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32 <br /> and will be unable to move across areas that it cannot physically traverse(a barrier across or alongside a <br /> road). A particular least cost corridor will preferentially include any areas similar to the salamander's <br /> habitat(whether small or large) and will exclude movement barriers and minimize expanses of <br /> threatening or inhospitable habitat. Over time, a connected landscape of habitat patches and functional <br /> least cost corridors can promote successful movement of individuals between a network of populations <br /> (Gilbert-Norton et al. 2010),which ultimately supports long-term persistence,health, and resilience of <br /> species and ecosystems. <br /> (a) (b) Least cost path <br /> Habitat <br /> Patch A Habitat <br /> \ Patch B <br /> Least cost corridor <br /> Figure 8. (a)Depiction of a habitat-corridor network with <br /> habitat patches in dark green and corridors in light green <br /> (reproduced from Rudnick et al. 2012). (b) Two habitat <br /> patches connected by areas of lowest movement cost for a <br /> given species across a cost(or resistance)surface, defined by <br /> a threshold of maximum movement cost. <br /> To create the habitat-corridor network, Tuttle used ArcGIS 10.4(ESRI 2014),the GeoHAT Toolbox for <br /> ArcGIS (Geospatial Habitat Assessment Toolkit) (Fay 2012), customized ArcGIS models and Python <br /> scripts developed by Tuttle(unpublished), and NetworkX(software for network analysis using the Python <br /> programming language) (Hagberg et al. 2008). During the analysis process,the Technical Subcommittee <br /> (and later the Policy Subcommittee)reviewed data inputs and intermediate results and provided feedback <br /> in an iterative process of refining the data inputs,parameters, and analytical approach to best represent <br /> landscape habitat connectivity for the project area in the final results. <br /> Natural communities: species and habitats <br /> The project focuses on connectivity for preservation of terrestrial wildlife species(and many aquatic <br /> species by inclusion of riparian areas),natural communities, and existing conservation lands. Building on <br /> biodiversity and habitat assessments developed by NCWRC and NCNHP,the group elected to focus on <br /> priority species and natural communities (or habitat types)identified in the North Carolina Wildlife <br /> Action Plan(SGCN;NCWRC 2015) and in NCNHP's List of Rare Animal Species of North Carolina <br /> (Ratcliffe 2018). Hall's previous work on LHIGs(Hall 2008,2009, 2018)helped focus the project on the <br /> function and movement of several focal species groups (indicator guilds)within and between habitat <br /> types in a landscape network. In the LHIG framework, species are grouped into guilds by similar habitat <br /> needs and responses to habitat fragmentation and development. Because of their sensitivity to <br /> fragmentation,these indicator guilds can represent the conservation needs of many species that rely on <br /> these habitats or,put another way,that collectively embody these natural communities. Hall's work on <br /> LHIG for the Eastern Piedmont of NC (Hall 2008,2009,2018) informed the definition of priority habitats <br /> and species guilds for the project area, and the relationships between them. <br /> A Landscape Plan for Wildlife Habitat Connectivity 19 <br />