Setting conservation priorities in a changing climate: New tools for identifying and connecting climate refugia

Setting conservation priorities in a changing climate: New tools for identifying and connecting climate refugia

Carlos Carroll
Klamath Center for Conservation Research (KCCR)
Time Slot: 
Tuesday 11:10am - Concurrent Session 1
Session Type: 
Symposium (Individual Presentations)

The unprecedented challenge of climate change has led planners to search for new types of information for identifying climate refugia and other areas whose conservation would facilitate persistence of biodiversity under climate change. This symposium will feature presentations by researchers who are working to compare and combine different approaches to devise regional conservation plans that identify key refugia and connect them to maximize landscape-level adaptive capacity. Speakers will describe several approaches for identifying potential refugia, including a focus on areas of diverse geophysical settings (land facets), and a focus on climatic refugia for particular species, and will show how regional planners can integrate data from a variety of sources to identify a conservation network resilient to threats operating at multiple scales. Speakers will discuss strategies for identifying and conserving both macrorefugia (areas where broad-scale climate is suitable for persistence) and microrefugia (small areas with locally favorable environments), as well as methods for identifying climate corridors, and approaches for communicating climate resilience information. The goal of the session is to help build connections between researchers, planners, land managers, and others interested in conserving adaptive capacity across broad landscapes.


Conserving both the stage and the actors: a unified approach to safeguarding landscape-level adaptive capacity
Carlos Carroll, KCCR
hide abstract

As the earth transitions to altered climatic conditions, new methods are needed to identify areas whose conservation would facilitate persistence of biodiversity under climate change. We compared several common approaches to conservation planning focused on climate resilience over a range of ecological settings across North America and evaluated how commonalities in the priority areas identified by different methods varied with regional context and spatial scale. Our results indicate that priority areas based on different environmental diversity metrics differed substantially from each other and from priorities based on spatiotemporal metrics such as climatic velocity. Refugia identified by diversity or velocity metrics were not strongly associated with the current protected area system, suggesting the need for additional conservation measures including protection of refugia. Despite the inherent uncertainties in predicting future climate, we found that variation among climatic velocities derived from different general circulation models and emissions pathways was less than the variation among the suite of environmental diversity metrics. To address uncertainty created by this variation, coarse-resolution velocity metrics can be combined with fine-resolution diversity metrics in order to leverage the respective strengths of the two groups of metrics as tools for identification of potential macro- and micro-refugia that in combination maximize both transient and long-term resilience to climate change. Planners should compare and integrate approaches that span a range of model complexity and spatial scale to match the range of ecological and physical processes influencing persistence of biodiversity and identify a conservation network resilient to threats operating at multiple scales.

Identifying climate refuges and disappearing climates in North America's protected areas
Julia Michalak, University of Washington
hide abstract

As the earth’s climate continues to change, many species will likely struggle to track shifting and shrinking climates. As evidenced by past climatic refugia, locations projected to harbor remnants of present day climates may serve as critical refuges for current biodiversity as the climate changes. Identifying these refuges is challenging given the uncertainties associated with anticipating future climatic conditions and subsequent species’ responses. Here, we present a novel approach to locating potential climate refuges by tracking changes in the size and distribution of climate analogs over time. We identified potential refuge sites across North America and assessed the extent to which they are included in current protected areas. We identified at most 12% of North America as potential climate refuges. Existing conservation areas protect up to 25% of identified refuges, indicating that protected areas disproportionately include refuges relative to the general landscape. Based on our results, a 23% expansion of the protected areas network would be sufficient to protect the most robust refuge locations, increasing the network’s refuge potential. Refuges were smaller or disappeared entirely under warmer climate-change scenarios, suggesting that our ability to limit climate change will greatly impact the availability of adaptation options.

Identifying locations and drivers of multi-species macrorefugia for North American trees and birds
Diana Stralberg, University of Alberta
hide abstract

Identifying climate refugia is a key component of climate-smart conservation planning. Although conceptually straightforward, quantitative approaches for locating biologically relevant climate refugia are lacking. Using distribution models for 325 tree and 263 songbird species within North America, we developed a species-level refugia index based on biotic climate velocity, and generated maps of multi-species refugia potential for each taxonomic/functional group. We found that end-of-century refugia for both trees and songbirds were concentrated at the cold and wet extremes of temperature and moisture gradients: in western mountains and, to a lesser extent, northern coastal regions. We also found substantial differences in refugia patterns, with greater tree refugia potential in boreal and temperate forest regions, and greater songbird refugia potential in northern and intermountain-western regions. Climate variables were more explanatory of biotic refugia patterns than terrain and continental position variables. The strongest environmental correlates of tree refugia were precipitation seasonality and moisture availability, whereas maximum summer temperature was most constraining for songbirds. For both groups, we found relatively strong effects of landform composition, especially headwaters, indicating a potential to provide useful first approximations of refugia, while also helping to delineate ecological units (land facets) for conservation planning. We found a general lack of concordance between patterns of current species richness and future climate refugia, suggesting the need for large-scale “bet-hedging” in the development of long-term conservation designs. Our framework can be applied to other regions and taxa to generate biologically meaningful indices of macrorefugia potential for conservation planning purposes.

Getting species from here to there: A review of connectivity modeling approaches for climate adaptation
Meade Krosby, University of Washington
hide abstract

As global temperatures rise, many species are responding by adjusting their ranges to track shifting areas of climatic suitability. For this reason, enhancing ecological connectivity – the ability of landscapes to facilitate movement of the organisms within them – is the most frequently cited climate adaptation strategy for biodiversity conservation, and a key component of many regional and national adaptation plans. Although a wide range of methods exists for modeling connectivity under static climates, climate change creates a pressing need for new analytical approaches for modeling climate connectivity – the ability of landscapes to accommodate species range shifts in response to climate change. Indeed, climate-connectivity models aimed at identifying corridors for climate-induced range shifts have proliferated in recent years. These approaches vary widely, from what they target (e.g., species, biomes, or enduring features), to whether and how they incorporate future climate projections. We review and synthesize climate-connectivity modeling approaches in an effort to clarify the state of this rapidly evolving field, stimulate further innovation, and support informed implementation of connectivity enhancement as a key adaptation strategy for biodiversity conservation under a changing climate.

  • Caitlin Littlefield, University of Washington
  • Julia Michalak, University of Washington
Connecting current and future suitable climates to facilitate species movement under climate change
Caitlin Littlefield, University of Washington
hide abstract

Increasing connectivity is important for facilitating species range shifts and maintaining biodiversity in the face of climate change. However, few studies have included future climate projections in efforts to prioritize areas for increasing connectivity. Here, we identify key areas likely to facilitate climate-induced species movement across western North America. Using historical climate datasets and future climate projections, we mapped potential routes between current climates and their future analogs using a novel moving-window analysis based on electrical circuit theory. In addition to tracing shifting climates, the approach accounts for landscape permeability and empirically-derived species dispersal capacities. We compared connectivity maps generated with our climate-change informed approach to maps of connectivity based solely upon the degree of human modification of the landscape. We show that including future climate projections in connectivity models substantially shifts and constrains priority areas for movement to a smaller proportion of the landscape than when climate projections are not considered. Predicted movement decreases in all ecoregions when climate projections are included, particularly when dispersal capacities are highly constrained, making climate analogs inaccessible. In addition, many areas emerge as important for connectivity only when climate change is modeled in two time steps rather than in a single time step. Our results illustrate that movement routes needed to track changing climatic conditions may differ from those that connect present-day landscapes. Incorporating future climate projections into connectivity modeling is important for conservation planners to understanding how to best facilitate successful species movement and persistence of biodiversity in a changing climate.

  • Brad McRae, The Nature Conservancy
  • Julia Michalak, University of Washington
  • Joshua Lawler, University of Washington
  • Carlos Carroll, Klamath Center for Conservation Research
A National Assessment of Wildland Values and Climate Change Vulnerabilities to Guide Conservation Strategy
Travis Belote, The Wilderness Society
hide abstract

Climate change challenges traditional conservation strategies aimed at sustaining biodiversity of wildlands. We conducted a national assessment of wildland values and climate change vulnerability of the contiguous U.S. to help guide conservation strategies. Wildland conservation values were mapped as a composite of data depicting wildness, connectivity, and the degree of representation of habitats and species in protected areas. Climate change vulnerability was based on projected forward and backward velocity and multivariate dissimilarity. In addition, we assessed agreement in climate change models, emissions scenarios, and climate change metrics. We simultaneously mapped wildland values and climate vulnerability, including an assessment of uncertainty in climate vulnerability. Given our assessment, we propose a portfolio of conservation strategies be applied depending on relative value and vulnerability. The portfolio includes restoration of degraded areas with low climate vulnerability, innovative approaches in degraded areas with high vulnerability, and observation of ecological change in high value and low vulnerability areas. Given uncertainty of models, the portfolio should be applied to all lands, but our framework and analysis should inform conservation decisions based on existing conditions and projected climate impacts.