This objective complements Adaptation Objective 2 by recognizing that species and their habitats could shift their distributions in response to climate change. It takes the further step to identify where that movement will likely take place across the landscape and accordingly identifies current and potential future travel routes and impediments (such as terrain, vegetation, human land use, and geological barriers) to movement.
The goal is to ensure that species will be able to reach new locations that can support their populations as climate changes. While increasing habitat connectivity to facilitate gene flow and decrease the incidence of local extinction is usually the focus of conservation efforts, climate change could also create corridors that reduce wildlife populations by increasing disease transmission, colonization of exotic species, or lead to non-analog communities.
Overview
- Identify areas critical to species movements in a changing climate
- Map movement corridors for species life-history and migration
Details
An assessment approach at this level aims to identify areas or features of landscapes that are important for species movement across landscapes in order to maintain viable populations and gene flow in the face of climate change. A variety of approaches and tools are available to conduct such analyses.
These approaches essentially identify or simulate potential movement pathways for species across a landscape using data on biophysical attributes of the landscape (such as terrain, vegetation, land use, geological barrier, etc.) in conjunction with data on species habitat needs. This approach estimates the relative ease of travel, in terms of relative resistance to or cost of travel between two locations. The input data of physical geographic characteristics and species-specific habitat requirements may be highly certain, but the output, or least-cost path, may be highly uncertain unless it is validated through monitoring of species movements.
The approaches can be extended to identify areas needed to facilitate future movement in response to climate change by using existing landscape features combined with data on changes in landscape attributes derived from assessment at the ecosystem level of analysis for Adaptation Objective 2. This kind of assessment can help to inform how species might move through the landscape beyond their current distribution. One can also use predicted shifts in species distributions to map corridors and connections.
Approaches and Tools
Here is a sample of tools commonly used to assess and map species ability and willingness to traverse among natrural and human-modified landscape features. When assessing and predicting species movement on a landscape, practitioners should build off existing information on the species movement behavior in the literature and expert opinions. For example, if information on species ability or inability to traverse steep terrain has been previously determined an important factor influencing movements then an elevation raster and slope model should be used when mapping species movements.
Pilot Projects
NatureServe
Overview
- Map connections between current and projected future locations
- Anticipate species invasions along planned corridors
Details
Climate warming stands to reorganize communities and associated ecosystems across landscapes because species existing within a community will not all respond in the same way to this stressor. Some species may tolerate changes in particular climatic conditions, while others may shift their geographic ranges–although they may not necessarily move in identical directions.
Assessments for this level of analysis aim to determine where the habitats for species will move and identify important conduits on the landscape that facilitate such movement. Such assessments can build on insights gained from the ecosystem assessment for Adaptation Objective 2. Essentially, one uses maps of current and future vegetation in conjunction with movement models applied to a variety of species.
Approaches and Tools
Species-level tools are commonly used to address connectivity at an ecosystem level (e.g., Least-cost path, Circuit theory, and Graph network). Instead of constructing species-specific models, the model inputs reflect key biological parameters associated with ecosystem function.
Least-cost pathways to identify migratory corridors between current and projected ecosystems and protected areas
Identify corridors that facilitate key biotic interactions to stabilize ecosystem function (e.g., least-cost paths for both predator and prey species)
Map genetic connectivity for key species in an ecosystem
Map corridors that provide an opportunity to conserve ecological processes such as natural fire regimes
Pilot Projects
NatureServe
Overview
- Map connections between land facets, ecological land units, refugia or areas of high ecological integrity
- Map hydrologic connectivity to maintain upstream-downstream connections in riverine systems
Details
Given that animal and plant species are expected to shift their geographic ranges in response to changing climate, we recommend that assessments also explicitly identify land facets or ecological land units, refugia, and/or areas of high ecological integrity, and then map connections among these areas using circuit theory or graph theory models.
Approaches and Tools
A new modeling tool has been developed that takes into account natural linkages and future shifts in climate gradients, Climate Linkage Mapper. This method has been implemented as the Climate Linkage Mapper software tool, which is a new addition to the Linkage Mapper Toolkit for ArcGIS.
- Climate Linkage Mapper: a tool that maps corridors following climatic gradients to facilitate species range shifts under climate change.
Pilot Projects
Geos Institute
NatureServe
Species and populations