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.
The chapter recommends carrying out risk assessments for exotic
biofuel crops, such as J. curcas and others, using an in situ field experimental
method, on top of predictive invasiveness risk evaluation
models, as part of procedures to regulate their use at the national
or local level. The advantage of the experimental approach is that it
generates knowledge and experience useful for farmers and local
communities in order to monitor, prevent, and manage potential
invasive crops, and integrate their use with the overall adaptive
rural development approach. Such an approach may be more successful
at avoiding bio-invasions and promoting sustainable biofuel
development in Africa.