This study analyses the economic effects of the storm Lothar in the Swiss forests. A method is developed to quantify the aggregated effects of Lothar on the income (flow) and assets (stock) of the forest sector. The method is based on a comparative approach (before - after) and on an infinite rotation forest model. Scenario and sensitivity analyses show, how different strategies of coping with the effects of a storm and different assumptions concerning further variables (e.g. damages, prices, rate of discount) affect the income and asset effects. The overall economic relevance of the storm is qualitatively assessed. Additionally, the potentially affected groups are identified in a systems analysis. Different effects dependent on different coping strategies are discussed, with respect to the type, direction and order of magnitude of the effects. Conclusions for required political action are deduced from the synthesis and interpretation of the results.