Omnidirectional Connectivity for Resilient Terrestrial Landscapes in the Pacific Northwest

This broad-scale (up to 50km) landscape connectivity analysis, identifies areas likely to facilitate ecological flow—particularly movement, dispersal, gene flow, and distributional range shifts for terrestrial plants and animals—over large distances and long time periods.  Similar to the local permeability analyses (3km radius, Buttrick et al. 2015), this analysis is not species-specific. Rather, it focuses on structural connectivity of natural lands, with resistance to movement modeled as a function of landscape naturalness. This map does not incorporate projections of future climates, nor does it address connectivity for aquatic species. The results identify broad, intact areas where movement of terrestrial organisms is largely unrestricted by human modifications to the landscape, as well as constricted areas where fragmentation has reduced movement options and further habitat loss could isolate remaining natural lands.
 
This map represents OmniScape current flow normalized by regional flow potential. Regional Flow Potential indicates how much current flow would be expected in the absence of barriers, and is proportional to the amount of natural land within the focal window. Upper and lower extremes of regional flow potential are overlaid in this map in order to highlight areas with the most and least natural land to connect, respectively. This helps to distinguish 1) broad, intact areas where movement is diffuse or largely unrestricted, 2) channeled areas or pinch points where further habitat loss could isolate natural areas, and 3) areas where flow is impeded by barriers. 
 
OmniScape, a moving window implementation of CircuitScape, represents a landscape as a resistive surface. Landscape features conducive to movement are given low resistances, and features that act as barriers to movement are given higher resistances. Similarly, a source weight surface is constructed with greater source weights assigned to pixels in more natural condition. OmniScape utilizes these surfaces to model the current flow between all semi-natural lands in the focal window, with higher current flow occurring between areas with high source weights and along paths of low resistance.  More details are available from McRae et al. 2016.
 
These data are part of a land facet terrestrial resilience project created for the Pacific Northwest to identify the most resilient terrestrial sites in the Northwest U.S. that will collectively and individually best sustain native biodiversity even as the changing climate alters current distribution patterns. The central idea is that by mapping key geophysical features and evaluating them for landscape characteristics that buffer against the effects of climate change, we can identify the most resilient places in order to guide future conservation investments.  All the datasets, along with the full report containing methods and maps are available at:  http://nature.org/resilienceNW
See a gallery of all datasets from the Conserving Nature’s Stage project on Data Basin:http://nplcc.databasin.org/galleries/e41a3ea84e78463bbf9f03ce2f8e9205