From payments for ecosystem services to eco-compensation: Conceptual change or paradigm shift?

Payments for ecosystem services (PES) is an effective policy in conserving ecosystem services and is increasingly applied globally. The concept of PES was firstly defined in 2005, researches with various terminologies, concepts, and practices emerged since then. This paper analyzed the research patterns of PES studies through bibliometric methods, with a special focus on the trends of terminology, location (geographical research hotspot), types of PES, and PES effectiveness evaluation based on author keywords analysis. The results showed that PES started to receive considerable academic attentions from 2005, and the number of PES publications have relatively kept an increasing trend since then. The most influential journal, country, research organization, and author were Ecological Economics, USA, Chinese Academy of Sciences (CAS, China), and Dr. Wunder. Further analysis revealed that there were various terminologies in PES studies, notably "ecological compensation" and "eco-compensation" (EC) were primarily adapted by Chinese research community. China was the geographical research hotspot and developing countries (Vietnam, Mexico, and Brazil) have received growing academic interests in last decade. "Forest and Carbon" PES was the most concerned types of PES in last five years. There were 125 articles evaluated the effectiveness of empirical PES initiatives, and the majority focused on the social aspect. We proposed two suggestions for future research: (1) adapting EC as an alternative term for PES studies because of its inclusiveness and representation of empirical practices; (2) enhancing integrated evaluation of PES programs to achieve multiple benefits.