GeoDesign Knowledge Portal

Resnet & Surrogacy

ResNet and Surrogacy are companion programs which respectively address the biodiversity reserve selection problems of using surrogate measures of biodiversity and of prioritizing places based on these measures.

Model Type

The general place-prioritization procedure of ResNet 1.2 was first outlined in the late 1980s. It presumes a given area that has been divided into cells (based perhaps on geographical coordinates or ecosystem boundaries), a record for every cell of the presence or absence of every defined species, and a definite target for representation, such as the minimum number of times any species must be represented by the selected cells. The main virtue of this package is computation speed. It is fast enough for use to generate new plans even with relatively large data sets during a planning meeting. The ResNet algorithms emphasize the selection of places containing rare species (the principle of rarity), and places which add as many under-represented species as possible to a set of selected places (the principle of complementarity). The ResNet algorithms are particularly pertinent to reserve designs for conservation of rare species. User control over composition of each selection set is determined by initialization options and other options such as area and cost constraints. Spatial solutions presented in ArcView provide a starting point for further planning considerations. ResNet has been systematically compared to SITES. The set of selected reserve elements are displayed in ArcView GIS. Incremental additions to the selected set, due to progressively relaxing area constraints for example, are easily displayed in a single view.

Developer Assistance Needed For Installation/Configuration

Justus, J. and S. Sarkar. 2002. “The Principle of Complementarity in the Design of Reserve Networks to Conserve Biodiversity: A Preliminary History,” Journal of Biosciences 27: 421 – 435. []Kelley, C.; Garson, J.; Aggarwal, A.; Sarkar, S. 2002. Place prioritization for biodiversity reserve network design: a comparison of the SITES and ResNet software packages for coverage and efficiency. Diversity and Distributions 8: 297-306. []

Indicators Used (No Longer Available)

Image File Name

Biodiversity Conservation

Ecosystem Management

Fish And Wildlife Management

Forest Management

Source Of Description

Reserve System

Site Search Or Selection

Glossary Display Property

Conservation Of Biodiversity

Decision Modeling

Land Use Allocation

Landscape Analysis And Modeling

Domain Knowledge Modeling Area

Alternative Generation

Rank Alternatives


Online Download Available

Optimization Methods

Systems Functional Components

Data Management

GIS Analysis Integration

GIS Display Integration


Information Source

Biophysical Process

For Application Domains

All (User Defined Analysis Extent)

Software Required

All (User Defined Unit Of Observation)


Species Diversity

Species Viability

Planning And Decision Process Phases/Steps Served


Decision Problem Types Targeted


Decision Problem Types Targeted

ResNet 1.2: Windows interface to computational engine (program 1.2).Program 1.2: computational engine for implementing the ResNet algorithm.ResNet.avx: ArcView 3.2 extension for viewing spatial solutions.Surrogacy1.1: Assists with selection of surrogate measures for biodiversity



Last Updated


Indicators Used


Model Type

Regularly Distributed


Biodiversity And Biocultural Conservation Laboratory, University Of Texas, Austin

Supports Analysis Of Interdisciplinary Interactions

National Commission On Science For Sustainable Forestry


Sahotra Sarkar

Decision Process Activity Types Served

Software Tools And Models - All

Spatial Decision Support Systems

Methods And Techniques Implemented


For Application Domains

Alternative Ranking, Decision Making

Decision Alternatives Generation, Scenario Simulation


Decision Process Activity Types Served

Spatial Decision Support Systems

Contact Person

Decision Model

Evaluative Models

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