Ecosystem services assessment tool for agroforestry (ESAT-A): An approach to assess selected ecosystem services provided by alley cropping systems

The realization that ecosystem services (ES) are in decline prompted endeavors to quantify them in an attempt to secure ES provision while rewarding ES suppliers. Quantifying ES is expected to enhance the implementation of sustainable land use systems, like alley cropping systems for woody biomass production (ACS) which integrate strips of fast growing trees into agricultural fields, creating a win–win situation for both farmers and society. In this context, developing an easy to use method, accessible to stakeholders with varying backgrounds, is necessary in order to facilitate comparison of ES provision with respect to different land use practices. This study aimed at assessing five regulating services, i.e., carbon sequestration, soil fertility, erosion control, water regulation, and water quality; and one supporting service, i.e., habitat provision, with a tool which had been developed following an empirical approach. The tool is requiring easily accessible data as an input, while linking the selected ES with a set of indicators as an output. Nine indicators were selected and elaborated in the present study. Across German conditions, the functionality of the tool was verified within different scenarios for conventional agriculture (CA) and ACS with various tree proportions. The plausibility of the results obtained was confirmed by related literature. The results suggest improvement in the ES provision of habitat, erosion control, soil fertility, water quality, and carbon sequestration by ACS as compared to CA.