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Per Portland University, this work was written as part of one of the atuthor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. See https://works.bepress.com/j_yeakley/32/, We discuss the importance of addressing diffuse threats to long-term species and habitat viability in fish conservation and recovery planning. In the Pacific Northwest, USA, salmonid management plans have typically focused on degraded freshwater habitat, dams, fish passage, harvest rates, and hatchery releases. However, such plans inadequately address threats related to human population and economic growth, intra- and interspecific competition, and changes in climate, ocean, and estuarine conditions. Based on reviews conducted on eight conservation and/or recovery plans, we found that though threats resulting from such changes are difficult to model and/or predict, they are especially important for wide-ranging diadromous species. Adaptive management is also a critical but often inadequately constructed component of those plans. Adaptive management should be designed to respond to evolving knowledge about the fish and their supporting ecosystems; if done properly, it should help improve conservation efforts by decreasing uncertainty regarding known and diffuse threats. We conclude with a general call for environmental managers and planners to reinvigorate the adaptive management process in future management plans, including more explicitly identifying critical uncertainties, implementing monitoring programs to reduce those uncertainties, and explicitly stating what management actions will occur when pre-identified trigger points are reached., Funding for this article was provided by the Pacific Coastal Salmon Recovery Fund via the Oregon Watershed Enhancement Board to Oregon’s Independent Multidisciplinary Science Team

We review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription must be matched to the scale of the factors that are causing the problem, and results will likely not be immediate because of lengthy recovery times. Although pristine or reference conditions are far from attainable, urban stream rehabilitation is a worthy goal because appropriate act...

Previously we examined how degraded urban streams can be rehabilitated, with emphasis on identifying solutions that match the scale of the problems (Hughes et al. 2014). Our findings showed that rehabilitation techniques are challenging but that some environmental benefits can nearly always be obtained regardless of existing conditions. Although rehabilitation is useful in many present-day situations, biologists need to consider the future and think about ways of preventing or reducing future environmental damage. We need to reduce future damage because urban areas are likely to expand greatly over the next century; if historical patterns continue, the number and length of streams experiencing urban stream syndrome will increase, with resulting high repair costs. However, there are several ways of avoiding or mitigating damage that are not only cost effective but provide benefits to humans and urban ecosystems.

Per Portland University, this work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. See https://works.bepress.com/j_yeakley/27/, Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local-and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources., Funding for this manuscript was provided by the Pacific Coastal Salmon Recovery Fund via the Oregon Watershed Enhancement Board to Oregon's IMST., https://link.springer.com/article/10.1007%2Fs10661-015-4504-8

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests managed for timber in western Oregon frequently lack structure and diversity associated with old-growth forests. We examined thinning effects on overstory and understory development for 8 years after treatment. Three 30- to 33-year-old Oregon Coast Range plantations were partitioned into four overstory treatments: unthinned (~550 trees/ha) and lightly (~250 trees/ha), moderately (~150 trees/ha), and heavily (~75 trees/ha) thinned. Within each overstory treatment, two understory treatments were established: underplanted with Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.) or not underplanted. Thinning increased overstory stem growth, crown expansion, and retained crown length. Thinned overstory canopies began to close rapidly the third year after thinning, decreasing % skylight by approximately 2%/year, whereas % skylight in unthinned stands increased slightly. All seedlings planted in unthinned stands died, whereas eighth year survival in thinned stands averaged 88%. Natural regeneration densities and distributions were highly variable. Understory shrub cover was reduced by harvesting disturbance but recovered by the fifth year. Thinning increased understory plant species diversity, and no shrub species were lost. Thinning to low densities and underplanting has the potential to accelerate development of multilayered stands characteristic of old-growth Douglas-fir forests.

Five conifers and two hardwoods native to the Pacific Northwest were planted under four overstory densities of 30-year-old plantations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range, USA. Stand treatments were unthinned (547 trees ha−1), narrow thin (252 trees ha−1), wide thin (138 trees ha−1), and very wide thin (72 trees ha−1). Conditions in the unthinned stands were lethal to both hardwoods and conifers. Eighth-year survival in thinned stands ranged from 87 to 94% for conifer species and 61 to 94% for hardwood species. Eighth-year mean heights of conifer species ranged from 2.6 to 5.4 m. On the basis of size and damage incurred during the study, we ranked conifer species in decreasing order of suitability for underplanting as western hemlock (Tsuga heterophylla (Raf.) Sarg.), Sitka spruce (Picea sitchensis (Bong.) Carr.), Douglas-fir, grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), and western redcedar (Thuja plicata Donn ex D. Don). Eighth-year mean height of red alder (Alnus rubra (Bong.)) was 7.7 m in thinned stands. Heavy and repeated browse (mostly from elk, Cervus elaphus) on bigleaf maple (Acer macrophyllum Pursh) and to a lesser degree on western redcedar led us to conclude that these species may be unsuitable for underplanting unless they can be adequately protected. The other five conifer species and red alder suffered little damage during the study and are all viable choices for underplanting where diversity enhancement is an objective. Major findings from this study are (1) underplanting was successful (good survival and size) when the overstory canopy was thinned to wide or very wide spacings and available light was markedly increased; (2) fast growth of planted seedlings such as red alder, western hemlock, and Sitka spruce can enhance stand structure early in the development of thinned stands; (3) the level of thinning intensity affects light availability in the understory and will determine the vitality and longevity of underplanted seedlings; and (4) animal damage, mostly from elk browse and antler rubbing, varied by species and by size of seedlings but can be so serious as to limit the choice of seedlings.

Efforts to restore watershed and aquatic ecosystem processes in urban areas are constrained by municipal infrastructure: bridges, dams, roads, buildings, and stormwater and sewage treatment systems (Carpenter et al. 2003; Booth 2005; Bernhardt and Palmer 2007). Consequently, rivers, streams, and estuaries in developed areas cannot be fully restored to unimpaired conditions, but in some cases can be rehabilitated to support salmonid populations. Therefore, the terms rehabilitation and enhancement are preferred over restoration when referring to improving environmental conditions in developed areas (Box 13.1; mitigation is addressed in Chap. 15). The general goals of watershed rehabilitation actions are to improve ecosystem processes so that they promote and sustain habitat connectivity, riparian vegetation, water quality, and streamflow regimes (Roni et al. 2002; Beechie et al. 2008). Enhancement approaches are used as short-term, stream-reach measures that often provide only temporary local benefits to aquatic ecosystems until self-sustaining, habitat-forming processes have been rehabilitated. Most rehabilitation and enhancement techniques (e.g., floodplain reconnection, meander construction, fish passage improvement) are implemented throughout the landscape and are not unique to urban areas but may need to be modified for these areas to account for infrastructural, social, or regulatory constraints.

We return to the central question of the book: Can viable wild salmonid populations coexist with humans in urban and urbanizing areas? In the intervening chapters, we described how urbanization degrades the habitat and viability of wild salmonid populations. We also presented a variety of potential remedies, including both social and biophysical aspects of wild salmonid rehabilitation and protection in urbanizing areas. Social remedies include policy approaches, planning strategies, market-based solutions, and citizen engagement efforts. Biophysical remedies include rehabilitation approaches both at local and watershed scales. In this final chapter, we review our major conclusions about urbanization stresses on salmonids, we summarize some of the most salient aspects of the remedies that we have presented, and we conclude with our answer to the central question of the book.

Physical habitat variables in aquatic environments include streambed substrate size, channel complexity and cover, riparian vegetation structure, and the degree and type of interaction between the channel and riparian area. Various physical processes work in combination to create a wide variety of riparian and aquatic physical habitats. Those processes include peak flow timing and magnitude; wood and sediment supply, transport, and deposition; stream bank and bed erosion; and channel migration. The spatial–temporal complexity of physical habitat conditions formed by those processes provides habitat elements critical to salmonid persistence. Rural-residential and urban development can significantly modify the processes that link aquatic ecosystems to the surrounding landscapes and directly or indirectly lead to habitat deterioration by altering hydrology, channel and substrate structure, and riparian vegetation.

Pacific Northwest salmonid populations have decreased in watersheds where a large proportion of the land is urbanized. Between the 1940s and 1990s, salmon abundance declines were greater in Puget Sound, Washington basins with higher urbanization rates than in basins with less urbanization (Moscrip and Montgomery 1997). Also in the Puget Sound region, the presence of coho salmon at urbanized sites declined by 75 % between 1986 and 2001 (Bilby and Mollot 2008). Coho salmon (Oncorhynchus kisutch) abundance also declined on lands converted to urban uses between 1984 and 1998 in the Snohomish River basin (Pess et al. 2002). Productivity was lowest in sub-watersheds with more urban land cover for 22 spring-summer Chinook (O. tshawytscha) salmon populations in eastern Oregon, eastern Washington, and Idaho (Regetz 2003). Similarly, the percent of fish assemblages composed of salmonids was lower in highly urbanized areas in western Oregon’s Willamette Valley (Waite et al. 2008).

Remedying the effects of existing and growing urban areas on water quality, flow regime, and aquatic ecosystem function is a daunting challenge. Given the tens of millions of dollars committed to watershed restoration and rehabilitation and the uncertainty associated with effectiveness, there is a need to prioritize rehabilitation actions based on their potential for benefiting salmonids and watershed functions. Restoring ecosystem processes at the watershed-scale is generally assumed to have a much greater likelihood of long-term success than reach-scale rehabilitation or enhancement of individual habitat characteristics (Beechie and Bolton 1999), but most urban rehabilitation projects are still planned at the reach scale (Beechie et al. 2008). Restoration usually aims at restoring pre-disturbance conditions while rehabilitation targets short-term or local improvements when pre-disturbance conditions cannot be readily or are unlikely to be achieved (see Chap. 13). Recognizing the distinction between restoration and rehabilitation is essential to improving urbanized aquatic habitats because human structures and values constrain what can be ecologically achieved in urban and suburban areas. This chapter examines the fundamentals of prioritizing rehabilitation in urbanizing watersheds, assessing rehabilitation effectiveness, and communicating those results to multiple audiences.