys Peak. Species dominants in the old- growth forest include Tsuga and Oxalis oregana. The shrub layer is represented by occasional Tsuga. Differences in response of Acer circinatum to environmental factors are noted between communities. Height, stem diameter, density, canopy coverage, growth form and bryophyte coverage of Rock and Griffith Creeks. The steep slope and the time factor have been effective barriers to the upslope encroachment of vine maple. In the O community vine maple is confined to restricted niches where light is not limiting but it can never become extensively established in the adjacent forest because of the insufficient light intensity and the slowness of spread of the species. This latter feature is an important limitation since the spread of vine maple is quickly arrested during the relatively short time interval between a catastrophic removal of the overstory and re-establishment of the coniferous species. Title: The phytosociology of some vine maple communities in the Marys Peak watershed Author: Anderson, Howard George A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer circinatum that account for its distribution within these communities were determined. The following plant communities are described: Corylus californica/Bromus vulgaris (CB) Acer circinatum/Gaultheria shallon Corylus californica - Holodiscus discolor (AGs) subtype Tsuga heterophylla/Xerophyllum tenax (AGx) subtype Holodiscus discolor/Gaultheria shallon (HG) Acer circinatum/Polystichum munitum (AP) Oxalis oregana (O) The CB community is confined to south aspects below 1,400 feet along Rock Creek. Pseudotsuga menziesii, Corylus californica and Bromus vulgaris are the usual dominant species in each of the tree, shrub and herb layer respectively. The AGs is found below 1,800 feet, Pseudotsuga, Acer circinatum and Gaultheria shallon are the dominants in each layer. The AGx is a higher elevation counterpart of the AGs found between 1,800 and 3,200 feet. It has similar dominant species to the AGs but species composition is different. The presence of Taxus brevifolia, Tsuga heterophylla and Xerophyllum tenax distinguish this from the AGs. The HG is essentially confined to south slopes between 1,000 and 1,800 feet. Pseudotsuga, Holodiscus discolor and Gaultheria are the dominants. The AP community is restricted to steep north slopes where downslope movement of seepage water occurs. Layer dominants include Tsuga and/or Thuja plicata, Acer circinatum and Polystichum munitum. The O community occurs above 2,500 feet on the north slope of Marys Peak. Species dominants in the old- growth forest include Tsuga and Oxalis oregana. The shrub layer is represented by occasional Tsuga. Differences in response of Acer circinatum to environmental factors are noted between communities. Height, stem diameter, density, canopy coverage, growth form and bryophyte coverage of Rock and Griffith Creeks. The steep slope and the time factor have been effective barriers to the upslope encroachment of vine maple. In the O community vine maple is confined to restricted niches where light is not limiting but it can never become extensively established in the adjacent forest because of the insufficient light intensity and the slowness of spread of the species. This latter feature is an important limitation since the spread of vine maple is quickly arrested during the relatively short time interval between a catastrophic removal of the overstory and re-establishment of the coniferous species. Close

• 5. [Article] Long-Term Integrated Studies Show Complex and Surprising Effects of Climate Change in the Northern Hardwood Forest

  Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed ...

  Citation × Citation Citation Abstract Copy Title: Long-Term Integrated Studies Show Complex and Surprising Effects of Climate Change in the Northern Hardwood Forest Author: Groffman, Peter M., Rustad, Lindsay E., Templer, Pamela H., Campbell, John L., Christenson, Lynn M., Lany, Nina K., Socci, Anne M., Vadeboncoeur, Matthew A., Schaberg, Paul G., Wilson, Geoffrey W., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Goodale, Christine L., Green, Mark B., Hamburg, Steven P., Johnson, Chris E., Mitchell, Mryon J., Morse, Jennifer L., Pardo, Linda H., Rodenhouse, Nicholas L. Year: 2012 Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed and natural elevation gradient studies at the Hubbard Brook Experimental Forest and in the surrounding region show surprising results demonstrating the effects of climate change on hydrologic variables (e.g., evapotranspiration, streamflow, soil moisture); the importance of changes in phenology on water, carbon, and nitrogen fluxes during critical seasonal transition periods; winter climate change effects on plant and animal community composition and ecosystem services; and the effects of anthropogenic disturbances and land-use history on plant community composition. These studies highlight the value of long-term integrated research for assessments of the subtle effects of changing climate on complex ecosystems Title: Long-Term Integrated Studies Show Complex and Surprising Effects of Climate Change in the Northern Hardwood Forest Author: Groffman, Peter M., Rustad, Lindsay E., Templer, Pamela H., Campbell, John L., Christenson, Lynn M., Lany, Nina K., Socci, Anne M., Vadeboncoeur, Matthew A., Schaberg, Paul G., Wilson, Geoffrey W., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Goodale, Christine L., Green, Mark B., Hamburg, Steven P., Johnson, Chris E., Mitchell, Mryon J., Morse, Jennifer L., Pardo, Linda H., Rodenhouse, Nicholas L. Year: 2012 Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed and natural elevation gradient studies at the Hubbard Brook Experimental Forest and in the surrounding region show surprising results demonstrating the effects of climate change on hydrologic variables (e.g., evapotranspiration, streamflow, soil moisture); the importance of changes in phenology on water, carbon, and nitrogen fluxes during critical seasonal transition periods; winter climate change effects on plant and animal community composition and ecosystem services; and the effects of anthropogenic disturbances and land-use history on plant community composition. These studies highlight the value of long-term integrated research for assessments of the subtle effects of changing climate on complex ecosystems Close

• 6. [Article] Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin

  Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their ...

  Citation × Citation Citation Abstract Copy Title: Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin Author: Scheller, Robert M., Kretchun, Alec M., Loudermilk, E. Louise, Hurteau, Matthew D., Weisberg, Peter J., Skinner, Carl Year: 2017 Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their long-term interactions with future climate change are poorly understood. Droughts and the associated moisture deficit contribute to the onset of bark beetle outbreaks although outbreak extent and severity is dependent upon the density of host trees, wildfire, and forest management. Our objective was to estimate the effects of climate change and bark beetle outbreaks on ecosystem carbon dynamics over the next century in a western US forest. Specifically, we hypothesized that (a) bark beetle outbreaks under climate change would reduce net ecosystem carbon balance (NECB) and increase uncertainty and (b) these effects could be ameliorated by fuels management. We also examined the specific tree species dynamics—competition and release—that determined NECB response to bark beetle outbreaks. Our study area was the Lake Tahoe Basin (LTB), CA and NV, USA, an area of diverse forest types encompassing steep elevation and climatic gradients and representative of mixed-conifer forests throughout the western United States. We simulated climate change, bark beetles, wildfire, and fuels management using a landscape-scale stochastic model of disturbance and succession. We simulated the period 2010–2100 using downscaled climate projections. Recurring droughts generated conditions conducive to large-scale outbreaks; the resulting large and sustained outbreaks significantly increased the probability of LTB forests becoming C sources over decadal time scales, with slower-than-anticipated landscape-scale recovery. Tree species composition was substantially altered with a reduction in functional redundancy and productivity. Results indicate heightened uncertainty due to the synergistic influences of climate change and interacting disturbances. Our results further indicate that current fuel management practices will not be effective at reducing landscape-scale outbreak mortality. Our results provide critical insights into the interaction of drivers (bark beetles, wildfire, fuel management) that increase the risk of C loss and shifting community composition if bark beetle outbreaks become more frequent. Title: Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin Author: Scheller, Robert M., Kretchun, Alec M., Loudermilk, E. Louise, Hurteau, Matthew D., Weisberg, Peter J., Skinner, Carl Year: 2017 Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their long-term interactions with future climate change are poorly understood. Droughts and the associated moisture deficit contribute to the onset of bark beetle outbreaks although outbreak extent and severity is dependent upon the density of host trees, wildfire, and forest management. Our objective was to estimate the effects of climate change and bark beetle outbreaks on ecosystem carbon dynamics over the next century in a western US forest. Specifically, we hypothesized that (a) bark beetle outbreaks under climate change would reduce net ecosystem carbon balance (NECB) and increase uncertainty and (b) these effects could be ameliorated by fuels management. We also examined the specific tree species dynamics—competition and release—that determined NECB response to bark beetle outbreaks. Our study area was the Lake Tahoe Basin (LTB), CA and NV, USA, an area of diverse forest types encompassing steep elevation and climatic gradients and representative of mixed-conifer forests throughout the western United States. We simulated climate change, bark beetles, wildfire, and fuels management using a landscape-scale stochastic model of disturbance and succession. We simulated the period 2010–2100 using downscaled climate projections. Recurring droughts generated conditions conducive to large-scale outbreaks; the resulting large and sustained outbreaks significantly increased the probability of LTB forests becoming C sources over decadal time scales, with slower-than-anticipated landscape-scale recovery. Tree species composition was substantially altered with a reduction in functional redundancy and productivity. Results indicate heightened uncertainty due to the synergistic influences of climate change and interacting disturbances. Our results further indicate that current fuel management practices will not be effective at reducing landscape-scale outbreak mortality. Our results provide critical insights into the interaction of drivers (bark beetles, wildfire, fuel management) that increase the risk of C loss and shifting community composition if bark beetle outbreaks become more frequent. Close