Already in 1985, biologists Peters and Darling recognized the threat climate change is posing for reserves. Without corridors, populations could become isolated and unable to migrate out of the reserve to colonize suitable habitat. To overcome this shortcoming, the authors made recommendations for locating and managing reserves to enable species to persist and adapt to changing climatic conditions.
Since then, climate-wise connectivity that specifically facilitates animal and plant movement in response to climate change has become one of the most commonly cited conservation strategies for climate adaptation, and the number of original papers addressing the issue has been increasing rapidly since 2011.
A recent study reviewed a multitude of approaches to modeling and mapping climate-wise connectivity. The review categorizes approaches into two major connectivity categories: “focal species-based” and “structural”. Focal species-based models seek to maintain or improve connectivity based on the needs of specific species. They combine species distribution models with climate model projections to link current and future suitable habitats, taking dispersal abilities into account. Structural connectivity approaches, such as land facet corridors, climate gradient corridors, or lattice work corridors, aim to accommodate the movement needs of a wide range of species. Structural approaches often rely less on specific climate projections, and instead on mechanistic relationships between landscape, climate, and habitat.
Some approaches use climate projections to design or prioritize corridors that connect current habitat to habitat that will be suitable in the future (i.e., climate analogs). Other approaches seek to minimize climate velocity (the speed at which the temperature changes across the landscape) within the corridors and/or within the habitat nodes. They do this by designing corridors that maximize microclimate and topographic diversity, or by ensuring that corridors span thermal and moisture gradients.
The review provides an overview of the different approaches, and a discussion of advantages and disadvantages. The authors help practitioners and planners put the models into practice by offering guidance for selecting a connectivity modeling approach based on the conservation objectives, the desired outcome, and available data. They also suggest ways to include refugia into climate-wise connectivity designs, and review tools and software to operationalize the models.
While the models can be computationally complex, there are two simple guidelines for climate-wise connectivity designs. First, riparian corridors should be included in most connectivity plans because of their importance as natural movement corridors, climate gradients, and refugia. Second, wide corridors (> 1 km) are more functional than narrow corridors because they tend to offer more diverse microclimates and provide live-in habitat for slow dispersers.
Keeley ATH, DD Ackerly, DR Cameron, NE Heller, PR Huber, CA Schloss, JH Thorne, and AM Merenlender. 2018. New concepts, models, and assessments of climate-wise connectivity. Environmental Research Letters 13: 073002.
Peters RL and JDS Darling. 1985. Greenhouse effect and nature reserves: global warming would diminish biological diversity by causing extinctions among reserve species. BioScience 35: 707-717.
Heller NE and ES Zavaleta. 2009. Biodiversity management in the face of climate change: a review of 22 years of recommendations. Biological Conservation 142: 14-32.