Sites: An Analytical Toolbox for Ecoregional Conservation Planning

Link to project overview
Download toolbox package
View slideshow of example
Link to TNC Homepage
Link to UCSB Biogeography Lab
UCSB Biogeography Lab
Principal Investigator:
Dr. Frank Davis

Dr. Sandy Andelman
Dr. David Stoms



The Nature Conservancy (TNC) recently initiated a new program of ecoregion-based conservation.  This program aims to increase the efficiency and effectiveness of TNC's conservation activities through a systematic approach to regional portfolio assembly coupled to local, on-the-ground implementation.

In 1998, TNC funded a project at UCSB to:

  • Develop a new reserve siting tool for regional conservation analysis that explicitly incorporates spatial design criteria into the site selection process.
  • Test and apply the new planning approach and performance measures in a structured decision process involving local TNC staff to develop hypothetical conservation portfolios in two different ecoregions.
  • Produce a web-based tutorial, including worked examples using TNC data and ecoregions; and conduct a training workshop for TNC staff interested in learning and applying the regional conservation planning tools to other TNC regions.
Sites 1.0 is a customized ArcView project that facilitates designing and analyzing alternative portfolios.  The software in Sites 1.0 to select regionally representative systems of nature reserves for the conservation of biodiversity is called the Site Selection Module (SSM).  It is a streamlined derivative of SPEXAN 3.0 (Spatially Explicit Annealing) that was developed by Ian Ball and Hugh Possingham.  SPEXAN was originally developed as a stand-alone program with no GIS interface for displaying portfolios and ancillary spatial data.  The model was applied in two TNC ecoregions--the Idaho Batholith and the Northern Sierra Nevada.  This web site contains the Sites 1.0 software, example data sets, and a slide show demonstrating the modeling process.