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• 1. [Article] Long-term Ecological Research in Forest Park: Tracking Urban Impacts to Forest Structure and Productivity

  Current and historic land use practices as well as exposure to an urban environment can impact forest structure and function. Past and ongoing research in Forest Park, a large urban forest in Portland, ...

  Citation × Citation Citation Abstract Copy Title: Long-term Ecological Research in Forest Park: Tracking Urban Impacts to Forest Structure and Productivity Author: Addessi, Andrew, Dresner, Marion Year: 2017 Current and historic land use practices as well as exposure to an urban environment can impact forest structure and function. Past and ongoing research in Forest Park, a large urban forest in Portland, Oregon, suggests that mature Douglas-fir (Psuedotsuga meziesii) dominated conifer stands in the more urban end of the park are not developing certain late successional features. Notably, they lack a shade-tolerant conifer understory composed of western hemlock (Tsuga heterophylla) and western red-cedar (Thuja plicata). Here, I present three lines of investigation taken from several 1-hectare permanent long-term ecological research (LTER) plots in Forest Park. First, I investigated whether plot-level differences in the intensity of past-land use, namely clearcut logging and fire, has created legacy effect on soil health, as measured by soil organic matter, soil pH, and depth of organic horizon. Second, I present 5-year growth and mortality data to characterize productivity patterns in these plots. Last, I analyzed light detection and ranging (LiDAR) data covering Forest Park to determine if canopy structural features diverged across urban and rural sections of the park. Overall, the results indicate some legacy of soil impact to urban areas most effected by past intensive logging. However, forest productivity, mortality, and structural patterns were generally consistent with stand age, and did not show strong patterns related to urban proximity. These results indicate that the lack of shade tolerant species might be most limited by ground level impacts. These results help inform park managers that regeneration of late successional tree species may require active restoration practices that focus on establishing more optimal growing sites. Title: Long-term Ecological Research in Forest Park: Tracking Urban Impacts to Forest Structure and Productivity Author: Addessi, Andrew, Dresner, Marion Year: 2017 Current and historic land use practices as well as exposure to an urban environment can impact forest structure and function. Past and ongoing research in Forest Park, a large urban forest in Portland, Oregon, suggests that mature Douglas-fir (Psuedotsuga meziesii) dominated conifer stands in the more urban end of the park are not developing certain late successional features. Notably, they lack a shade-tolerant conifer understory composed of western hemlock (Tsuga heterophylla) and western red-cedar (Thuja plicata). Here, I present three lines of investigation taken from several 1-hectare permanent long-term ecological research (LTER) plots in Forest Park. First, I investigated whether plot-level differences in the intensity of past-land use, namely clearcut logging and fire, has created legacy effect on soil health, as measured by soil organic matter, soil pH, and depth of organic horizon. Second, I present 5-year growth and mortality data to characterize productivity patterns in these plots. Last, I analyzed light detection and ranging (LiDAR) data covering Forest Park to determine if canopy structural features diverged across urban and rural sections of the park. Overall, the results indicate some legacy of soil impact to urban areas most effected by past intensive logging. However, forest productivity, mortality, and structural patterns were generally consistent with stand age, and did not show strong patterns related to urban proximity. These results indicate that the lack of shade tolerant species might be most limited by ground level impacts. These results help inform park managers that regeneration of late successional tree species may require active restoration practices that focus on establishing more optimal growing sites. Close

• 2. [Article] Community Science and the Ecological Merits of Backyard Habitat Patches and Adjacent Green-Spaces for Urban Avian Species

  In what ways do small-scale urban backyards contribute to local bird abundance and biodiversity? In what ways might these yards serve as an ‘extension’ of neighboring native forest areas? This project ...

  Citation × Citation Citation Abstract Copy Title: Community Science and the Ecological Merits of Backyard Habitat Patches and Adjacent Green-Spaces for Urban Avian Species Author: Gulick, Kristen S., West, Nikkie, Dresner, Marion Year: 2017 In what ways do small-scale urban backyards contribute to local bird abundance and biodiversity? In what ways might these yards serve as an ‘extension’ of neighboring native forest areas? This project investigates the contribution that a group of backyards, certified through the Backyard Habitat Certification Program, have in the suburb of Hillsdale, Oregon, which is adjacent to the natural area of Keller Woodland. Backyard owners functioning as citizen or community scientists assisted with conducting residential bird point-counts once a week in each backyard and the natural area. Counts were done for a total of 8 weeks during nesting season to better understand how backyard habitat restoration might affect their habitat especially when in close proximity to a natural area. The goal of the project was to help better understand the beneficial effects of urban gardening using native plants and diverse vegetation structure as this relates to bird species richness, and to explore the importance of community scientist contributions. Although the sample size was small, no significant trends were found, but the involvement of community scientists indicated increased skill, depth of understanding, and increased motivation for all participating backyard habitat owners. More backyards are needed for future research and extension into lower-income neighborhoods would be very beneficial to increase awareness of urban habitat connectivity and the diversity seen in backyard environmental characteristics and yard owner backyard habitat knowledge. A larger sample size could reveal correlations and provide a greater significance in data findings for bird abundance and diversity. A logical extension of this project would be to investigate food-web effects, specifically avian prey species, and smaller green-spaces that are often present in urban neighborhoods in addition to the large green-spaces. Title: Community Science and the Ecological Merits of Backyard Habitat Patches and Adjacent Green-Spaces for Urban Avian Species Author: Gulick, Kristen S., West, Nikkie, Dresner, Marion Year: 2017 In what ways do small-scale urban backyards contribute to local bird abundance and biodiversity? In what ways might these yards serve as an ‘extension’ of neighboring native forest areas? This project investigates the contribution that a group of backyards, certified through the Backyard Habitat Certification Program, have in the suburb of Hillsdale, Oregon, which is adjacent to the natural area of Keller Woodland. Backyard owners functioning as citizen or community scientists assisted with conducting residential bird point-counts once a week in each backyard and the natural area. Counts were done for a total of 8 weeks during nesting season to better understand how backyard habitat restoration might affect their habitat especially when in close proximity to a natural area. The goal of the project was to help better understand the beneficial effects of urban gardening using native plants and diverse vegetation structure as this relates to bird species richness, and to explore the importance of community scientist contributions. Although the sample size was small, no significant trends were found, but the involvement of community scientists indicated increased skill, depth of understanding, and increased motivation for all participating backyard habitat owners. More backyards are needed for future research and extension into lower-income neighborhoods would be very beneficial to increase awareness of urban habitat connectivity and the diversity seen in backyard environmental characteristics and yard owner backyard habitat knowledge. A larger sample size could reveal correlations and provide a greater significance in data findings for bird abundance and diversity. A logical extension of this project would be to investigate food-web effects, specifically avian prey species, and smaller green-spaces that are often present in urban neighborhoods in addition to the large green-spaces. Close