Biofuels and invasive species risks: Assessing and managing risks through feedstock selection and cultivation strategies

Background/Question/Methods

The aviation community and others are pursuing biofuels for their potential greenhouse gas emissions benefits among other reasons. To maximize productivity, avoid food‐fuel conflicts and minimize greenhouse gas emissions, biofuel feedstocks are being selected based on traits that also enhance potential invasiveness.  These enhancements, include, but are not limited to, high biomass and/or seed production, tolerance of marginal cultivation conditions, and short generation times. This study investigates how voluntary codes, regulatory frameworks, and other current policies relevant to crop selection, cultivation, and/or biofuel production have integrated scientific knowledge of invasive species predictors, and to what extent those policies are being applied to avoid or minimize the invasion risk from biofuel production. This study also summarizes existing Weed Risk Assessments for a selection of biofuel feedstocks and compares the species’ eligibility for regulation under a variety of relevant policies and requirements.

Results/Conclusions

A large and growing body of work identifies ecological factors associated with invasion and integrates these factors into predictive weed risk assessment tools. These predictive methodologies can be used to select biofuel feedstocks that present low invasion risk, but this information has not been universally adopted. Voluntary best practices created by IUCN and the Roundtable on Sustainable Biofuels call for producers to avoid potentially invasive feedstocks and to use cultivation methods to reduce invasion risk. However, programs administered by federal and state agencies do not consistently follow these principles. A patchwork of regulations and incentive programs mitigate invasive species risks by influencing or limiting feedstock selection (including the use of genetically engineered cultivars) and by requiring producers to follow certain cultivation techniques or meet financial assurance requirements. Some feedstocks are noxious weeds subject to specific import and cultivation restrictions, but other species are unregulated or, in some cases, qualify for production incentives despite high potential for invasion.  Cultivation requirements are similarly inconsistent; risk mitigation requirements may be required at the state level or for products of genetic engineering, but are not required for all feedstocks with high invasion risk, nor is it always clear which species are ineligible in cases where incentive programs specify the avoidance of potential invaders.  We conclude that government agencies and producers are unevenly and inconsistently applying scientific information on invasion and that development of a more coordinated approach to feedstock selection and cultivation can greatly reduce the risk that biofuel development will result in the introduction or spread of invasive species in the United States.