How can we estimate buffer zones of protected areas? A proposal using biological data

Abstract

A strategy to avoid the loss of habitats and preserve large areas is the establishment of protected areas. Brazil's Conservation Units National System (SNUC) determines that protected areas should be surrounded by buffer zones where human activity is restrict, but the established size of the buffer seems arbitrary. The restrictions provided by SNUC could be based on limits that allow the persistence of species' ecological function. Here we use the "landscape species" concept as a tool for buffer zone design, using the marsupial Micoureus paraguayanus as a model organism. We used its minimum area requirement for population viability (5,000 ha) to define the size of buffer zones around protected areas with smaller size that the minimum required area. The amount of habitat within protected areas was negatively correlated with the buffer size. Therefore, the largest the protected area, the smaller should be its buffer zone, provided that it does not have an impermeable barrier. Buffer zones are generally in private properties and, therefore, governmental incentives are essential to stimulate land uses compatible with biological flux through a permeable matrix. The method proposed here provides a simple analysis that can be used to establish the limits of buffer zones. © 2010 ABECO.