1 Tahrcountry Musings: More on Wildlife Corridors

Wednesday, February 23, 2011

More on Wildlife Corridors

The other day I was discussing with my friend Ramesh the pros and cons of corridors. The paper Consequences and Costs of Conservation Corridors was a good starting point for our conversation.

Corridors could alleviate threats from inbreeding depression and demographic stochasticity. Some species require more resources than are available in single refuges. Here a network of refuges connected by corridors may allow persistence. Corridors in riparian forest may constitute an important habitat in its own right.
Now here come the negative impacts. They could transmit contagious diseases. They could be a causative factor for fires, and other catastrophes. They may increase exposure of animals to predation, domestic animals, and poachers. They could prove expensive in economic terms. The researchers say a bridge that would maintain a riparian corridor costs about 13 times as much per lane-mile as would a road that would sever the corridor. Per-unit-area management costs may be larger for corridors than for refuges. Here it may be cheaper to manage some species by moving individuals between refuges rather than by buying and maintaining corridors.
Adequate studies are indeed needed in the field before we recommend the type of corridor.  The researchers say right now a dearth of information on the degree to which different species use corridors makes it difficult to tell which of these potential advantages will be realized in any particular case. Each case must be judged on its own merits because species-environment interactions differ.
Consequences and Costs of Conservation Corridors
Article first published online: 21 APR 2005
DOI: 10.1111/j.1523-1739.1987.tb00010.x

Sometimes back I had posted an item titled “Tools for modeling wildlife corridors” in my other blog Highrangetidings.blogspot.com (I have discontinued this blog). Ramesh feels that this post needs to be posted here as he feels that it would be of use to the wildlife managers. So guys here it comes

The copyright for the entire description belong to corridordesign.org
Here is what is available at corridordesign.org.  They are best suited for designing corridors in a heterogenous landscape at a regional (e.g. 2 - 500 km long) scale.

CorridorDesigner  provides one method of modeling wildlife corridors with ArcGIS.

Here are some other free tools for modeling wildlife or ecological corridors, connectivity, or habitat.
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.
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.
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.
Formerly called ArcRstats, the HabMod/ConnMod toolboxes produce multivariate habitat prediction rasters using ArcGIS and the open-source R statistical package for implementing classification and regression (CART), generalized linear models (GLM) and generalized additive models (GAM), and includes a connectivity modeling toolbox. The toolbox is distributed by Pat Halpin and the Marine Geospatial Ecology Laboratory at Duke University
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.
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.
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.
GRASP (Generalized Regression and Spatial Prediction) is a package for the statistical softwares R and S-PLUS for creating predictive models of species distributions using Generalized Additive Models (GAMs). It is distributed by A. Lehmann, J.R. Leathwick and J.McC. Overton at the Landcare Research Institute, New Zealand.
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 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 is an extension for ArcMap which delineates habitat patches from a habitat suitability or land cover map.
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.
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.
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.

No comments: