This book is a first edition technical handbook on a topic that is gaining ever greater attention around the world – urban forestry. Written for international audiences, the book covers a range of conceptual and technical content, including urban forest assessment, planning, and best management practices. Chapters address the full scale of city tree knowledge, from arboricultural activity concerning individual trees to operations across an entire city. Authors were invited to contribute by the editors based on their expertise, so the volume contains the best available science and knowledge about urban forestry. This chapter on social aspects addresses the question of ‘why’ – offering evidence about why urban forests, particularly well managed urban resource systems, are necessary in all urbanized areas. It outlines the social benefits of having high quality trees, stands, and groves in the everyday places of urban living, including public and private properties. Chapter sections address economic values of residential and retail settings, the role of nature in supporting a sense of community and place, social ties, place attachment, issues of crime and safety (including how nature experiences can diminish aggression and violence), attention restoration, environmental equity, cultural expressions of nature, and community resilience. The chapter content was derived from the Green Cities: Good Health web site, a cooperative project of the USDA Forest Service (Research and S&P deputy areas) and University of Washington (Seattle), that is a research synthesis, science delivery product intended for professional and manager audiences.
This is the executive summary of a three-volume science synthesis that addresses various ecological and social concerns regarding management of federal forests encompassed by the Northwest Forest Plan (NWFP). Land managers with the U.S. Forest Service provided questions that helped guide preparation of the synthesis. It builds on the 10-, 15-, and 20-year NWFP monitoring reports and synthesizes the vast body of relevant scientific literature that has accumulated in the 24 years since the NWFP was initiated. Here we summarize scientific findings and considerations for management that were identified in the full science synthesis. We find that the NWFP has protected dense old-growth forests and has maintained habitat for northern spotted owls (Strix occidentalis caurina), marbled murrelets (Brachyramphus marmoratus), aquatic organisms, and other species despite losses from wildfire and low levels of timber harvest on federal lands. Other goals have not been met, including producing a sustainable supply of timber and the broad use of adaptive management. New concerns include the impact of nonnative barred owls (Strix varia) on northern spotted owl populations, effects of fire suppression on forest succession, fire behavior in dry forests, and the effects of climate change and invasive species on native biodiversity. A growing body of scientific evidence supports the importance of active management or restoration inside and outside NWFP reserves to promote a full complement of biodiversity and ecological resilience. Active management to promote heterogeneity of vegetation conditions is important to sustaining tribal ecocultural resources. Declines in agency capacity, lack of markets for small-diameter wood, lack of wood processing infrastructure in some areas, and lack of social agreement have limited the amount of active management for restoration on federal lands. All management choices involve social and ecological tradeoffs related to the goals of the NWFP. Collaboration, risk management, adaptive management, and monitoring are considered elemental approaches in dealing with complex social and ecological systems with futures that are difficult to predict and affect through policy and land management actions.
Past research demonstrating the importance plant–microbe interactions as drivers of ecosystem succession has focused on how plants condition soil microbial communities, impacting subsequent plant performance and plant community assembly. These studies, however, largely treat microbial communities as a black box. In this study, we sought to examine how emblematic shifts from early successional Alnus viridus ssp. sinuata (Sitka alder) to late successional Picea sitchensis (Sitka spruce) in primary succession may be reflected in specific belowground changes in bacterial community structure and nitrogen cycling related to the interaction of these two plants. We examined early successional alder-conditioned soils in a glacial forefield to delineate how alders alter the soil microbial community with increasing dominance. Further, we assessed the impact of late-successional spruce plants on these early successional alder-conditioned microbiomes and related nitrogen cycling through a leachate addition microcosm experiment. We show how increasingly abundant alder select for particular bacterial taxa. Additionally, we found that spruce leachate significantly alters the composition of these microbial communities in large part by driving declines in taxa that are enriched by alder, including bacterial symbionts. We found these effects to be spruce specific, beyond a general leachate effect. Our work also demonstrates a unique influence of spruce on ammonium availability. Such insights bolster theory relating the importance of plant–microbe interactions with late-successional plants and interspecific plant interactions more generally.
The northern spotted owl (Strix occidentalis caurina) was listed as threatened under the Endangered Species Act in 1990 (USFWS 1990). Providing adequate amounts of suitable forest cover to sustain the subspecies was a major component of the first recovery plan for northern spotted owls (USFWS 1992) and a driver in the basic reserve design and old-forest restoration under the Northwest Forest Plan (NWFP, or Plan) (USDA and USDI 1994). The reserve design included large contiguous blocks of late-successional forest, which was expected to be sufficient to provide habitat for many interacting pairs of northern spotted owls. As such, the selection of reserves generally favored areas with the highest quality old-growth forests, but some areas of younger forest were also included with the expectation that they would eventually develop suitable forest structure characteristics and contribute to spatial patterns that would sustain spotted owl populations.
In this chapter, we describe expectations of the Northwest Forest Plan (NWFP, or Plan) and review recent science on the ecology and status of the marbled murrelet (Brachyramphus marmoratus), with an emphasis on the portion of the species’ range that falls within the Plan area. The conservation strategy embodied in the NWFP evolved from designation and protection of a large number of relatively small management areas to an approach based primarily on the designation of fewer large areas, each designed to conserve functioning late-successional and old-growth ecosystems. These were intended to support multiple pairs of northern spotted owls (Strix occidentalis caurina) and murrelets, and to conserve habitat for other species associated with older forests.
Given the need to conserve forest biodiversity and produce forest products, President Clinton’s vision for the Northwest Forest Plan (NWFP, or Plan) was that it would provide “a balanced and comprehensive strategy for the conservation and management of forest ecosystems, while maximizing economic and social benefits from forests” (USDA and USDI 1994: E-1). The Plan was expected to support the production of a predictable, sustainable level of timber and nontimber resources from federal forests to contribute to the stability of local and regional economies over the long term (Charnley et al. 2006a). The Plan also aimed to help rural communities affected by cutbacks in federal timber production by providing economic assistance programs to promote long-term economic development and diversification and minimize the adverse effects of job loss from reductions in timber harvesting (Dillingham 2006).