Measuring ecological capital: State of the art, trends, and challenges

It is essential to assess the value of nature, as it provides various benefits for human economic development and well-being. It has been 20 years since two prominent publications came out in valuing nature. New concepts and methods have emerged since then. This study aimed to (1) investigate the relationship between the new proposed concept (ecological capital) and the existing two concepts: natural capital and ecosystem services and (2) examine the research trends of ecological capital accounting publications from 1997 to 2017. Bibliometric analysis was used to reveal the research trends. The results showed that the total number of publications has rapidly increased since 1997 and this growth trend will be maintained in the future. The most productive journal, country, institute, and author were Ecological Economics, USA, Chinese Academy of Sciences, and Dr. Verburg, respectively. Ecosystem services and land were the most frequent types of ecological capital. Non-economic evaluation approaches became less of a favorite over time and economic valuation methods were mostly applied in last five years. The integration of different methods has attracted increasing academic attention. The progress, advantages, and limitations of different methods were summarized in this study, including SEEA, ecological footprint, exergy, emergy, LCA, and economic valuation approaches, as well as newly developed modelling approaches. The last part of this study presented three challenges in this academic field - the need to (1) establish a standard framework, (2) consider the transfer/transport of ecological capital, and (3) improve capabilities for decision-making. (C) 2019 Elsevier Ltd. All rights reserved.