Review of ecosystem asset quality assessment methods and progress

Ecosystem assets, as an important part of the natural resource assets to support human socio-economic development, are the basis for the provision of ecosystem products and services to humans, and consequently for the generation of ecological benefits and gross ecosystem product, including natural ecosystems such as forests and grasslands, artificial ecosystems based on natural ecological processes such as farmland and urban green space, as well as wildlife resources. Ecosystem asset quality is the synthesis of structural and functional characteristics of ecosystems, reflecting the capacity to provide ecosystem services sustainably. Assessing the ecosystem asset quality is one of the most complex parts in ecosystem asset accounting. As a new perspective of ecosystem accounting, ecosystem asset quality emphasizes both natural and socio-economic attributes of ecosystems, which is highly significant in promoting ecosystem valorization, ecosystem asset management and the realization of the value of ecosystem products. In this review, we systematically summarize the concepts, assessment methods and indicators of ecosystem asset quality, and also provide an overview of global relevant cases. Issues, such as the improvement of the indicator system and the comprehensive assessment, and suggestions for the assessment of ecosystem asset quality are proposed to establish a framework for future research, and to promote global ecosystem assessment and accounting with its application in ecological and environmental protection policymaking.