The sixth framework programme (FP6) of the European Commission funded several large scale and interdisciplinary projects such as SENSOR, EFORWOOD, and SEAMLESS to develop science-based methods for impact assessment. These projects brought together scientific expertise from all over Europe by involving numerous research institutes and universities. Given this stated preference of the European Commission for the development of decision support tools and the competitive application process prior to the commencing of the projects, it can be assumed that these tools represent the state of the art of contemporary science in the field of land use policy analysis and assessment. The three mentioned Integrated Projects developed tools for ex ante Sustainability Impact Assessment to support decision-making on policies related to multifunctional land use in European regions by combining the experience and expertise of various domains of science, such as land use, environmental economics, socio-economics and landscape research. The newly developed methods and tools have to handle large and heterogeneous data sets and cover a wide range of possible applications, especially in the field of regional development in rural areas.

This Special Issue consists of eight papers dealing with approaches developed in these large integrated projects and several smaller projects, all related to ex ante impact assessment of (socio)-economic and environmental research questions in the context of current European and international policy challenges in agriculture. These papers reflect the current state of European research related to innovative initiatives to develop model-based approaches for sustainability impact assessment and were presented during the international conference “Impact Assessment of Land Use Changes” (IALUC) organized by the EU project SENSOR held in Berlin, 7–9 April, 2009.

The first group of papers provides an overview of advanced methods of integrated approaches to assess agricultural and other land uses. Uthes et al. (2010) compare three integrated assessment tools developed by the EU projects SENSOR, SEAMLESS and MEA-SCOPE and discuss the policy relevance of these tools from the perspective of operational policy decision support with a focus on agricultural policies. Van Delden et al. (2010) present and discuss the experiences of the LUMOCAP project, which developed an integrated modelling approach to evaluate land use changes and their impact on the rural landscape of the European Union under the influence of the Common Agricultural Policy (CAP). Verweij et al. (2010) discuss, from an IT perspective, the development of the Sustainability Impact Assessment Tool (SIAT) by the project SENSOR, describe relevant software components and highlight the advantages of and the challenges in integrated environmental modelling in the future.

The second group of papers contains applications of quantitative modelling and heuristic approaches to conduct global impact assessments. Hermans et al. (2010) describe an explorative scenario of the European crop production in a liberalised world without European Union (EU) market interventions. The results form a plausible and salient thought-experiment of a possible future based on the consistent integration of current conceptual and quantitative models. Future scenarios for climate, demography, technology and global demand for agricultural commodities are used to assess the competitiveness of European agriculture. The method is illustrated for the 27 EU member state countries for three commodities. Lotze-Campen et al. (2010) present scenarios of global bio-energy production on the basis of a bio-economic modelling approach with a special focus on spatially explicit land and water constraints as well as technological change in agricultural production. They show trade-offs between agricultural expansion, intensification and trade.

Finally, the third group of papers describes experiences at the policy–science interface and research-based methods focusing on the forest value chains. (Lindner et al., 2002) and (Lindner et al., 2010) present the new software tool ToSIA that has been developed for assessing sustainability impacts of Forest-Wood Chains in the context of EFORWOOD. ToSIA enables to assess sustainability impacts in the forestry sector as affected, e.g. by changes in policies, market conditions, or technology. The paper discusses strengths and limitations of the approach and provides an outlook on further development perspectives of the methodology. von Geibler et al. (2010) present a methodological approach for the participatory development of value-chain wide sustainability indicator sets and their integration into a decision support tool. Special attention is given to the integration of stakeholder perspectives. Palosuo et al. test and demonstrate the ToSIA tool with an example Forest-Wood-Chain from Scandinavia that included furniture and bio-energy production. Exemplary indicators representing the three pillars of the sustainability were chosen to demonstrate and discuss the procedure: production costs, employment and transport intensity.