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• 1. [Article] Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon

  Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, ...

  Citation × Citation Citation Abstract Copy Title: Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon Author: Hood, Paula Elizabeth Year: 2015 Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, use of heavy logging equipment, and alteration of natural hydrologic patterns within the watershed can increase landslide rates, create erosion, and generate fine sediments. Selective logging, also called thinning, is a logging practice that leaves some trees within sale units unharvested. The ecological impacts of thinning on stream ecosystems are not fully understood and need further study. My hypothesis was that macroinvertebrate assemblages would be different in streams in non-reference areas that contain recent selective logging compared to streams in reference areas, and in downstream vs. upstream of selective logging units. I also hypothesized that selective logging and high road densities would be associated with increased instream fine sediments. I sampled water quality parameters and macroinvertebrates in three managed and three reference streams in the Clackamas River Basin during the field season of 2013. Turbidity, temperature, dissolved oxygen, conductivity, total dissolved solids (TDS), suspended sediment concentrations (SSC), and flow were sampled at each stream on four occasions during spring through early fall. Macroinvertebrates were sampled once in late summer or early fall. EPA rapid habitat assessments, canopy cover, pebble counts, embeddedness, and slope were also determined. Water quality parameters and macroinvertebrate indices in reference and non-reference sites were compared using t-tests, Welch's tests, or rank based equivalents. Macroinvertebrate assemblage patterns and associated environmental variables were characterized using non-metric multidimensional scaling (NMDS) ordination plots and envfit overlays. Macroinvertebrates had higher abundance and taxa richness in non-reference streams, and indices suggested poorer water quality in non-reference streams. Non-reference streams had a lower percentage of shredders and a higher portion of gatherer-collectors. Associations between land use, fine sediments, and changes in macroinvertebrate metrics and community assemblages were apparent at the reference vs. non-reference scale. It is likely that macroinvertebrates are responding, at least in part, to past logging and high road densities in non-reference streams. Fewer indications were found that recent logging may be affecting water quality and macroinvertebrates. Pearson's correlation coefficients show that the percent of recent logging upstream of study sites was correlated with several measures of fine sediments, suggesting that recent land use may be affecting sediment levels at the subwatershed scale. Stream temperatures increased from upstream to downstream in non-reference sites. Though no continual stream temperature data were collected in this study, the history of continuing temperature standard exceedances in the area suggest that further investigation of how selective logging may be affecting stream temperature and other water quality parameters in the Clackamas Basin is warranted. No other differences in water quality parameters were found from upstream to downstream, possibly because water quality was sufficiently protected, or because signals from land use impacts may be obscured by a several factors, including upstream confounding factors such as roads and past logging, and natural variability. Title: Effects of Selective Logging and Roads on Instream Fine Sediments and Macroinvertebrate Assemblages in the Clackamas Basin, Oregon Author: Hood, Paula Elizabeth Year: 2015 Logging and associated skid trails, haul routes, and roads can have significant impacts on the magnitude and timing of sediments in streams in forested watersheds. Loss of vegetation, soil compaction, use of heavy logging equipment, and alteration of natural hydrologic patterns within the watershed can increase landslide rates, create erosion, and generate fine sediments. Selective logging, also called thinning, is a logging practice that leaves some trees within sale units unharvested. The ecological impacts of thinning on stream ecosystems are not fully understood and need further study. My hypothesis was that macroinvertebrate assemblages would be different in streams in non-reference areas that contain recent selective logging compared to streams in reference areas, and in downstream vs. upstream of selective logging units. I also hypothesized that selective logging and high road densities would be associated with increased instream fine sediments. I sampled water quality parameters and macroinvertebrates in three managed and three reference streams in the Clackamas River Basin during the field season of 2013. Turbidity, temperature, dissolved oxygen, conductivity, total dissolved solids (TDS), suspended sediment concentrations (SSC), and flow were sampled at each stream on four occasions during spring through early fall. Macroinvertebrates were sampled once in late summer or early fall. EPA rapid habitat assessments, canopy cover, pebble counts, embeddedness, and slope were also determined. Water quality parameters and macroinvertebrate indices in reference and non-reference sites were compared using t-tests, Welch's tests, or rank based equivalents. Macroinvertebrate assemblage patterns and associated environmental variables were characterized using non-metric multidimensional scaling (NMDS) ordination plots and envfit overlays. Macroinvertebrates had higher abundance and taxa richness in non-reference streams, and indices suggested poorer water quality in non-reference streams. Non-reference streams had a lower percentage of shredders and a higher portion of gatherer-collectors. Associations between land use, fine sediments, and changes in macroinvertebrate metrics and community assemblages were apparent at the reference vs. non-reference scale. It is likely that macroinvertebrates are responding, at least in part, to past logging and high road densities in non-reference streams. Fewer indications were found that recent logging may be affecting water quality and macroinvertebrates. Pearson's correlation coefficients show that the percent of recent logging upstream of study sites was correlated with several measures of fine sediments, suggesting that recent land use may be affecting sediment levels at the subwatershed scale. Stream temperatures increased from upstream to downstream in non-reference sites. Though no continual stream temperature data were collected in this study, the history of continuing temperature standard exceedances in the area suggest that further investigation of how selective logging may be affecting stream temperature and other water quality parameters in the Clackamas Basin is warranted. No other differences in water quality parameters were found from upstream to downstream, possibly because water quality was sufficiently protected, or because signals from land use impacts may be obscured by a several factors, including upstream confounding factors such as roads and past logging, and natural variability. Close

• 2. [Article] Urban Impacts to Forest Productivity, Soil Quality, and Canopy Structure in Forest Park, Portland, Oregon

  Land use practices and exposure to low impact disturbances associated with an urban environment can alter forest structure and function. Past and ongoing research in Forest Park, a large urban forest in ...

  Citation × Citation Citation Abstract Copy Title: Urban Impacts to Forest Productivity, Soil Quality, and Canopy Structure in Forest Park, Portland, Oregon Author: Addessi, Andrew David Year: 2017 Land use practices and exposure to low impact disturbances associated with an urban environment can alter forest structure and function. Past and ongoing research in Forest Park, a large urban forest in Portland, Oregon, suggests that mature mixed Douglas-fir (Psuedotsuga meziesii)-hardwood stands in the more urban end of the park lack a shade-tolerant conifer understory composed of the late successional conifer tree species, such western hemlock (Tsuga heterophylla) and western red-cedar (Thuja plicata). 5-year plot remeasurement data that characterizes productivity and mortality patterns did not show a strong relationship to urban proximity. Plot productivity was generally consistent with values taken from studies of other similarly aged (~100 years old) Douglas-fir /Western Hemlock stands. Mortality was highest in rural plots, and was driven by large windthrow events to canopy trees. Soil organic matter, soil pH, and depth of organic horizon indicated a legacy of soil impact in urban areas most impacted by past intensive logging. The urban mature plot had higher mean soil pH at site (5.87, se: ±0.06) compared to a rural mature, and old growth reference sites located within the park. Although surface organic and A layer soil horizon depth was thinnest at the urban mature site, soil organic matter was not found to be significantly different across sites. Light detection and ranging ( LiDAR) data showed that old-growth plots and plots in the middle section of the park had the highest degree of canopy structure as measured by Rumple and standard deviation of point elevation. Measures of stand height showed OG plots and urban plots to have the tallest trees. Rural plots showed a high degree of variability in all LiDAR metrics, showing a wider range of stand height and complexity than urban and middle plots. These results suggest that past land-use and urban proximity affect plot level productivity, soil quality, and above-ground canopy structure in Forest Park. These results clarify how the lack of late-successional tree species might be most linked to differing histories of intensive logging activity within the park. Reduced old-growth legacy features (remnant seed trees, coarse woody debris) in plots with a clear history of aggressive clear-cuts has led to a reduction in regeneration of western hemlock and western red-cedar in the understory. Title: Urban Impacts to Forest Productivity, Soil Quality, and Canopy Structure in Forest Park, Portland, Oregon Author: Addessi, Andrew David Year: 2017 Land use practices and exposure to low impact disturbances associated with an urban environment can alter forest structure and function. Past and ongoing research in Forest Park, a large urban forest in Portland, Oregon, suggests that mature mixed Douglas-fir (Psuedotsuga meziesii)-hardwood stands in the more urban end of the park lack a shade-tolerant conifer understory composed of the late successional conifer tree species, such western hemlock (Tsuga heterophylla) and western red-cedar (Thuja plicata). 5-year plot remeasurement data that characterizes productivity and mortality patterns did not show a strong relationship to urban proximity. Plot productivity was generally consistent with values taken from studies of other similarly aged (~100 years old) Douglas-fir /Western Hemlock stands. Mortality was highest in rural plots, and was driven by large windthrow events to canopy trees. Soil organic matter, soil pH, and depth of organic horizon indicated a legacy of soil impact in urban areas most impacted by past intensive logging. The urban mature plot had higher mean soil pH at site (5.87, se: ±0.06) compared to a rural mature, and old growth reference sites located within the park. Although surface organic and A layer soil horizon depth was thinnest at the urban mature site, soil organic matter was not found to be significantly different across sites. Light detection and ranging ( LiDAR) data showed that old-growth plots and plots in the middle section of the park had the highest degree of canopy structure as measured by Rumple and standard deviation of point elevation. Measures of stand height showed OG plots and urban plots to have the tallest trees. Rural plots showed a high degree of variability in all LiDAR metrics, showing a wider range of stand height and complexity than urban and middle plots. These results suggest that past land-use and urban proximity affect plot level productivity, soil quality, and above-ground canopy structure in Forest Park. These results clarify how the lack of late-successional tree species might be most linked to differing histories of intensive logging activity within the park. Reduced old-growth legacy features (remnant seed trees, coarse woody debris) in plots with a clear history of aggressive clear-cuts has led to a reduction in regeneration of western hemlock and western red-cedar in the understory. Close

• 3. [Article] Southern Annular Mode Drives Multicentury Wildfire Activity in Southern South America

  The Southern Annular Mode (SAM) is the main driver of climate variability at mid to high latitudes in the Southern Hemisphere, affecting wildfire activity, which in turn pollutes the air and contributes ...

  Citation × Citation Citation Abstract Copy Title: Southern Annular Mode Drives Multicentury Wildfire Activity in Southern South America Author: Holz, Andres, Paritsis, Juan, Mundo, Ignacio A., Veblen, Thomas T., Williamson, Grant J., Araoz, Ezequiel, Bustos-Schindler, Carlos, Gonzalez, Mauro E., Grau, H. Ricardo, Quezada, Juan M. Year: 2017 The Southern Annular Mode (SAM) is the main driver of climate variability at mid to high latitudes in the Southern Hemisphere, affecting wildfire activity, which in turn pollutes the air and contributes to human health problems and mortality, and potentially provides strong feedback to the climate system through emissions and land cover changes. Here we report the largest Southern Hemisphere network of annually resolved tree ring fire histories, consisting of 1,767 fire-scarred trees from 97 sites (from 22 °S to 54 °S) in southern South America (SAS), to quantify the coupling of SAM and regional wildfire variability using recently created multicentury proxy indices of SAM for the years 1531–2010 AD. We show that at interannual time scales, as well as at multidecadal time scales across 37–54 °S, latitudinal gradient elevated wildfire activity is synchronous with positive phases of the SAM over the years 1665–1995. Positive phases of the SAM are associated primarily with warm conditions in these biomass-rich forests, in which widespread fire activity depends on fuel desiccation. Climate modeling studies indicate that greenhouse gases will force SAM into its positive phase even if stratospheric ozone returns to normal levels, so that climate conditions conducive to widespread fire activity in SAS will continue throughout the 21st century. Title: Southern Annular Mode Drives Multicentury Wildfire Activity in Southern South America Author: Holz, Andres, Paritsis, Juan, Mundo, Ignacio A., Veblen, Thomas T., Williamson, Grant J., Araoz, Ezequiel, Bustos-Schindler, Carlos, Gonzalez, Mauro E., Grau, H. Ricardo, Quezada, Juan M. Year: 2017 The Southern Annular Mode (SAM) is the main driver of climate variability at mid to high latitudes in the Southern Hemisphere, affecting wildfire activity, which in turn pollutes the air and contributes to human health problems and mortality, and potentially provides strong feedback to the climate system through emissions and land cover changes. Here we report the largest Southern Hemisphere network of annually resolved tree ring fire histories, consisting of 1,767 fire-scarred trees from 97 sites (from 22 °S to 54 °S) in southern South America (SAS), to quantify the coupling of SAM and regional wildfire variability using recently created multicentury proxy indices of SAM for the years 1531–2010 AD. We show that at interannual time scales, as well as at multidecadal time scales across 37–54 °S, latitudinal gradient elevated wildfire activity is synchronous with positive phases of the SAM over the years 1665–1995. Positive phases of the SAM are associated primarily with warm conditions in these biomass-rich forests, in which widespread fire activity depends on fuel desiccation. Climate modeling studies indicate that greenhouse gases will force SAM into its positive phase even if stratospheric ozone returns to normal levels, so that climate conditions conducive to widespread fire activity in SAS will continue throughout the 21st century. Close

• 4. [Article] Investigating the Potential of Land Use Modifications to Mitigate the Respiratory Health Impacts of NO2: A Case Study in the Portland-Vancouver Metropolitan Area

  The health impacts of urban air pollution are a growing concern in our rapidly urbanizing world. Urban air pollutants show high intra-urban spatial variability linked to urban land use and land cover (LULC). ...

  Citation × Citation Citation Abstract Copy Title: Investigating the Potential of Land Use Modifications to Mitigate the Respiratory Health Impacts of NO2: A Case Study in the Portland-Vancouver Metropolitan Area Author: Rao, Meenakshi Year: 2016 The health impacts of urban air pollution are a growing concern in our rapidly urbanizing world. Urban air pollutants show high intra-urban spatial variability linked to urban land use and land cover (LULC). This correlation of air pollutants with LULC is widely recognized; LULC data is an integral input into a wide range of models, especially land use regression models developed by epidemiologists to study the impact of air pollution on human health. Given the demonstrated links between LULC and urban air pollution, and between urban air pollution and health, an interesting question arises: what is the potential of LULC modifications to mitigate the health impacts of urban air pollution? In this dissertation we assess the potential of LULC modifications to mitigate the health impacts of NO2, a respiratory irritant and strong marker for combustion-related air pollution, in the Portland-Vancouver metropolitan area in northwestern USA. We begin by measuring summer and winter NO2 in the area using a spatially dense network of passive NO2 samplers. We next develop an annual average model for NO2 based on the observational data, using random forest -- for the first time in the realm of urban air pollution -- to disentangle the effects of highly correlated LULC variables on ambient NO2 concentrations. We apply this random forest (LURF) model to a 200m spatial grid covering the study area, and use this 200m LURF model to quantify the effect of different urban land use categories on ambient concentrations of NO2. Using the changes in ambient NO2 concentrations resulting from land use modifications as input to BenMAP (a health benefits assessment tool form the US EPA), we assess the NO2-related health impact associated with each land use category and its modifications. We demonstrate how the LURF model can be used to assess the respiratory health benefits of competing land use modifications, including city-wide and local-scale mitigation strategies based on modifying tree canopy and vehicle miles traveled (VMT). Planting trees is a common land cover modification strategy undertaken by cities to reduce air pollution. Statistical models such as LUR and LURF demonstrate a correlation between tree cover and reduced air pollution, but they cannot demonstrate causation. Hence, we run the atmospheric chemistry and transport model CMAQ to examine to what extent the dry deposition mechanism can explain the reduction of NO2 which statistical models associate with tree canopy. Results from our research indicate that even though the Portland-Vancouver area is in compliance with the US EPA NO2 standards, ambient concentrations of NO2 still create an annual health burden of at least $40 million USD. Our model suggests that NO2 associated with high intensity development and VMT may be creating an annual health burden of $7 million and $3.3 million USD respectively. Existing tree canopy, on the other hand, is associated with an annual health benefit of $1.4 million USD. LULC modifications can mitigate some fraction of this health burden. A 2% increase in tree canopy across the study area may reduce incidence rates of asthma exacerbation by as much as 7%. We also find that increasing tree canopy is a more effective strategy than reducing VMT in terms of mitigating the health burden of NO2. CMAQ indicates that the amount of NO2 removed by dry deposition is an order of magnitude smaller than that predicted by our statistical model. About one-third of the difference can be explained by the lower NO2 values predicted by CMAQ, and one-third may be attributable to parameterization of stomatal uptake. Title: Investigating the Potential of Land Use Modifications to Mitigate the Respiratory Health Impacts of NO2: A Case Study in the Portland-Vancouver Metropolitan Area Author: Rao, Meenakshi Year: 2016 The health impacts of urban air pollution are a growing concern in our rapidly urbanizing world. Urban air pollutants show high intra-urban spatial variability linked to urban land use and land cover (LULC). This correlation of air pollutants with LULC is widely recognized; LULC data is an integral input into a wide range of models, especially land use regression models developed by epidemiologists to study the impact of air pollution on human health. Given the demonstrated links between LULC and urban air pollution, and between urban air pollution and health, an interesting question arises: what is the potential of LULC modifications to mitigate the health impacts of urban air pollution? In this dissertation we assess the potential of LULC modifications to mitigate the health impacts of NO2, a respiratory irritant and strong marker for combustion-related air pollution, in the Portland-Vancouver metropolitan area in northwestern USA. We begin by measuring summer and winter NO2 in the area using a spatially dense network of passive NO2 samplers. We next develop an annual average model for NO2 based on the observational data, using random forest -- for the first time in the realm of urban air pollution -- to disentangle the effects of highly correlated LULC variables on ambient NO2 concentrations. We apply this random forest (LURF) model to a 200m spatial grid covering the study area, and use this 200m LURF model to quantify the effect of different urban land use categories on ambient concentrations of NO2. Using the changes in ambient NO2 concentrations resulting from land use modifications as input to BenMAP (a health benefits assessment tool form the US EPA), we assess the NO2-related health impact associated with each land use category and its modifications. We demonstrate how the LURF model can be used to assess the respiratory health benefits of competing land use modifications, including city-wide and local-scale mitigation strategies based on modifying tree canopy and vehicle miles traveled (VMT). Planting trees is a common land cover modification strategy undertaken by cities to reduce air pollution. Statistical models such as LUR and LURF demonstrate a correlation between tree cover and reduced air pollution, but they cannot demonstrate causation. Hence, we run the atmospheric chemistry and transport model CMAQ to examine to what extent the dry deposition mechanism can explain the reduction of NO2 which statistical models associate with tree canopy. Results from our research indicate that even though the Portland-Vancouver area is in compliance with the US EPA NO2 standards, ambient concentrations of NO2 still create an annual health burden of at least $40 million USD. Our model suggests that NO2 associated with high intensity development and VMT may be creating an annual health burden of $7 million and $3.3 million USD respectively. Existing tree canopy, on the other hand, is associated with an annual health benefit of $1.4 million USD. LULC modifications can mitigate some fraction of this health burden. A 2% increase in tree canopy across the study area may reduce incidence rates of asthma exacerbation by as much as 7%. We also find that increasing tree canopy is a more effective strategy than reducing VMT in terms of mitigating the health burden of NO2. CMAQ indicates that the amount of NO2 removed by dry deposition is an order of magnitude smaller than that predicted by our statistical model. About one-third of the difference can be explained by the lower NO2 values predicted by CMAQ, and one-third may be attributable to parameterization of stomatal uptake. Close

• 5. [Article] Ecological Homogenization of Urban USA

  A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential ...

  Citation × Citation Citation Abstract Copy Title: Ecological Homogenization of Urban USA Author: Groffman, Peter M., Cavender-Bares, Jeannine, Bettez, Neil D., Grove, J. Morgan, Hall, Sharon J., Heffernan, James B., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K. Year: 2014 A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial areas, and aquatic features. We hypothesize that this homogenization extends to ecological structure and also to ecosystem functions such as carbon dynamics and microclimate, with continental-scale implications. Further, we suggest that understanding urban homogenization will provide the basis for understanding the impacts of urban land-use change from local to continental scales. Here, we show how multi-scale, multi-disciplinary datasets from six metropolitan areas that cover the major climatic regions of the US (Phoenix, AZ; Miami, FL; Baltimore, MD; Boston, MA; Minneapolis–St Paul, MN; and Los Angeles, CA) can be used to determine how household and neighborhood characteristics correlate with land-management practices, land-cover composition, and landscape structure and ecosystem functions at local, regional, and continental scales. Title: Ecological Homogenization of Urban USA Author: Groffman, Peter M., Cavender-Bares, Jeannine, Bettez, Neil D., Grove, J. Morgan, Hall, Sharon J., Heffernan, James B., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K. Year: 2014 A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial areas, and aquatic features. We hypothesize that this homogenization extends to ecological structure and also to ecosystem functions such as carbon dynamics and microclimate, with continental-scale implications. Further, we suggest that understanding urban homogenization will provide the basis for understanding the impacts of urban land-use change from local to continental scales. Here, we show how multi-scale, multi-disciplinary datasets from six metropolitan areas that cover the major climatic regions of the US (Phoenix, AZ; Miami, FL; Baltimore, MD; Boston, MA; Minneapolis–St Paul, MN; and Los Angeles, CA) can be used to determine how household and neighborhood characteristics correlate with land-management practices, land-cover composition, and landscape structure and ecosystem functions at local, regional, and continental scales. Close

• 6. [Article] Assessing the Potential of Land Use Modification to Mitigate Ambient NO2 and Its Consequences for Respiratory Health

  Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO2 is modeled ...

  Citation × Citation Citation Abstract Copy Title: Assessing the Potential of Land Use Modification to Mitigate Ambient NO2 and Its Consequences for Respiratory Health Author: Rao, Meenakshi, George, Linda A., Shandas, Vivek, Rosenstiel, Todd N. Year: 2017 Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO2 is modeled based on spatially dense summer and winter NO2 observations in Portland-Hillsboro-Vancouver (USA), and the spatial variation of NO2 with LULC investigated using random forest, an ensemble data learning technique. The NO2 random forest model, together with BenMAP, is further used to develop a better understanding of the relationship among LULC, ambient NO2 and respiratory health. The impact of land use modifications on ambient NO2, and consequently on respiratory health, is also investigated using a sensitivity analysis. We find that NO2 associated with roadways and tree-canopied areas may be affecting annual incidence rates of asthma exacerbation in 4–12 year olds by +3000 per 100,000 and -1400 per 100,000, respectively. Our model shows that increasing local tree canopy by 5% may reduce local incidences rates of asthma exacerbation by 6%, indicating that targeted local tree-planting efforts may have a substantial impact on reducing city-wide incidence of respiratory distress. Our findings demonstrate the utility of random forest modeling in evaluating LULC modifications for enhanced respiratory health. Title: Assessing the Potential of Land Use Modification to Mitigate Ambient NO2 and Its Consequences for Respiratory Health Author: Rao, Meenakshi, George, Linda A., Shandas, Vivek, Rosenstiel, Todd N. Year: 2017 Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO2 is modeled based on spatially dense summer and winter NO2 observations in Portland-Hillsboro-Vancouver (USA), and the spatial variation of NO2 with LULC investigated using random forest, an ensemble data learning technique. The NO2 random forest model, together with BenMAP, is further used to develop a better understanding of the relationship among LULC, ambient NO2 and respiratory health. The impact of land use modifications on ambient NO2, and consequently on respiratory health, is also investigated using a sensitivity analysis. We find that NO2 associated with roadways and tree-canopied areas may be affecting annual incidence rates of asthma exacerbation in 4–12 year olds by +3000 per 100,000 and -1400 per 100,000, respectively. Our model shows that increasing local tree canopy by 5% may reduce local incidences rates of asthma exacerbation by 6%, indicating that targeted local tree-planting efforts may have a substantial impact on reducing city-wide incidence of respiratory distress. Our findings demonstrate the utility of random forest modeling in evaluating LULC modifications for enhanced respiratory health. Close

• 7. [Article] Network Analysis of Wildfire Transmission and Implications for Risk Governance

  We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon ...

  Citation × Citation Citation Abstract Copy Title: Network Analysis of Wildfire Transmission and Implications for Risk Governance Author: Ager, Alan A., Evers, Cody, Day, Michelle A., Preisler, Haiganoush K., Barros, Ana M.G., Nielsen-Pincus, Max Year: 2017 We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon US. Wildfire simulation and network analysis were used to quantify the exchange of fire among land tenures and communities and analyze the relative contributions of human versus natural ignitions to wildfire exposure. Among the land tenures examined, the area burned by incoming fires averaged 57% of the total burned area. Community exposure from incoming fires ignited on surrounding land tenures accounted for 67% of the total area burned. The number of land tenures contributing wildfire to individual communities and surrounding wildland urban interface (WUI) varied from 3 to 20. Community firesheds, i.e. the area where ignitions can spawn fires that can burn into the WUI, covered 40% of the landscape, and were 5.5 times larger than the combined area of the community core and WUI. For the major land tenures within the study area, the amount of incoming versus outgoing fire was relatively constant, with some exceptions. The study provides a multi-scale characterization of wildfire networks within a large, mixed tenure and fire prone landscape, and illustrates the connectivity of risk between communities and the surrounding wildlands. We use the findings to discuss how scale mismatches in local wildfire governance result from disconnected planning systems and disparate fire management objectives among the large landowners (federal, state, private) and local communities. Local and regional risk planning processes can adopt our concepts and methods to better define and map the scale of wildfire risk from large fire events and incorporate wildfire network and connectivity concepts into risk assessments. Title: Network Analysis of Wildfire Transmission and Implications for Risk Governance Author: Ager, Alan A., Evers, Cody, Day, Michelle A., Preisler, Haiganoush K., Barros, Ana M.G., Nielsen-Pincus, Max Year: 2017 We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon US. Wildfire simulation and network analysis were used to quantify the exchange of fire among land tenures and communities and analyze the relative contributions of human versus natural ignitions to wildfire exposure. Among the land tenures examined, the area burned by incoming fires averaged 57% of the total burned area. Community exposure from incoming fires ignited on surrounding land tenures accounted for 67% of the total area burned. The number of land tenures contributing wildfire to individual communities and surrounding wildland urban interface (WUI) varied from 3 to 20. Community firesheds, i.e. the area where ignitions can spawn fires that can burn into the WUI, covered 40% of the landscape, and were 5.5 times larger than the combined area of the community core and WUI. For the major land tenures within the study area, the amount of incoming versus outgoing fire was relatively constant, with some exceptions. The study provides a multi-scale characterization of wildfire networks within a large, mixed tenure and fire prone landscape, and illustrates the connectivity of risk between communities and the surrounding wildlands. We use the findings to discuss how scale mismatches in local wildfire governance result from disconnected planning systems and disparate fire management objectives among the large landowners (federal, state, private) and local communities. Local and regional risk planning processes can adopt our concepts and methods to better define and map the scale of wildfire risk from large fire events and incorporate wildfire network and connectivity concepts into risk assessments. Close

• 8. [Article] Watershed Management and Private Lands: Moving Beyond Financial Incentives to Encourage Land Stewardship

  Public water utilities are tasked with providing high quality, inexpensive water often sourced from watersheds representing a diverse mix of public and private land ownership. There is increasing recognition ...

  Citation × Citation Citation Abstract Copy Title: Watershed Management and Private Lands: Moving Beyond Financial Incentives to Encourage Land Stewardship Author: DeAngelo, Matthew Thomas Year: 2016 Public water utilities are tasked with providing high quality, inexpensive water often sourced from watersheds representing a diverse mix of public and private land ownership. There is increasing recognition amongst water resource managers of the role that private landowners play in determining downstream water quality, but bringing together landowners with a wide variety of land management objectives under the umbrella of watershed stewardship has proven difficult. Recently, a large number of "Payment for Watershed Services" programs have aimed to engage private landowners in watershed stewardship initiatives by offering financial incentives for adopting watershed best management practices. However, a growing field of research suggests that financial incentives alone may be of limited utility to encourage widespread and long-standing behavior change, and instead understanding landowner attitudes and non-financial barriers to stewardship program enrollment has become a focus of research. This research examines a population of rural landowners representing a diversity of agricultural, forestry, recreational, and investment objectives in the Clackamas River watershed, Oregon. I designed and distributed a mail and web-based survey instrument intended to measure land uses and land ownership objectives, attitudes towards watershed stewardship programs, barriers to enrollment in stewardship programs, and preferred incentives and goals that would promote enrollment. I received 281 valid responses for a response rate of 29%. I conducted two primary analyses: one focused on relating attitudes and barriers to intent to enroll in a watershed stewardship program, and one focused on identifying how diverse landowners differ according to factors influencing enrollment in stewardship programs. I found that landowners did not report financial considerations to be a primary barrier to enrollment and expressed low interest in receiving financial incentives. Instead, landowners reported that primary barriers related to lack of trust, ecological understanding, and concerns that stewardship program enrollment would be incompatible with their land management objectives. I do not discount the potential utility of financial incentives under certain circumstances, but emphasize the importance of addressing these other considerations before incentives can make a meaningful impact. I compared how barriers to enrollment were perceived by landowners with different land management objectives relating to production, investment, and conservation. I found that landowner attitudes were differentiated from one another primarily by their use of land for production purposes; however, I found a large amount of diversity between producers and non-producers in the degree to which they considered investment and conservation objectives in their land management, and these two variables added further explanatory power to understanding fine-scale differences in how landowner typologies relate to conservation programs. Title: Watershed Management and Private Lands: Moving Beyond Financial Incentives to Encourage Land Stewardship Author: DeAngelo, Matthew Thomas Year: 2016 Public water utilities are tasked with providing high quality, inexpensive water often sourced from watersheds representing a diverse mix of public and private land ownership. There is increasing recognition amongst water resource managers of the role that private landowners play in determining downstream water quality, but bringing together landowners with a wide variety of land management objectives under the umbrella of watershed stewardship has proven difficult. Recently, a large number of "Payment for Watershed Services" programs have aimed to engage private landowners in watershed stewardship initiatives by offering financial incentives for adopting watershed best management practices. However, a growing field of research suggests that financial incentives alone may be of limited utility to encourage widespread and long-standing behavior change, and instead understanding landowner attitudes and non-financial barriers to stewardship program enrollment has become a focus of research. This research examines a population of rural landowners representing a diversity of agricultural, forestry, recreational, and investment objectives in the Clackamas River watershed, Oregon. I designed and distributed a mail and web-based survey instrument intended to measure land uses and land ownership objectives, attitudes towards watershed stewardship programs, barriers to enrollment in stewardship programs, and preferred incentives and goals that would promote enrollment. I received 281 valid responses for a response rate of 29%. I conducted two primary analyses: one focused on relating attitudes and barriers to intent to enroll in a watershed stewardship program, and one focused on identifying how diverse landowners differ according to factors influencing enrollment in stewardship programs. I found that landowners did not report financial considerations to be a primary barrier to enrollment and expressed low interest in receiving financial incentives. Instead, landowners reported that primary barriers related to lack of trust, ecological understanding, and concerns that stewardship program enrollment would be incompatible with their land management objectives. I do not discount the potential utility of financial incentives under certain circumstances, but emphasize the importance of addressing these other considerations before incentives can make a meaningful impact. I compared how barriers to enrollment were perceived by landowners with different land management objectives relating to production, investment, and conservation. I found that landowner attitudes were differentiated from one another primarily by their use of land for production purposes; however, I found a large amount of diversity between producers and non-producers in the degree to which they considered investment and conservation objectives in their land management, and these two variables added further explanatory power to understanding fine-scale differences in how landowner typologies relate to conservation programs. Close

• 9. [Article] How Landscape Ecology Informs Global Land-Change Science and Policy

  Landscape ecology is a discipline that explicitly considers the influence of time and space on the environmental patterns we observe and the processes that create them. Although many of the topics studied ...

  Citation × Citation Citation Abstract Copy Title: How Landscape Ecology Informs Global Land-Change Science and Policy Author: Mayer, Audrey L., Buma, Brian, Davis, Amélie, Gagné, Sara A., Loudermilk, E. Louise, Scheller, Robert M., Schmiegelow, Fiona K.A., Majorin, Fiona, Wiersma, Yolanda F., Franklin, Janet Year: 2016 Landscape ecology is a discipline that explicitly considers the influence of time and space on the environmental patterns we observe and the processes that create them. Although many of the topics studied in landscape ecology have public policy implications, three are of particular concern: climate change; land use–land cover change (LULCC); and a particular type of LULCC, urbanization. These processes are interrelated, because LULCC is driven by both human activities (e.g., agricultural expansion and urban sprawl) and climate change (e.g., desertification). Climate change, in turn, will affect the way humans use landscapes. Interactions among these drivers of ecosystem change can have destabilizing and accelerating feedback, with consequences for human societies from local to global scales. These challenges require landscape ecologists to engage policymakers and practitioners in seeking long-term solutions, informed by an understanding of opportunities to mitigate the impacts of anthropogenic drivers on ecosystems and adapt to new ecological realities. Title: How Landscape Ecology Informs Global Land-Change Science and Policy Author: Mayer, Audrey L., Buma, Brian, Davis, Amélie, Gagné, Sara A., Loudermilk, E. Louise, Scheller, Robert M., Schmiegelow, Fiona K.A., Majorin, Fiona, Wiersma, Yolanda F., Franklin, Janet Year: 2016 Landscape ecology is a discipline that explicitly considers the influence of time and space on the environmental patterns we observe and the processes that create them. Although many of the topics studied in landscape ecology have public policy implications, three are of particular concern: climate change; land use–land cover change (LULCC); and a particular type of LULCC, urbanization. These processes are interrelated, because LULCC is driven by both human activities (e.g., agricultural expansion and urban sprawl) and climate change (e.g., desertification). Climate change, in turn, will affect the way humans use landscapes. Interactions among these drivers of ecosystem change can have destabilizing and accelerating feedback, with consequences for human societies from local to global scales. These challenges require landscape ecologists to engage policymakers and practitioners in seeking long-term solutions, informed by an understanding of opportunities to mitigate the impacts of anthropogenic drivers on ecosystems and adapt to new ecological realities. Close

• 10. [Article] Relationships that Extend Beyond the Fence-Line: Private Landowner Attitudes and Interest in Conservation Easements

  Private land conservation provides an opportunity to address problems of habitat fragmentation and biodiversity loss caused by an increase in the development and parcelization of private land. Conservation ...

  Citation × Citation Citation Abstract Copy Title: Relationships that Extend Beyond the Fence-Line: Private Landowner Attitudes and Interest in Conservation Easements Author: Vizek, Ashley Lyn Year: 2016 Private land conservation provides an opportunity to address problems of habitat fragmentation and biodiversity loss caused by an increase in the development and parcelization of private land. Conservation easements (CEs) are an innovative tool used by land trusts to protect significant natural qualities of private land in perpetuity, while also allowing the land to remain in private ownership. Traditionally, property represents an individualistic relationship, however, CEs redefine this relationship by seeking to maximize the overlap in private and public goods in property. In this study, I explore the relationship between the common good and private property through an analysis of landowner attitudes and interest in conveying CEs. To address my research objectives I implemented a mixed-mode survey to 664 private landowners in the Whychus Creek Watershed in Deschutes County, OR. I received 257 survey responses, yielding a response rate of 41%. The first layer of this study focuses on landowner attitudes towards CEs (Chapter 2). The results of an exploratory factor analysis suggest there are two dimensions to landowner attitudes towards CEs--internal and external dimension. I constructed logistic regression models to predict positive internal and external attitudes and found that external attitudes are primarily influenced by environmental beliefs, whereas internal attitudes are influenced by a suite of factors including financial beliefs and perceived risk to private ownership. Furthermore, landowner knowledge and awareness of CEs may play a role in attitude development. I found that as awareness increased the number of landowners perceiving low risk also increased. Additionally, I found that those who learned about CEs from a peer were more likely to have an extreme positive or negative attitude towards CEs. The second part of this study focuses on landowner interest in conveying a CE (Chapter 3). The results of a multinomial logistic regression analysis suggest that positive external and internal attitudes towards CEs provide the foundation for CE, while personal incentives and connections to the social and/or natural community serve as the motivation driving CE conveyance. Although the results of this study are only representative of landowners in the Whychus Creek Watershed I argue that some of the findings may be more broadly applicable. Contributing to our conceptual understanding of CEs, I discuss how CEs may be beneficial in reintegrating the common good into private property. Further, I highlight that landowner connections to both the social community and natural environment are important characteristics of CE conveyance as well as private land conservation in general. Title: Relationships that Extend Beyond the Fence-Line: Private Landowner Attitudes and Interest in Conservation Easements Author: Vizek, Ashley Lyn Year: 2016 Private land conservation provides an opportunity to address problems of habitat fragmentation and biodiversity loss caused by an increase in the development and parcelization of private land. Conservation easements (CEs) are an innovative tool used by land trusts to protect significant natural qualities of private land in perpetuity, while also allowing the land to remain in private ownership. Traditionally, property represents an individualistic relationship, however, CEs redefine this relationship by seeking to maximize the overlap in private and public goods in property. In this study, I explore the relationship between the common good and private property through an analysis of landowner attitudes and interest in conveying CEs. To address my research objectives I implemented a mixed-mode survey to 664 private landowners in the Whychus Creek Watershed in Deschutes County, OR. I received 257 survey responses, yielding a response rate of 41%. The first layer of this study focuses on landowner attitudes towards CEs (Chapter 2). The results of an exploratory factor analysis suggest there are two dimensions to landowner attitudes towards CEs--internal and external dimension. I constructed logistic regression models to predict positive internal and external attitudes and found that external attitudes are primarily influenced by environmental beliefs, whereas internal attitudes are influenced by a suite of factors including financial beliefs and perceived risk to private ownership. Furthermore, landowner knowledge and awareness of CEs may play a role in attitude development. I found that as awareness increased the number of landowners perceiving low risk also increased. Additionally, I found that those who learned about CEs from a peer were more likely to have an extreme positive or negative attitude towards CEs. The second part of this study focuses on landowner interest in conveying a CE (Chapter 3). The results of a multinomial logistic regression analysis suggest that positive external and internal attitudes towards CEs provide the foundation for CE, while personal incentives and connections to the social and/or natural community serve as the motivation driving CE conveyance. Although the results of this study are only representative of landowners in the Whychus Creek Watershed I argue that some of the findings may be more broadly applicable. Contributing to our conceptual understanding of CEs, I discuss how CEs may be beneficial in reintegrating the common good into private property. Further, I highlight that landowner connections to both the social community and natural environment are important characteristics of CE conveyance as well as private land conservation in general. Close