This is a special article collection from the conference „Mapping and assessment of ecosystem services - Science in action“ held in Sofia in February 2017. Ecosystem services have become an amazingly popular topic in science and the number of publications dealing with this subject is increasing. This special issue aims at publishing a variety of ecosystem services research outputs - methods, data, case studies, tools and their applications in science and policy making. The standard discounts are applicable (as per: https://oneecosystem.pensoft.net/about#SpecialIssues).