Scale

The paper describes an approach to landscape design that focuses on integrating bioenergy production with their components of environmental, social and economic systems. Landscape design as used here refers to a spatially explicit, collaborative plan for management of landscapes and supply chains. Landscape design can involve multiple scales and build on existing practices to reduce costs or enhance services. Appropriately applied to a specific context, landscape design can help people assess trade-offs when making choices about locations, types of feedstock, transport, refining and distribution of bioenergy products and services. The approach includes performance monitoring and reporting along the bioenergy supply chain. Examples of landscape design applied to bioenergy production systems are presented. Barriers to implementation of landscape design include high costs ,the need to consider diverse land-management objectives from a wide array of stakeholders, up-front planning requirements, and the complexity and level of effort needed for successful stakeholder involvement. A landscape design process maybe stymied by insufficient data or participation. An impetus for coordination is critical, and incentives may be required to engage landowners and the private sector. Hence devising and implementing landscape designs for more sustainable outcomes require clear communication of environmental, social, and economic opportunities and concerns.</p>

This paper connects the science of sustainability theory with applied aspects of sustainability deployment. A suite of 35 sustainability indicators spanning six environmental, three economic, and three social categories has been proposed for comparing the sustainability of bioenergy production systems across different feedstock types and locations.   A recent demonstration-scale switchgrass-to-ethanol production system located in East Tennessee is used to assess the availability of sustainability indicator data and associated measurements for the feedstock production and logistics portions of the biofuel supply chain.  Knowledge pertaining to the available indicators is distributed within a hierarchical decision tree framework to generate an assessment of the overall sustainability of this no-till switchgrass production system relative to two alternative business-as-usual scenarios of unmanaged pasture and tilled corn production.  The relative contributions of the social, economic and environmental information are determined for the overall trajectory of this bioenergy system’s sustainability under each scenario.  Within this East Tennessee context, switchgrass production shows potential for improving environmental and social sustainability trajectories without adverse economic impacts, thereby leading to potential for overall enhancement in sustainability within this local agricultural system.  Given the early stages of cellulosic ethanol production, it is currently difficult to determine quantitative values for all 35 sustainability indicators across the entire biofuel supply chain.  This case study demonstrates that integration of qualitative sustainability indicator ratings may increase holistic understanding of a bioenergy system in the absence of complete information.

Defining and measuring sustainability of bioenergy systems are difficult because the systems are complex, the science is in early stages of development, and there is a need to generalize what are inherently contextspecific enterprises. These challenges, and the fact that decisions are being made now, create a need for improved communications among scientists as well as between scientists and decision makers. In order for scientists to provide information that is useful to decision makers, they need to come to an agreement on how to measure and report potential risks and benefits of diverse energy alternatives in a way that allows decision makers to compare options. Scientists also need to develop approaches that contribute information about problems and opportunities relevant to policy and decision making. The need for clear communication is especially important at this time when there is a plethora of scientific papers and reports and it is difficult for the public or decision makers to assess the merits of each analysis. We propose three communication guidelines for scientists whose work can contribute to decision making: (1) relationships between the question and the analytical approach should be clearly defined and make common sense; (2) the information should be presented in a manner that non-scientists can understand; and (3) the implications of methods, assumptions, and limitations should be clear. The scientists’ job is to analyze information to build a better understanding of environmental, cultural, and socioeconomic aspects of the sustainability of energy alternatives. The scientific process requires transparency, debate, review, and collaboration across disciplines and time. This paper serves as an introduction to the papers in the special issue on ‘‘Sustainability of Bioenergy Systems: Cradle to Grave’’ because scientific communication is essential to developing more sustainable energy systems. Together these four papers provide a framework under which the effects of bioenergy can be assessed and compared to other energy alternatives to foster sustainability.

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.

Agricultural sustainability considers the effects of farm activities on social, economic, and environmental conditions at local and regional scales. Adoption of more sustainable agricultural practices entails defining sustainability, developing easily measured indicators of sustainability, moving toward integrated agricultural systems, and offering incentives or imposing regulations to affect farmer behavior. Landscape ecology is an informative discipline in considering sustainability because it provides theory and methods for dealing with spatial heterogeneity, scaling, integration, and complexity. To move toward more sustainable agriculture, we propose adopting a systems perspective, recognizing spatial heterogeneity, integrating landscape-design principles and addressing the influences of context, such as the particular products and their distribution, policy background, stakeholder values, location, temporal influences, spatial scale, and baseline conditions. Topics that need further attention at local and regional scales include (1) protocols for quantifying material and energy flows; (2) standard specifications for management practices and corresponding effects; (3) incentives and disincentives for enhancing economic, environmental, and social conditions (including financial, regulatory and other behavioral motivations); (4) integrated landscape planning and management; (5) monitoring and assessment; (6) effects of societal demand; and (7) integrative policies for promoting agricultural sustainability.