The production of biobased feedstocks (i.e., plant- or algal-based material used for transportation fuels, heat, power and bioproducts) for bioenergy production has been expanding rapidly in recent years. Unfortunately, there are considerable knowledge gaps relative to implications of this industry expansion for wildlife. This information deficit is likely to grow as the industry expands and rapidly evolves in new directions in the coming years. Although current liquid fuels are produced nearly entirely from sugars – mainly from corn, sorghum and sugar cane; and from oils – mainly soy and camelina, the next generation of biofuels is expected to be based on cellulosic materials from perennial grasses and trees, and from oils produced from micro-crops such as algae and aquatic plants. Nearly all of the feedstocks currently in use or proposed for use can be used for liquid transportation fuel, solid fuel to produce heat and/or power, or for biobased products such as plant-based plastics, textiles, and pharmaceuticals.
This technical review focuses on the current state of knowledge about effects of growing, managing, and harvesting feedstocks for bioenergy on wildlife and wildlife habitat – the portion of the bioenergy supply chain that will likely have the greatest direct and indirect effects on wildlife and wildlife habitat (Fig. 1). It is most likely that effects will fluctuate greatly from site to site depending on a common list of variables. To determine possible wildlife impacts, a site manager needs to consider a number of questions and scenarios. Some of those include: What bioenergy crop is being produced? Is it replacing natural vegetation as a dedicated energy crop? Does it result in a land use change? How productive was the site to start with in terms of fertility, growing season, and moisture? How intensively and with what inputs is it being managed for production? How much of the landscape will be occupied by the feedstock? Does it complement, improve, change, or eliminate current or projected future wildlife habitat? How much, how often, and when will it be harvested? What type of habitat structure may be provided (or eliminated) by this feedstock? Are managers willing to trade some production potential for wildlife habitat conservation? What is the potential to maintain elements of habitat structure (e.g., snags, buffers, etc.) on the landscape? What wildlife species and communities are currently occupying the site and what do they need to survive? What wildlife species or suites of species are considered desirable or undesirable on the site? Are any of the species or communities of conservation concern, especially protected species and imperiled ecosystems? How do the quantity, composition, and configuration of available onsite and surrounding habitat types affect wildlife use and survival?
Throughout this publication, the authors have tried to provide information that answers these questions so that site managers might better predict consequences of managing bioenergy feedstocks. Unfortunately, very little research has been done that specifically addresses the impact of bioenergy production on wildlife habitat. That, combined with bioenergy companies continuous search and development of new feedstocks, makes developing specific recommendations difficult at this time. However, general guidelines exist for qualitatively assessing value of different crop types and management practices on wildlife and associated habitat (Fig. 2; Tables 2 and 3; Appendix A). Efforts have been made to provide links to best management practices and renewable fuel standards throughout the document so the user can research the information more completely as needed.
Demand for bioenergy will continue to increase as human populations expand and wildlife continues to feel the pressures of competing interests. Research on wildlife effects from bioenergy production is limited. We hope that this technical review will expose areas in need of additional attention and encourage stakeholders to continue pursuing knowledge for the sake of our wildlife resources.