Ascertainment and Assessment of ES

The need for applications and tools of the—frequently mainly conceptually used—ecosystem service (ES) ideas has become more and more obvious during the last years. Practical applications are necessary to further develop and improve the conceptual base of ES on the one hand. On the other, tools for environmental and resource management are needed in order to further establish ES in decision making processes. The recognition and the appropriate quantification of ES are fundamentals for their valuation, independently whether the valuation is conducted with biophysical, social or economic methods. Their application and integration is one of the biggest challenges of contemporary ecosystem service science.