Grassland Ecosystem Services: Their Economic Evaluation through a Systematic Review

Grasslands provide a wide range of provision, support, regulation, and cultural ecosystem services (ESs), whose valuation methods can be grouped into three categories (ecological, sociocultural, and economic). The present manuscript aims to provide an overview of academic studies on grassland ESs and of the most used economic evaluation methods. To this end, a systematic and bibliometric review was conducted using the scientific database Scopus and the VOSviewer software. The results highlighted that China and the USA were the main countries with the highest number of publications regarding ESs provided by grasslands. The number of publications began to grow starting in 2005, thanks, perhaps, to the publication of influential documents, such as the Millennium Ecosystem Assessment, and the general increase in interest in ecological policy issues. The year 2023 had the highest number of documents in absolute (646), demonstrating the timeliness, importance, and relevance of this research topic. The most studied grassland ES has been carbon storage; however, a central role was played also by biodiversity. In this context, papers that estimated grassland ESs from an economic perspective represented only 3% of all papers that Scopus has returned. More than half of these referred to the use of equivalent coefficients to calculate the ES value of different land uses/land cover categories or, at most, of 11 types of ES. All this highlights the difficulty in estimating individual ESs provided by grasslands from an economic point of view and the greater propensity to use physical, chemical, and biological indicators. Consequently, the sustainable management of grasslands requires more studies on the economic evaluation of their ES, as well as environmental aspects in the economic accounting of governments, or to implement a support system for farms in delivering various ecosystem services.