Managing trade-offs in landscape restoration and revegetation projects

Abstract

Landscape restoration projects often have multiple and disparate conservation, resource enhancement and sometimes economic objectives, since projects that seek to meet more than one objective tend to be viewed more positively by funding agencies and the community. The degree to which there are tradeoffs among desired objectives is an important variable for decision-makers, yet this is rarely explicitly considered. In particular, the existence of ecological thresholds has important implications for decision-making at both the project level and the regional level. We develop a model of the possibilities and choices for an agency seeking to achieve two environmental objectives in a region through revegetation of a number of sites. A graphical model of the production possibilities sets for a single revegetation project is developed and different tradeoff relationships are discussed and illustrated. Then the model is used to demonstrate the possibilities for managing all such projects within a region. We show that where there are thresholds in the tradeoff relationship between two objectives, specialization (single- or dominant- objective projects) should be considered. This is illustrated using a case study in which revegetation is used to meet avian biodiversity and salinity mitigation objectives. We conclude that where there are sufficient scientific data, explicit consideration of different types of tradeoffs can assist in making decisions about the most efficient mix and type of projects to better achieve a range of objectives within a region.