Towards an integrated approach to urban watershed planning: Linking vegetation patterns, human preferences, and stream biotic conditions in the Puget Sound lowland (Washington)

Since the enactment of the Endangered Species Act of 1973, over 1200 species have been listed as endangered and threatened in the United States, and the number continues to grow. In the Seattle metropolitan region, decades of urban growth have culminated in the federal listing of the Puget Sound Chinook and several other species of salmon. While research on non-urban streams has emphasized the importance of 'best management practices' (BMPs), such as vegetated buffers, urban areas contain physical impediments (i.e. buildings, walkways, etc.) and human activities (i.e. gardening, pruning, re-vegetation, etc.) that often preclude the application of BMPs within the watershed. Additionally, extensive private ownership of streamside parcels requires consideration of human preferences for riparian vegetation in developing management plans in urban areas.; I develop an integrated framework that links vegetation patterns of Puget Sound lowland with human preferences and stream biotic conditions. By focusing on the role of vegetation patterns in maintaining the biotic integrity of stream conditions, I ask two questions: (1) How do vegetation patterns at the riparian and watershed scales help to explain in-stream biological conditions? (2) How can urban planners use information about the human preference for riparian vegetation to develop appropriate riparian management strategies? To address the first question, I use parametric and nonparametric analysis to isolate riparian areas from upland areas, and examine the role of composition and configuration of vegetation on aquatic conditions. I address the second question by conducting a survey of that identifies specific aesthetic and engagement preferences of streamside residents.; The results corroborate previous research findings that the total amount of riparian vegetation is associated with in-stream biotic conditions. The study goes further to suggest that the fragmentation of upland forests (alternatively, the size of upland forest patches) in urban watersheds are significantly correlated to in-stream biological conditions, and that patch size explain part of the variability in these conditions when controlling for the total amount of riparian vegetation. In addition, the survey of streamside residents shows that: (1) visual preference for riparian vegetation is not correlated with the actual amount of riparian vegetation found in privately held parcels; (2) streamside residents trust friends, family, university scientists, and nongovernmental organizations for providing information on property care; and (3) streamside residents lack both understanding of permissible activities along the riparian corridor and sources of information for managing privately held lands. These results help to frame future research by linking riparian to watershed vegetation patterns, and by better integrating humans into the study of urban watersheds.