Ecosystem service: from virtual reality to ground truth.

E service is the collective name for the benefits that people obtain from ecosystems. As a scientific concept, it can be dated back to the 1960s; whereas, the proliferation of ecosystem service research has been since the late 1990s driving by the increasing environmental concerns of human societies. Ecosystem service has been defined from an anthropocentric perspective that links ecosystems and human society by unilateral benefit flows. Therefore, the heating up of ecosystem service research in the past decade started from the recognition and monetary valuation of the benefit flows from ecosystems to society. The purpose of this movement is to raise serious concerns on the overwhelming importance of healthy ecosystems for human wellbeing and inform wise policies and actions for ecosystem use, conservation, and sustainable management. The millennium Ecosystem Assessment classified ecosystem services into four broad categories including supporting services, provisioning services, regulating services, and cultural services. This has been widely appreciated but not the items within each category. Former classifications of ecosystem services were challenged on their tendencies to exchange use of ecosystem processes and services as well as insufficient or vague terminologies. Beyond classification, there comes the modeling, quantification, and valuation of ecosystem services. These processes are indispensible for decision-making in ecosystem management and land use planning to provide quantitative information and tools. We carried out literature searches in the ISI Web of Science using three topic combinations including Search syntax 1 “TS=ecosystem service and TS=model”, Search syntax 2 “TS=ecosystem service and TS=valuation”, and Search syntax 3 “TS=ecosystem service and TS=quantification”. These searches retrieved 1237, 525, and 58 records, respectively. Research articles published in peer-reviewed academic journals dominated these records (over 84%). The yearly percentage distributions of the records revealed an accelerated rate of publications on methodological issues in ecosystem service research including modeling, valuation, and quantification (Figure 1).