In order to stimulate conservation in agricultural landscapes programmes have been developed (e.g. in the context of agri-environmental schemes) with which farmers are compensated for carrying out agricultural activities in a biodiversity-enhancing manner. An important requirement for the design of such programmes is that they are cost-effective, i.e. that for existing financial resources the conservation output is maximised. The aim of the SOKO Bio project is to develop a software-based decision support tool based on an ecological-economic modelling procedure to design cost-effective compensation payments for measures to conserve endangered grassland species in the German Federal States of Saxony and Schleswig-Holstein. The software shall be able to (I) estimate the effects of selected measures on endangered grassland species in the two federal states for varying budgets, (II) estimate the cost-effectiveness of existing or planned compensation programmes and (III) define management objective functions (e.g. survival probability of various selected species) and maximise them for selected budgets. The software shall be easily adaptable to changing economic and ecological circumstances (e.g. climate change).