Ecosystem intrinsic value and its evaluation

•The ecosystem intrinsic value (EIV) is an objective value of the ecosystem in and for itself.•EIV can be measured by calculating the work capacity of an ecosystem.•The value of information in ecosystems is incorporated in EIV.•EIV evaluation is developed based on exergy, eco-exergy and development capacity analysis.•Results of EIV density from three case studies reflect the intrinsic properties of ecosystems. The objective recognition and scientific evaluation of ecosystem values are essential for sustainable decision-making and nature conservation. However, the ecosystem services value, which is the most popular concept, measures ecosystem value mainly through an estimation of the “willingness-to-pay” of individuals and thus can cause a bias in estimating ecosystem value. The ecosystem intrinsic value (EIV), which has been recognized by the Millennium Ecosystem Assessment and The Economics of Ecosystems and Biodiversity, is an objective value of ecosystems. In this study, the EIV is defined as the objective value of the ecosystem in and for itself irrespective of needs, wants, and benefits of humans. Specifically, EIV is an integration of matter, energy, and information of an ecosystem, which can be measured by calculating the work capacity. Furthermore, an EIV approach based on exergy, eco-exergy, and development capacity analysis was developed for EIV evaluation and then applied in three marine ecosystems, i.e., Northern Beibu Gulf, Bohai Sea, and Yangtze Estuarine and its adjacent waters in China. A comparison among three case studies in different years showed that the EIV density is ranked in the following sequence: Yangtze Estuarine and adjacent waters (2000) > Northern Beibu Gulf (2006) > Yangtze Estuarine and adjacent waters (2006) > Bohai Sea (1982) > Bohai Sea (1992). The results of EIV density reflect the intrinsic properties of the ecosystems and is determined only by the ecosystem itself. The results have demonstrated to some extent that temperature and nutrients are playing important roles in controlling ecosystem productivity, further affecting the work capacity and determining EIV of the ecosystem. The approach and methods established in this study provide a stricter and more objective pathway for evaluating ecosystem value compared to our previous study, which is expected to improve current decision-making processes towards sustainability.