OOS 28-6 - Using adaptive-capacity assessments to evaluate climate-change vulnerabilities, link to mechanisms of climatic influence, and identify potential climate-adaptation actions: An Oregon Coast example

In response to the pervasive influence of contemporary climate change (which encompasses both ‘pulse’ and ‘press’ disturbance events for species and populations), species and populations can either move, adapt, acclimate, or decline and die. Although climate-change vulnerability (CCV) has traditionally been characterized as reflecting exposure, sensitivity, and adaptive capacity (AC). Often, assessments either exclude adaptive capacity, or incorrectly assume it to be the inverse of sensitivity. As part of a larger effort for characterizing and exploring management futures for the Oregon Coast Range, we led the assessment of adaptive capacity of nine focal wildlife species that are distributed across the eight broad vegetation types of the Coast Range. The broader process involved: 1) projecting vegetation changes over the next century; 2) assessing potential effects of climate change on focal vegetation types that occur within the broad vegetation types; and 3) our wildlife AC assessments, which sought to illustrate vulnerabilities and capacities of species that species have. In addition to evaluating each of the three CCV sub-components, we also explored adaptation measures and management strategies that could help ameliorate negative consequences of contemporary climate change.
Climate-change influences included both deterministic trends in temperature, precipitation, and sea level as well as greater frequency of extreme events, plus both direct and indirect pathways. It was more difficult to assess sensitivity and adaptive capacity of broad vegetation types (e.g., oak-savanna woodland, coastal meadows and grasslands, montane forest and meadows), given the individualistic nature of observed paleontological and contemporary responses across species, even within a given ecological guild. Nonetheless, thinking about potential community- to regional-scale ecological transformations, macrorefugia, and intraspecific variability in genetic, behavioral, movement, and other phenotypic classes can provide insights to managing species in shifting habitat mosaics. Assessments of AC suggested that beavers have the fewest low-AC and the most high-AC attributes, indicating lesser CCV. The Northern rubber boa, Oregon silverspot butterfly, and Rufous hummingbird each had >25% of their attributes assessed as Unknown, highlighting the challenges of conservation-focused management of poorly understood taxa. Distribution of High- and Low-AC ratings across the seven attribute complexes (e.g., Movement, Distribution, Demography, Evolutionary Potential) indicated pathways by which taxa may become rare or imperiled by disturbances such as climate change as well as potential climate-adaptation actions.