In this paper, we evaluate the relations between land-use and socio-economic metabolism and particularly, socio-economic biomass flows, by constructing four scenarios for Austria in 2020. The scenarios were established using a biomass-flow model for Austria which was developed for this analysis. The model distinguishes between 15 different kinds of land use and relates demand for biomass in Austria to biomass production in Austria, considering imports and exports as well as biomass conversions in industrial processing and in livestock. We discuss four scenarios: (1) a trend scenario, based upon an extrapolation of current trends; (2) a scenario assuming the far-reaching liberalization of agricultural markets; (3) a scenario in which biomass utilization for energy and industry is maximized; and (4) a scenario based upon the approach of ‘‘cascade utilization'' of biomass. We find that increasing the use of biomass as an energy source might have considerable unwanted ecological effects including, among others, a reduction in the functioning of forests as a terrestrial carbon sink.