A guide to assess and value ecosystem services of grasslands

Abstract Comprehensive mapping of Ecosystem Services (ES) is necessary to understand the impact of global change on crucial ES and to find strategies to sustain human wellbeing. Economic valuation of ES further translates their biophysical values into monetary values, which are then comparable across different ES and easily understandable to decision makers. However, a comprehensive synthesis of methods to measure ES indicators in grasslands, a central element of many landscapes around the globe, is still lacking, hampering the implementation of grassland ES-multifunctionality surveys. To identify suitable and recommendable methods, we reviewed the literature and evaluated labor intensiveness, equipment costs and predictive power of all methods. To facilitate the translation of biophysical ES into monetary terms, we further provide an overview of available methods for the economic valuation of ES. This review resulted in a toolbox comprising 85 plot-scale methods for assessing 29 different ES indicators for 21 provisioning, regulating, supporting or cultural ES. The available methods to measure ES indicators vary widely in labor intensiveness, costs, and predictive power. Based on this synthesis, we recommend 1) to choose direct over indirect methods and ES indicators, 2) to use the most accurate methods to estimate ES indicators, 3) to take into account that one ES indicator can have implications for more than one final ES, and 4) to utilize the wealth of available methods and indicators to assess as many ES for ES-multifunctionality studies as possible, especially including cultural ES. Moreover, the overview of approaches that can be used for the economic valuation of different grassland ES shall facilitate economic ES-multifunctionality assessments. Thus, this methodological guidance will considerably support researchers and stakeholders in setting up ES comprehensive assessments and monitoring schemes in grasslands and shall ultimately help overcome incomplete or superficial surveys based on single or few ES only.