An interdisciplinary tool for monitoring conservation impacts in Madagascar

Integrated conservation and development programs (ICDPs) are large, complex experiments in managing natural resources for both biodiversity and economic benefits. Monitoring should be an essential element within these programs to provide information for assessment and adaptive management; however, selecting appropriate indicators and designing effective monitoring programs is difficult due to thier complesity. Useful native plants can make excellent indicator species for ICDPs because monitoring them provides information simultaneously on both ecological and socioeconomic change. In addition, monitoring useful species is necessary for establishing management plans for their sustainable use. On the Masoala Peninsula in Madagascar, site of an ICDP, we conducted household surveys and developed new ethnobotanical indices from selecting the most important plant species in different use categories from 105 forest products harvested destructively by local inhabitants. Unlike previous studies, use categories were defined non-arbitrarily as groups of substitution products (e.g., products that are equivalent in their specific usage. By comparing use and preference within groups of substitution products, it is possible to predict over-extraction of preferred species and resource switching to secondary species. Knowledge of substitution groups is thus a necessary prerequisite for selecting indicator species that will furnish early warnings of non-sustainable use. We identified 13 groups of substitution products covering the major household uses on Masoala. From these we selected the 25 species that were most heavily used or preferred. Following the use of these species over time will permit a detailed spatial and temporal analysis of change sin resource use patterns and harvesting impacts in response to the integrated conservation and development program ultimately allowing the test of the hypothesis that economic development linked to conservation promotes conservation.