From the past to the present, from census to the grid : a socio-ecological analysis of land-use intensity across multiple spatial and temporal scales
Supplying sufficient amounts of biomass to a growing and prospering world population, while avoiding natural depletion, is a key challenge of the 21st century. From a production side perspective this will likely entail the intensification of current agricultural lands. However, many uncertainties relate to potentials of harvest increases and associated environmental trade-offs, particularly at the global scale. In this thesis I apply a consistent socio-ecological perspective on land systems that allows addressing three interrelated and virulent knowledge gaps: (a) Detecting current global patterns of land-use intensity through integrating socio-economic costs and benefits with changes at the land system level; (b) identifying regions with the highest (sustainable) intensification potentials and (c) tracing past land system trajectories in order to identify socio-economic and natural framework conditions under which changes in land-use intensity occur. Results on long term land system trends in Europe reveal surprising similarities between the most heterogeneous political and biophysical regions over the past 150 years. Land-use intensification was a somewhat universal trajectory on croplands in Europe, whereas trends on grasslands and forests were highly diverse, owing to economic and natural particularities. However, in a global perspective, cropland use intensity around 2000 differed substantially in terms of associated costs and benefits across biophysical regions. Improving global input efficiency could substantially reduce environmental burdens in high-input regions, such as many European countries and Eastern Asia, and raise biomass outputs by ca. 30% in the one quarter of croplands that are under low land-use intensity. This thesis contributes to land-use intensity research, both in a conceptual and empirical way. The holistic perspective on land use across various spatial and temporal dimensions allowed for insights into archetypical patterns of intensification, including related costs, benefits and ...