The worldwide research trends on water ecosystem services

In recent decades, the scarcity of water resources, the deterioration of aquatic ecosystems and associated repercussions for other ecosystems have become major global challenges. In this context, research on water ecosystem services has become increasingly important. The objective of this work is to analyse the evolution of this line of research worldwide for the period 1998-2017. A bibliometric analysis showed that this line of research has been gaining relevance within the ecosystem services field. Exponential growth has been observed in such research, and more than 65% of the studies have been performed in the last five years. Economic analyses have little relevance and gradually have lost relative importance. Results show that the most used keywords during the studied period are Ecosystem, Biodiversity, Water Quality, Ecology and Climate Change. The highest contributing countries on this topic are USA, China, UK, Germany and Australia. The leading institutions in this research field are the Chinese Academy of Sciences, the Research Center for Eco-Environmental Sciences and the Wageningen University and Research Centre. A high level of international collaboration is observed between the different agents involved in ecosystem services research and extensive cooperation networks. Three differentiated clusters have been detected around which this type of work is grouped: aquatic ecosystems, forest ecosystems and agricultural ecosystems. The interactions between different types of ecosystems must be investigated with respect to water, and holistic frameworks should be developed that integrate the different disciplines to achieve a more complete analysis of the set of services that contribute to the sustainable management of the different types of ecosystems.