Biofuels: the risks and dangers of introducing invasive species

Biofuel crops are increasingly promoted as environmental and economical solutions to global energy needs, but actual benefits versus costs may be less favorable than advocates claim. Among the risks associated with their cultivation is the potential to exacerbate the invasive species problem. Evidence is growing that many proposed biofuel crops are ideally suited to become successful invaders. We compared actual and candidate terrestrial biofuel crops suitable for temperate and tropical climates with introduced, nonbiofuel species, and demonstrated that biofuel species are almost three-times more likely to naturalize and over twice as likely to be invasive as nonbiofuel crops in both climatic conditions. Similar potential may exist for algae biofuels. The risks could be mitigated, and unintended environmental costs avoided, by implementing precautions including assessing and removing the worst invaders from consideration, selecting lower risk species for widespread cultivation, and actively controlling the spread of crops from cultivated areas.