The extensive mortality of yellow-cedar along more than ¡000 kilometers of the northern Pacific coast of North America serves as a leading example of climate effects on a forest tree species. In this article, we document our approaches to resolving the causes of tree death, which we explain as a cascade of interacting topographic, forest-structure, and microclimate factors that act on a unique vulnerability of yellow-cedar to fine-root freezing. The complex causes of tree mortality are reduced to two risk factors-snow depth and soil drainage-which are then used to model present and future cedar habitat suitability. We propose a dynamic, comprehensive conservation strategy for this valuable species on the basis of zones created by shifting climate, cedar's ecological niche, and observed risk factors. Research on yellow-cedar decline is offered as a template for understanding and adapting to climate change for other climate-forest issues.

We synthesized an expert review of climate change implications for hydroecological and terrestrial ecological systems in the northern coastal temperate rainforest of North America. Our synthesis is based on an analysis of projected temperature, precipitation, and snowfall stratified by eight biogeoclimatic provinces and three vegetation zones. Five IPCC CMIP5 global climate models (GCMs) and two representative concentration pathways (RCPs) are the basis for projections of mean annual temperature increasing from a current average (1961-Climatic Change (2015 1990) of 3.2°C to 4.9-6.9°C (5 GCM range; RCP4.5 scenario) or 6.4-8.7°C (RCP8.5), mean annual precipitation increasing from 3130 mm to 3210-3400 mm (3-9 % increase) or 3320-3690 mm (6-18 % increase), and total precipitation as snow decreasing from 1200 mm to 940-720 mm (22-40 % decrease) or 720-500 mm (40-58 % decrease) by the 2080s (2071-2100; 30-year normal period). These projected changes are anticipated to result in a cascade of ecosystem-level effects including: increased frequency of flooding and rain-on-snow events; an elevated snowline and reduced snowpack; changes in the timing and magnitude of stream flow, freshwater thermal regimes, and riverine nutrient exports; shrinking alpine habitats; altitudinal and latitudinal expansion of lowland and subalpine forest types; shifts in suitable habitat boundaries for vegetation and wildlife communities; adverse effects on species with rare ecological niches or limited dispersibility; and shifts in anadromous salmon distribution and productivity. Our collaborative synthesis of potential impacts highlights the coupling of social and ecological systems that characterize the region as well as a number of major information gaps to help guide assessments of future conditions and adaptive capacity.

Global climate change may become one of the most pressing challenges to Pacific Salmon conservation and management for southeast Alaska in the 21st Century. Predicted hydrologic change associated with climate change will likely challenge the ability of specific stocks to adapt to new flow regimes and resulting shifts in spawning and rearing habitats. Current research suggests egg-to-fry survival may be one of the most important freshwater limiting factors in Pacific Salmon's northern range due to more frequent flooding events predicted to scour eggs from mobile spawning substrates. A watershed-scale hydroclimatic sensitivity index was developed to map this hypothesis with an historical stream gauge station dataset and monthly multiple regression-based discharge models. The relative change from present to future watershed conditions predicted for the spawning and incubation period (September to March) was quantified using an ensemble global climate model average (ECHAM5, HadCM3, and CGCM3.1) and three global greenhouse gas emission scenarios (B1, A1B, and A2) projected to the year 2080. The models showed the region's diverse physiography and climatology resulted in a relatively predictable pattern of change: northern mainland and steeper, snow-fed mountainous watersheds exhibited the greatest increases in discharge, an earlier spring melt, and a transition into rain-fed hydrologic patterns. Predicted streamflow increases for all watersheds ranged from approximately 1-fold to 3-fold for the spawning and incubation period, with increased peak flows in the spring and fall. The hydroclimatic sensitivity index was then combined with an index of currently mapped salmon habitat and species diversity to develop a research and conservation priority matrix, highlighting potentially vulnerable to resilient high-value watersheds. The resulting matrix and observed trends are put forth as a framework to prioritize long-term monitoring plans, mitigation experiments, and finer-scale climate impact and adaptation studies.

Abstract. The road-effect zone is the area in which ecological effects extend outward from a road.Dispersed off-highway vehicle (OHV; e.g., four-wheelers and snowmachines) activity on rural road networks creates a disturbance that reduces the effective amount of wildlife habitat and therefore has the potential for an extensive road-effect zone. Consequently, land managers must consider the trade-offs between rural road development and the conservation of habitat for species of concern. We conducted a spatially-explicit study of moose, Alces alces, occurrence in relation to rural roads and OHV routes in rural Alaska, U.S.A. We used logistic regression and AIC model selection criterion to develop resource selection functions (RSFs) for male and female moose at three spatial scales (250 m, 500 m, and 1000 m) in two seasons (summer and fall). To evaluate an ecological disturbance threshold from increasing route activity on the probability of animal occurrence, the RSFs were plotted against an index of route activity derived from interviews with OHV users, and fit with logarithmic functions. The variable for route activity improved the fit of RSF models for both sexes at all spatial scales and in both seasons. A negative relationship was found between moose occurrence and routes or areas in which routes were in close proximity to primary forage, with the exception of male moose at the 1000-m scale in the fall. Therefore, among the spatial scales of analysis, the road-effect zone for male moose was determined to be between 500 m and 1000 m, and .1000 m for female moose. Furthermore, route activity ,0.25 km of vehicle travel/km 2 / day was a threshold value at which moose sustained a high probability of occurrence (0.60 to 0.91). The results of our study suggest that the dispersed ecological effect of rural roads and OHV routes should be considered in transportation and land-management planning efforts. Relatively low levels of vehicular activity may create extensive road-effect zones for sensitive species.