Emergent properties of sustainability: Using agroecosystem indicators within spatial and temporal frameworks

This study reviews sustainability indicators for production of bioenergy crops and assesses the applicability of those indicators at diverse spatial and temporal extents. Various research groups from agricultural, urban development, life cycle assessment and bioenergy domains have generated extensive checklists of sustainability indicators, separating them into environmental, economic and social measurements. The applicability of those measurements depends not only on the crop type and the geographic region where the assessment is done, but also on the spatial resolution and time frame of the assessment. A detailed assessment of agronomic and environmental indicators is possible at a farm, field, or sub-field scale, but few social impact indicators can be measured at that resolution. County-level assessments can introduce additional social and economic impact variables, but can also make it difficult to discriminate field-level impacts like farm profitability or soil quality. Time introduces additional complexity since different measurements may be needed to assess daily, seasonal and multi-year effects. This study uses the example of farm landscape planning and decision support to illustrate such dimension-dependent choices of indicators. Results indicate that assessment boundaries with respect to space and time play a large role in evaluating agroecosystem sustainability. Recognition of those influences is important for improving stakeholder engagement, technical innovation, and policy support.