Lessons on alien biofuel crops invasiveness risk assessment: based on practical experiences from Jatropha curcas L. in southern and western Africa.
Invasion by newly introduced species is considered the second largest global threat to biodiversity after habitat destruction. Biofuel crops are increasingly promoted as economic solutions to satisfy global energy needs and as an alternative means to fight climate change and reduce greenhouse gas emissions. Some studies have warned about the risk of biological invasions and environmental damage in tropical habitats as a consequence of land conversion to biofuel crops. Once species escape and become invasive, they can have detrimental social, economic, and ecological effects and can threaten the transition to adaptive rural development. In this context, there is a need to develop ways to select and manage biofuel crops as components of resilient agro-ecosystems that balance economic profits and ecosystem wellbeing in the changing climate. This would necessitate addressing several issues, including the main biological traits and environmental circumstances associated with invasive behavior, consequences of long-term biofuel plantations and other unintentional changes in the rural landscape, the question of accountability for invasions and the consequent ecological damage, and the management and policy interventions needed to prevent invasions and respond to them if they occur. In this chapter, we reviewed the ecological fundamentals of invasiveness by analyzing the plant traits that potentially lead to invasive behavior. We applied a predictive invasiveness risk assessment model to Jatropha curcas L., a tropical biofuel crop of which the sustainability is heavily debated, and compared the outcomes with the current status of knowledge on its invasiveness. Then we showed effective methodologies on how to assess the invasiveness risk of biofuel crops in the field, based on our field experiences from southern and western Africa.