Effects of human land use on climate connectivity in North America

This page provides links to several datasets that were generated for and presented in Parks et al. (2020) (citation below). Climate connectivity—the ability of a landscape to promote or hinder species movement when responding to a changing climate—is contingent on multiple factors including the distance organisms need to move to ameliorate climate change and the resistance they experience along their movement routes. The authors of this study evaluated the influence of human land uses on climate connectivity across North America by comparing two climate connectivity scenarios, one considering climate change in isolation (the ‘climate scenario’) and the other considering climate change and human land uses (the ‘climate-HMG scenario’) (HMG: human modification gradient). Climate velocity and climate exposure were produced for each scenario (figs. 1 and 2, respectively). The authors also introduced a novel metric of climate connectivity, ‘human exposure’, that quantifies the cumulative exposure to human land-uses that organisms may encounter as they shift their ranges in response to climate change. Lastly, the authors produced ‘climate corridor’ maps that depict areas of high importance for facilitating range shifts under climate change (fig. 4). Please see metadata for additional information.

Please cite the data as:

 

Parks SA, Carroll C, Dobrowski SZ, Allred BW (2020). Human land uses reduce climate connectivity across North America. Global Change Biology. https://doi.org/10.1111/gcb.15009.


Figure 1

Figure 1. Climate velocity for North America for the climate scenario (a). The difference (km/year) between the climate velocity of the climate‐HMG scenario and the climate scenario (b). The ratio of climate velocity of the climate–HMG scenario to the climate scenario (c). Black indicates disappearing climates. HMG, human modification gradient.

Figure 2

Figure 2. Climate exposure (CE) for North America for the climate scenario (a). The difference in climate exposure between the climate‐HMG scenario and the climate scenario (b). Black indicates disappearing climates. HMG, human modification gradient; PCA, principal component analysis.

Scenarios

The authors developed two scenarios to evaluate the anthropogenic influence on climate connectivity: the climate scenario and the climate–HMG scenario.

    

Climate scenario: Analogs are defined as being climatically similar to the source pixel. The individual analog (i.e. pixel) that minimized exposure to dissimilar climates was identified using least-cost path modelling and a resistance surface based on climatic dissimilarity from each source pixel. This is the null model (i.e. no influence from human land uses) which we compare to the climate–HMG scenario. 

    

Climate-HMG scenario: Analogs are defined as being climatically similar to each source pixel and have HMG values that are less than or equal to each source pixel. The individual analog (i.e. pixel) that minimized exposure was identified using least-cost path modelling and a resistance surface based on both climatic dissimilarity and the HMG.


Reference period climate represents averages from 1981 to 2010; late‐century climate represents 2071–2100 and were generated from a multi‐model ensemble of 15 CMIP5 GCMs under RCP 8.5. Climate datasets were obtained from AdaptWest (https://adaptwest.databasin.org/).


Figure 3


Figure 3. Maps depict climate corridor scores for the climate scenario (a, c) and the climate-HMG scenario (b, d). Climate corridors (qualitatively represented by locally high climate corridor scores) are more diffuse and linear in the climate scenario compared to the more convergent and circuitous corridors in climate–HMG scenario, the latter of which accounts for the HMG. The two regions depicted contrast in both topography and human land-use intensity: panels (a) and (b) show a region of North America that is fairly topographically complex and, for the most part, has low HMG values, whereas panels (c) and (d) show a region that is relatively flat but has high HMG values.


Data Products

Data archive (15 MB)


There are seven gridded datasets contained in the zip file linked above:

1.      Climate velocity for the climate scenario

2.      Climate velocity for the climate-HMG scenario

3.      Climate exposure for the climate scenario

4.      Climate exposure for the climate-HMG scenario

5.      Human exposure for the climate scenario

6.      Climate corridors for the climate scenario

7.      Climate corridors for the climate-HMG scenario.