| Abstrakt: |
A science-management adaptation partnership was developed among the Columbia River Gorge National Scenic Area, Mount Hood National Forest, and Willamette National Forest, and other organizations (hereafter referred to as CMWAP) to identify climate change issues relevant for resource management in central Oregon and southern Washington). This partnership assessed the vulnerability of natural resources to climate change and developed adaptation options that minimize negative impacts of climate change and facilitate transition of ecosystems and organizations to a warmer climate. The vulnerability assessment focused on water resources and infrastructure, fisheries, vegetation, wildlife, recreation, and ecosystem services. The vulnerability assessment shows that the effects of climate change on hydrology in the CMWAP assessment area will be significant, primarily because decreased snowpack and earlier snowmelt will shift the timing and magnitude of streamflow; peak flows will be higher, and summer low flows will be lower. Projected changes in climate and hydrology will affect aquatic and terrestrial ecosystems, especially as frequency of extreme climate events (drought, low snowpack) and ecological disturbances (flooding, wildfire) increase. Distribution and abundance of coldwater fish species are expected to decrease in response to higher water temperature, although effects will vary as a function of local habitat and competition with nonnative fish. Higher air temperature, through its influence on soil moisture, is expected to cause gradual changes in the distribution and abundance of plant species, with drought-tolerant species becoming more dominant. Increased frequency and extent of wildfire (and in some cases insects) will facilitate vegetation change, in some cases leading to altered structure and function of ecosystems, although the frequency and extent of disturbances are uncertain. Vegetation change will alter wildlife habitat, with both positive and negative effects depending on animal species and ecosystem. Animal species with a narrow range of preferred habitats (e.g., riparian systems, old forest) will be the most vulnerable to more disturbance and large-scale shifts in flora. The effects of climate change on recreation activities are difficult to project, although higher temperatures are expected to create more opportunities for warm-weather activities (e.g., hiking, camping, water-based recreation) and fewer opportunities for snow-based activities (e.g., skiing, snowmobiling). Recreationists modify their activities according to current conditions, but recreation management by federal agencies has generally not been so flexible. Of the ecosystem services considered in the assessment, (1) timber supply and carbon sequestration may be affected by lower productivity and higher frequency and extent of disturbances, (2) native pollinators may be affected by altered vegetation distribution and phenological mismatches between insects and plants, and (3) decreased salmon populations will reduce the availability of an important first food for tribes in the assessment area. CMWAP resource managers developed adaptation options in response to the vulnerabilities of each resource, including high-level strategies and on-the-ground tactics. Many adaptation options are intended to increase the resilience of aquatic and terrestrial ecosystems, or to reduce the effects of existing stressors (e.g., removal of nonnative species). In aquatic systems, a dominant theme is to restore the structure and function of streams to retain cold water for fish and other aquatic organisms. In forest systems, dominant themes of adaptation are to decrease stand density and increase structural and genetic diversity to confer resilience to drought. Many adaptation options can accomplish multiple outcomes; for example, restoring the hydrologic function of streams and wetlands will benefit coldwater fish species and riparian wildlife species as well as reduce impacts on infrastructure. Many existing management practices are already "climate smart" or require minor adjustment to make them so. Long-term monitoring is needed to detect climate change effects on natural resources and evaluate the effectiveness of adaptation options. [ABSTRACT FROM AUTHOR] |
