GIS tools for connectivity, corridor, or habitat modeling
While CorridorDesigner provides one method of modeling wildlife corridors with ArcGIS, it’s not the only game in town. Here are some other free tools you may find handy for modeling wildlife or ecological corridors, connectivity, or habitat. For updates on connectivity and corridors in peer-reviewed literature and the news, make sure to check out Conservation Corridor.
Connectivity and corridor GIS tools
Linkage Mapper is a GIS tool designed to support regional wildlife habitat connectivity analyses. Linkage Mapper uses GIS maps of core habitat areas and resistances to identify and map linkages between core areas. Each cell in a resistance map is attributed with a value reflecting the energetic cost, difficulty, or mortality risk of moving across that cell. Resistance values are typically determined by cell characteristics, such as land cover or housing density, combined with species-specific landscape resistance models. As animals move away from specific core areas, cost-weighted distance analyses produce maps of total movement resistance accumulated.
Circuitscape is a stand-alone Python program which borrows algorithms from circuit theory to predict patterns of movement, gene flow, and genetic differentiation among populations in heterogeneous landscapes. It uses raster habitat maps as input, and predicts connectivity and movement patterns between user-defined points on the landscape. Circuitscape is distributed by Brad McRae of the National Center for Ecological Analysis and Synthesis (NCEAS) at University of California, Santa Barbara.
CONNECTIVITY ANALYSIS TOOLKIT
The Connectivity Analysis Toolkit provides conservation planners with newly-developed tools for both linkage mapping and landscape-level ‘centrality’ analysis. Centrality refers to a group of landscape metrics that rank the importance of sites as gatekeepers for flow across a landscape network. The Toolkit allows users to develop and compare three contrasting centrality metrics based on input data representing habitat suitability or permeability, in order to determine which areas, across the landscape as a whole, would be priorities for conservation measures that might facilitate connectivity and dispersal. The Toolkit also allows application of these approaches to the more common question of mapping the best habitat linkages between a source and a target patch.
Conefor Sensinode quantifies the importance of habitat areas for the maintenance or improvement of landscape connectivity. It is conceived as a tool for decision-making support in landscape planning and habitat conservation, through the identification and prioritization of critical sites for ecological connectivity.
CONNECT – LANDSCAPE CONNECTIVITY MODELING TOOLBOX
Connect is a set of tools that helps researchers and conservation planners model landscape connectivity for multiple wildlife species in complex heterogeneous landscapes. Connect also allows users to combine single-species models of animal movement to identify areas of the landscape that facilitate the movement of multiple species. Connect packages Circuitscape, NetworkX, and Zonation into a user-friendly geoprocessing toolbox for ESRI ArcGIS 9.3.
UNICOR – UNIVERSAL CORRIDOR NETWORK SIMULATOR
UNICOR implements Dijkstra’s shortest path algorithm for any number of landscapes and distributions of species. The model’s features include a graphical user interface, parallel-processing, kernel path-buffering, connectivity maps, and various formatted outputs ready for graph and patch theory metrics.
FUNCONN – FUNCTIONAL CONNECTIVITY TOOLS
FunConn is a functional connectivity modeling toolbox for ArcGIS, distributed by Dave Theobald and the Natural Resource Ecology Laboratory at Colorado State University. The goal of the functional connectivity model is to allow landscape connectivity to be examined from a functional perspective. Functional connectivity recognizes that individuals, species or processes respond functionally (or behaviorally) to the physical structure of the landscape. From this perspective, landscape connectivity is specific to a landscape and species/individual/process under investigation.
Path Matrix is a tool for ArcView 3 to compute matrices of effective geographic distances among samples, based on a least-cost path algorithm. It was developed by Nicholas Ray of the Computational and Molecular Population Genetics Lab, University of Bern, Switzerland.
Habitat suitability and species occurrence modeling GIS tools
openModeller aims to provide a flexible, user friendly, cross-platform environment where the entire process of conducting a fundamental niche modeling experiment can be carried out. The software includes facilities for reading species occurrence and environmental data, selection of environmental layers on which the model should be based, creating a fundamental niche model and projecting the model into an environmental scenario.
StatMod is an extension for ArcView 3.3 that helps users create logistic regression and CART models using the statistical packages SAS and S-PLUS. It is distributed by Chris Garard of Utah State University.
Maxent provides a maximum-entropy approach for species habitat modeling. The software takes as input a set of layers or environmental variables (such as elevation, precipitation, etc.), as well as a set of georeferenced occurrence locations, and produces a model of the range of the given species. It is distributed by Princeton University.
BioMapper is a stand-alone package for developing ecological niche and habitat suitability models using only a species presence data. It is distributed by Alexandre Hirzel of the Laboratory For Conservation Biology, University of Lausanne, Switzerland.
DesktopGarp is a software package for biodiversity and ecologic research that allows the user to predict and analyze species distributions using presence data. The package is distributed by the University of Kansas Natural History Museum.
SPATIAL DATA MODELER
Spatial Data Modeler is a collection of geoprocessing tools for adding categorical maps with interval, ordinal, or ratio scale maps to produce a predictive map of where something of interest is likely to occur. The tools include the data-driven methods of Weights of Evidence, Logistic Regression, and two supervised and one unsupervised neural network methods, and a knowledge-driven method Fuzzy Logic.
PATCHMORPH PATCH DELINEATION TOOL
PatchMorph is an extension for ArcMap which delineates habitat patches from a habitat suitability or land cover map.
Reserve and protected area GIS tools
Marxan delivers decision support for reserve system design. Marxan finds reasonably efficient solutions to the problem of selecting a system of spatially cohesive sites that meet a suite of biodiversity targets.
Zonation identifies areas important for retaining habitat quality and connectivity for multiple species, indirectly aiming at species’ long-term persistence. The computational strategy of Zonation can be characterized as maximal retention of weighted, range size normalized (rarity corrected) richness. Zonation produces a complementarity-based priority ranking.
PANDA is a stand-alone application developed to provide a user friendly framework for systematic protected areas network design to ArcGIS users. Through the use of P.A.N.D.A. the designer can explore different hypothetical configurations of a system of protected areas in the planning area.
CLUZ is an ArcView GIS interface that allows users to design protected area networks and conservation landscapes. It can be used for on-screen planning and also acts as a link for the MARXAN conservation planning software. It is currently being developed at DICE and is funded by the British Government through their Darwin Initiative for the Survival of Species.
LINK is a set of ArcGIS tools designed to analyze habitat patterns across a landscape. LINK uses species habitat matrices to model potential species habitat and habitat diversity. What sets LINK apart from its predecessors is that it uses raster data sources—raster data sources allow LINK to model habitat over a much larger area than its vector based ancestors.
General GIS tools
Jenness Enterprises has created many extensions for ArcView 3.3 useful to ecological applications. Jeff Jenness created the CorridorDesigner ArcMap extension.
Hawth’s Analysis Tools is an extension for ArcGIS (specifically ArcMap). It is designed to perform spatial analysis and functions that cannot be conveniently accomplished with out-of-the-box ArcGIS. Most of these analysis tools have been written within the context of ecological applications such as movement analysis, resource selection, predator prey interactions and trophic cascades.