Landscape implications of bioenergy feedstock choices are significant and depend on land-use practices and their environmental impacts. Although land-use changes and carbon emissions associated with bioenergy feedstock production are dynamic and complicated, lignocellulosic feedstocks may offer opportunities that enhance sustainability when compared to other transportation fuel alternatives. For bioenergy sustainability, major drivers and concerns revolve around energy security, food production, land productivity, soil carbon and erosion, greenhouse gas emissions, biodiversity, air quality, and water quantity and quality. The many implications of bioenergy feedstock choices require several indicators at multiple scales to provide a more complete accounting of effects. Ultimately, the long-term sustainability of bioenergy feedstock resources (as well as food supplies) throughout the world depends on land-use practices and landscape dynamics. Land-management decisions often invoke trade-offs among potential environmental effects and social and economic factors as well as future opportunities for resource use. The hypothesis being addressed in this paper is that sustainability of bioenergy feedstock production can be achieved via appropriately designed crop residue and perennial lignocellulosic systems. We find that decision makers need scientific advancements and adequate data that both provide quantitative and qualitative measures of the effects of bioenergy feedstock choices at different spatial and temporal scales and allow fair comparisons among available options for renewable liquid fuels.

Biorefineries refer to conversion operations where biomass feedstock is converted to multiple products such as chemicals, fuels, and bioproducts. The concept focuses on maximizing valued extractables while minimizing waste streams. A low cost collection and converting the biomass to feedstock is critical to the success of these emerging industries. A conservative estimate shows that demand for feedstock for biorefineries may reach 172 million dry tons over the next decade (2010) and more than 508 million dry tons in 2020 if biomass technology implementation achieves the stated goals. An orderly supply of this large amount of biomass to biorefineries requires new and robust equipment and well-established infrastructure. At the present, low and inconsistent demand for biomass for energy is the main reason for lack of interest on the part of manufacturers to invest in equipment development. It is important however, that research and development in production and supply technologies proceed in parallel with developments in conversion technologies. This paper reviews the operations involved in biomass supply and identifies three areas of research: moisture control, densification, and systems modeling as key areas of research. Other areas of work such as single step harvesting and on farm fractionation of biomass for added value purposes has also been identified as important areas of work. Manufacturers and processors need reliable engineering data on harvesting and handling of biomass in order to embark on improving and designing new equipment for biomass to feedstock operations.

The availability of biomass feedstocks' as well as efficient and cost-effective processing technology, are key determinants of the economic viability of obtaining fuel additives and oxygenated chemicals from biomass. This series of papers examines biomass feedstock availability, and the impact of advances in hydrolysis and pretreatment methods on improving extents of conversion of cellulose to glucose. Significant progress has been made, but the economic impact of these advances will not be fully realized or documented until the first biomass conversion plants are built. In the meantime, these papers provide insights into the developments which enhance the prospects for implementation.