System approach for evaluating the potential yield and plantation of Jatropha curcas L. on a global scale.

Many Jatropha curcas Linnaeus (JCL) plantations have been established in tropical and subtropical regions worldwide. To assess the potential of JCL for biofuel production, the potential areas for JCL plantations, and the yields of JCL must be estimated as accurately as possible. Here, we present a system approach to estimate JCL yields, classify yield levels, and estimate productivity of future JCL plantations. We used a process-based net primary productivity (NPP) model to estimate potential JCL yields. The model estimated that the potential yield of JCL dry seed will vary from 0 to 7.62 ton ha(-1) y(-1), in contrast to estimates of 1.50-7.80 ton ha(-1) y(-1) from previous assessments. We formulated a zoning scheme that takes into account land cover status and potential yield levels. This scheme was used to evaluate the potential area and production of future plantations at the global, regional, and national levels. The estimated potential area of JCL plantations is 59-1486 million hectares worldwide, and the potential production is 56-3613 million ton dry seed y(-1). This study provides scientific information on global patterns of potential plantation areas and yields, which can be used to support bioenergy policy makers to plan commercial-scale JCL plantations.