Assessing influence in biofuel production and ecosystem services when environmental changes affect plant–pest relationships

AbstractClimate change is currently affecting both biodiversity and human activities; land use change and greenhouse gas emissions are the main drivers. Many agricultural services are affected by the change, which in turn reflects on the basic provisioning services, which supply food, fibre and biofuels. Biofuels are getting increasing interest because of their sustainability potential. Jatropha curcas gained popularity as a biodiesel crop, due to its ease of cultivation even in harsh environmental conditions. Notwithstanding its high economic importance, few studies are available about its co‐occurrence with pests of the genus Aphthona in sub‐Saharan Africa, where these insects feed on J. curcas, leading to relevant economic losses. Using ecological niche modelling and GIS post‐modelling analyses, we infer the current and future suitable territories for both these taxa, delineating areas where J. curcas cultivations may occur without suffering the presence of Aphthona, in the context of future climate and land use changing. We introduce an area‐normalized index, the 'Potential‐Actual Cultivation Index', to better depict the ratio between the suitable areas shared both by the crop and its pest, and the number of actual cultivations, in a target country. Moreover, we find high economic losses (~−50%) both in terms of carbon sequestration and in biodiesel production when J. curcas co‐occur with the Aphthona cookei species group

The economics and greenhouse gas balance of land conversion to Jatropha: the case of Tanzania

Due to higher oil prices, abundance of labor and suitable land and its stable political climate, Tanzania attracted many investments in Jatropha. Although several studies on Jatropha's economic potential are available, its true economics are still uncertain. This paper aims to add to the growing body of knowledge on the socio-economic performance of the Jatropha system by (i) studying the economic potential (net present value - NPV) of the current most prevailing Jatropha system for Tanzanian farmers and its regional differences, by (ii) making a greenhouse gas (GHG) balance and its economic value of the Jatropha activities on regional level, and by (iii) calculating break-even thresholds for yield and seed price. Therefore, regional yield modeling, regional life-cycle assessment, and NPV calculations based on Monte Carlo simulations, each with its set of assumptions, are combined. This study shows positive economic potential of Jatropha cultivation in most of the Tanzanian regions. However, the results also show that 13 of 20 Tanzanian regions will not attain a net positive GHG balance within 10 years. This indicates that the environmental impacts might be more restrictive for Jatropha's sustainability potential in Tanzania than the socio-economic potential. These results are based on the combination of three models, which consists of strong interdisciplinary modeling work. However, this modeling also contains simplifications (e.g. no opportunity cost for 'marginal' land) and uncertainties (e.g. using globally modeled potential yield estimations), which have to be considered in the interpretation of the results.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Invasiveness risk of biofuel crops using Jatropha curcas L. as a model species

Biofuel crops are promoted as a climate friendly alternative to fossil energy. Yet environmental risks such as potential biodiversity loss are not always adequately considered. This might occur directly as a consequence of land-use change from natural systems to biofuel plantations, but also through invasive behavior of the biofuel species, as it might disperse and establish into adjacent natural systems. Therefore, there is a need to perform ex-ante invasiveness risk assessments including field trials on new biofuel species before they get promoted and expanded on a large scale. This perspective uses Jatropha curcas L. as a model biofuel crop and reviews the biological traits and the circumstantial factors which may contribute to its invasive behavior. J. curcas has recently received much attention as a biodiesel 'wonder crop' and is being planted at large scale without scientific study on its invasiveness risk. We applied two risk assessment frameworks to provide an ex-ante invasiveness risk assessment and obtained that J. curcas is a species with a high invasiveness risk, which is in contradiction with recent experimental evidence. We discuss the limitations of the available risk assessment frameworks, which may have led to unreliable prediction. We interpret the outcome of this theoretical exercise with some recommendations for the selection, introduction, cultivation, and processing stages of J. curcas and other biofuel crops to minimize invasiveness risk. Finally we point to the responsibilities of investors and governments and the need for integrated research of the whole biofuel production supply chain to avoid bio-invasions. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd.FLWNAinfo:eu-repo/semantics/publishe