Trends in Developed Land Cover Adjacent to Habitat for Threatened Salmon in Puget Sound, Washington, U.S.A.

For widely distributed species at risk, such as Pacific salmon (Oncorhynchus spp.), habitat monitoring is both essential and challenging. Only recently have widespread monitoring programs been implemented for salmon habitat in the Pacific Northwest. Remote sensing data, such as Landsat images, are therefore a useful way to evaluate trends prior to the advent of species-specific habitat monitoring programs. We used annual (1986-2008) land cover maps created from Landsat images via automated algorithms (LandTrendr) to evaluate trends in developed (50-100% impervious) land cover in areas adjacent to five types of habitat utilized by Chinook salmon (O. tshawytscha) in the Puget Sound region of Washington State, U.S.A. For the region as a whole, we found significant increases in developed land cover adjacent to each of the habitat types evaluated (nearshore, estuary, mainstem channel, tributary channel, and floodplain), but the increases were small (<1% total increase from 1986 to 2008). For each habitat type, the increasing trend changed during the time series. In nearshore, mainstem, and floodplain areas, the rate of increase in developed land cover slowed in the latter portion of the time series, while the opposite occurred in estuary and tributary areas. Watersheds that were already highly developed in 1986 tended to have higher rates of development than initially less developed watersheds. Overall, our results suggest that developed land cover in areas adjacent to Puget Sound salmon habitat has increased only slightly since 1986 and that the rate of change has slowed near some key habitat types, although this has occurred within the context of a degraded baseline condition

Rates and pathways of recovery for sediment supply and woody debris recruitment in northwestern Washington streams, and implications for salmonid habitat restoration

Thesis (Ph. D.)--University of Washington, 1998This dissertation describes a strategy for restoring watershed processes. The restoration strategy is driven by the recognition that (1) salmonids are adapted to local environmental conditions, and (2) spatial and temporal variations in landscape processes create a dynamic mosaic of habitats in a river network. Therefore, the strategy's goal is to restore and maintain the habitat-forming processes to which salmonids are adapted. Comparisons of current rates to historic rates highlight areas where restoration is necessary. The strategy then allows for prioritizing restoration actions. Prioritization does not alter the types of actions that may be taken, but alters the sequence in which they are implemented.Analyses of sediment supply and large woody debris (LWD) recruitment in the context of the natural disturbance regime allow prediction of recovery rates for salmonid habitats. Sediment supply is most significantly affected by changes in mass wasting rates. Stands less than 20 years old have mass wasting rates approximately four times that of mature forest areas, and roads have mass wasting rates approximately 40 times that of mature forest areas. The cumulative effect in a watershed is to increase average annual sediment supply under a forest management regime to about twice that of the natural fire regime. The rate of recovery for sediment supply can be described in terms of average annual travel distance of sediment, which averages about 20 times channel width where channel slope is less than 0.03.LWD recruitment in the study area has been altered by previous logging practices and conversion to agricultural and urban land uses. Compared to projected LWD recruitment under the natural fire regime, forest management typically reduces recruitment of LWD large enough to form pools by an estimated 35 to 100%. Recovery rates for LWD recruitment are primarily a function of channel size and the tree species colonizing a disturbed riparian area. Modeling of LWD recruitment through time predicts that active management of riparian forests will most effectively increase recovery rates in large streams, and that active management is unlikely to improve LWD recruitment in any channel less than 15 or 20 m wide

Process-based principles for restoring river ecosystems

Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat dynamics; and riparian and aquatic biota. We outline and illustrate four process-based principles that ensure river restoration will be guided toward sustainable actions: (1) restoration actions should address the root causes of degradation, (2) actions must be consistent with the physical and biological potential of the site, (3) actions should be at a scale commensurate with environmental problems, and (4) actions should have clearly articulated expected outcomes for ecosystem dynamics. Applying these principles will help avoid common pitfalls in river restoration, such as creating habitat types that are outside of a site's natural potential, attempting to build static habitats in dynamic environments, or constructing habitat features that are ultimately overwhelmed by unconsidered system drivers

Modeling riparian species occurrence from historical surveys to guide restoration planning in northwestern USA

Abstract Successful restoration of riparian habitats and functions depends in part on selection of plant species that are suited to local geomorphic and climatic conditions, which often relies on contemporary reference sites to characterize target riparian vegetation communities. In heavily modified landscapes, a lack of undisturbed sites hinders the description of reference conditions to help guide planning efforts. In lieu of contemporary reference sites, we used historical Public Land Survey data from the late 1800s and early 1900s to document historical streamside vegetation at 1685 sites distributed throughout the Columbia River basin. We used those data to construct a random forest classification model using climatic and geomorphic variables to predict the probability of occurrence of riparian vegetation groups (conifer, deciduous, shrub, and willow) and individual taxa (fir, pine, cedar, cottonwood, alder, sagebrush) for all stream reaches with bankfull width >6 m in the interior Columbia River basin. The most common predictor variables included in the best models for vegetation groups or individual taxa were mean annual precipitation, minimum temperature, elevation, and bankfull width. For some taxa, temperature range and floodplain width were also important predictors. The probability maps indicate that riparian zones were likely dominated by willow species in semi‐desert regions and by conifer species in the humid mountain regions. Deciduous species dominated riparian areas in transition zones between conifer forests and semi‐deserts. Species distributions suggest that streams in the semi‐deserts were likely characterized by little shade and low wood abundance, whereas streams in the humid mountains would have been more heavily shaded with high wood abundance. The transitional deciduous areas were likely shaded with moderate wood abundance. Historical trends in air temperature and precipitation suggest relatively small changes in climate since the time of the surveys, indicating that current species ranges are likely similar to historical species ranges. Hence, these maps can be used to help identify suitable taxonomic groups and expected riparian functions for riparian restoration in the Columbia River basin, with appropriate adjustments made to site‐specific restoration designs to account for model uncertainty, future climate change, or land use constraints

Channel-planform evolution in four rivers of Olympic National Park, Washington, USA: the roles of physical drivers and trophic cascades

Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, USA, to investigate whether physical or trophic-cascade-driven ecological factors – excessive elk impacts after wolves were extirpated a century ago – are the dominant drivers of channel planform in these gravel-bed rivers.We find that channel width and braiding show strong relationships with recent flood history. All four rivers widened significantly after having been relatively narrow in the 1970s, consistent with increased flood activity since then. Channel planform also reflects sediment-supply changes, evident from landslide response on the Elwha River. We surmise that the Hoh River, which shows a multi-decadal trend toward greater braiding, is adjusting to increased sediment supply associated with rapid glacial retreat. These rivers demonstrate transmission of climatic signals through relatively short sediment-routing systems that lack substantial buffering by sediment storage. Legacy effects of anthropogenic modification likely also affect the Quinault River planform. We infer no correspondence between channel evolution and elk abundance, suggesting that trophic-cascade effects in this setting are subsidiary to physical controls on channel morphology. Our findings differ from previous interpretations of Olympic National Park fluvial dynamics and contrast with the classic example of Yellowstone National Park, where legacy effects of elk overuse are apparent in channel morphology; we attribute these differences to hydrologic regime and large-wood availability

Aligning environmental management with ecosystem resilience: a First Foods example from the Confederated Tribes of the Umatilla Indian Reservation, Oregon, USA

The concept of "reciprocity" between humans and other biota arises from the creation belief of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). The concept acknowledges a moral and practical obligation for humans and biota to care for and sustain one another, and arises from human gratitude and reverence for the contributions and sacrifices made by other biota to sustain human kind. Reciprocity has become a powerful organizing principle for the CTUIR Department of Natural Resources, fostering continuity across the actions and policies of environmental management programs at the CTUIR. Moreover, reciprocity is the foundation of the CTUIR "First Foods" management approach. We describe the cultural significance of First Foods, the First Foods management approach, a resulting management vision for resilient and functional river ecosystems, and subsequent shifts in management goals and planning among tribal environmental staff during the first decade of managing for First Foods. In presenting this management approach, we highlight how reciprocity has helped align human values and management goals with ecosystem resilience, yielding management decisions that benefit individuals and communities, indigenous and nonindigenous, as well as human and nonhuman. We further describe the broader applicability of reciprocity-based approaches to natural resource management

Appendix C. A description of classification schemes mapped in this research and identifying characteristics and scales used in digitization.

A description of classification schemes mapped in this research and identifying characteristics and scales used in digitization

Appendix A. Monthly median historical (1949) and modern (2006) stream discharge, as well as median monthly discharge and range (maximum and minimum discharge) spanning 1929–2007 for the Wenatchee River below Leavenworth, Washington, USA.

Monthly median historical (1949) and modern (2006) stream discharge, as well as median monthly discharge and range (maximum and minimum discharge) spanning 1929–2007 for the Wenatchee River below Leavenworth, Washington, USA

Appendix B. A comparison of coarse- and fine-scale landscape views using aerial photography.

A comparison of coarse- and fine-scale landscape views using aerial photography

Appendix D. A comparison of characteristics between transitioning reaches (identified in Table 4) and the reaches which did not transition to a different reach type from 1949 to 2006.

A comparison of characteristics between transitioning reaches (identified in Table 4) and the reaches which did not transition to a different reach type from 1949 to 2006