Ecological vulnerability and species response to climate variability and change

Climate change is expected to cause stressful environmental conditions for the majority of global biodiversity in the coming decades, and there is concern that many species will not be able to keep pace with direct and indirect impacts (Loarie et al., 2009). Biological responses to climate change are occurring as shifts in time (e.g., phenology), space (e.g., geographical range) and organism (e.g., physiology) throughout terrestrial, aquatic, and marine habitats in the Northern Hemisphere and across the northeast region (Staudinger et al., 2013). Species-specific responses to multiple climate drivers (e.g., temperature, water availability) are causing changes in the timing, direction, and magnitude of movements and life events among biota and regions and may have adverse impacts on the distribution and viability of biological communities, species and populations. Changes in species’ range and phenology are also altering trophic relationships, shifting community assemblages, and increasing the potential for asynchronies, disruptions, and novel biotic relationships between dependent species (Miller-Rushing et al., 2010). Ultimately, the reshuffling of communities and declines of flora and fauna in northeast/midwest habitats have the potential to impact ecosystem structure, function, and productivity, threatening the many goods and services that humans depend on (Leadley et al., 2010; Mace et al., 2012). Biodiversity and ecosystem services are intrinsically linked, and biodiversity is often considered an ecosystem service in itself. However, in many cases, the relationships between biodiversity, ecosystem processes, and ecosystem services are complex and not well understood, making predictions of how the delivery of ecosystem services in the Northeast region will be altered due to climate change uncertain (Mace et al., 2012). 
 
The characterization and modeling of ecological impacts and projected future changes across the region is the ultimate goal of much of the work of the NE CSC. Research on wildlife and fisheries habitats, populations and communities are the traditional focus of most natural resource agencies (often targeted towards vulnerable or other trust species), but requires a broad and deep research program at all levels of organization from individual organisms to ecosystems. 
 
The vulnerability of species and habitats to climate change is dependent on the degree (character, rate, and magnitude) of exposure to changing conditions, sensitivity (or responsiveness) to those changes, and inherent adaptive capacity to adjust to those changes (IPCC 2007; Glick et al 2011). Understanding what traits make some species and habitats relatively more vulnerable to regional climate changes (e.g., increasing temperature and precipitation extremes) than others will be critical to designing adaptation strategies in the northeast CSC region. Populations and habitats already under stress from land-use change, exploitation, pollution, and biological disturbances are likely to be more vulnerable to the impacts of climate change and at risk for declines (Staudt et al., 2013). Therefore, approaches that improve our understanding of how climate drivers are expected to change in the Northeast region (Theme 1), as well as the synergistic and interactive effects of land-use change (Theme 2) are needed to inform conservation, restoration, and adaptive management approaches. 
 
Research conducted under this theme will incorporate historical datasets, on-going broad-scale monitoring efforts by both management and research agencies, targeted field and laboratory experiments, comparative analyses, and modeling studies. Results of this wide range of studies will be used to establish baselines, track population shifts, identify critical thresholds, and improve our understanding of the physiological, behavioral, and ecological mechanisms that cause populations and habitats in the Northeast CSC region to respond to climate change in variable ways. Improved modeling approaches that incorporate these types of data as well as information on species demographics, dispersal abilities, evolutionary processes, and trophic interactions will help improve forecasts of which species will be successful and those that may decline under future climate scenarios. In addition, the parameterization of a new generation of linked climate, population, and ecological models will provide science support for management decisions (e.g., to evaluate connections or corridors among terrestrial, aquatic, and coastal systems). The NE CSC is committed to adaptive management approaches that are flexible and manage for future changes rather than solely focusing on maintaining or restoring historical conditions and ecological communities (Stein et al., 2013). Ideally, management actions resulting from NE CSC research will be used to reduce uncertainties in ecological responses and vulnerabilities, increase resiliency, and inform the next generation of tools and techniques to best manage habitats and species under climate change. 
 
Recommendations
 
  • Document how species and ecosystems were historically distributed, how they have adapted to past global change, and use this information to evaluate the relative vulnerability or resilience of specific natural resources to potential future changes. 

  • Determine the synergistic effects of climate change and other environmental and anthropogenic stressors prevalent in the northeast region, including changes in land-use and habitat connectivity, disturbance regimes, non-native invasive species, disease, and pollution. 

  • Characterize climate change impacts on priority, endangered, and threatened (Federal and State) freshwater and migratory (e.g., anadromous and catadromous) fishes, fisheries, and wildlife resources. 

  • Improve the understanding of relationships between regional biodiversity, ecological systems, and ecosystem services. 

  • Assess how climate change impacts on fish, wildlife, and ecosystems will affect the delivery of regional ecosystem services, and identify approaches to increase resilience and the sustainability of ecosystem services across the northeastern region. 

  • Work with partners to develop predictive models (e.g., abundance, range, and distribution changes; population viability) and promote tools to identify habitats, species, and populations that are either particularly resilient or vulnerable to climate change in the northeast region (e.g., barrier islands, Great Lakes islands, headwaters, mountain and alpine habitats, prairies, coastal wetlands and their associated fish and wildlife populations). 

  • Work with partners to link models of specific climate drivers (e.g., temperature, precipitation, lake or sea level changes) with population (e.g., survival and size-structure) or ecological (e.g., production and food-web dynamics) models to better understand temporal (e.g., seasonal) and spatial (e.g., distribution) changes in plants and animals. 

  • Work with partners to develop products (e.g., databases, maps, and factsheets) that summarize habitat and species transitions predicted by downscaled climate and linked population and ecological models. 

  • Use decision analysis frameworks to identify and prioritize restoration and adaptive management approaches and discern their relative effectiveness and necessary implementation thresholds that can help to improve the resilience of populations and habitats, including assisted migrations of populations, increasing habitat connectivity, maintenance of genetic and life-history diversity, and changes in harvest or habitat management techniques. 

  • Advise and work collaboratively with LCCs, State, Tribal, and other partners (e.g., Association of Fish & Wildlife Agencies) to link fish and wildlife adaptation management plans (e.g., State Wildlife Action Plans; National Fish, Wildlife and Plants Climate Adaptation Strategy) across state and LCC boundaries to adequately respond to multiple anthropogenic and climate stressors, as well as shifting populations and geographic ranges.