Research review on methods of grassland health assessment

Grassland health refers to the degree to which the integrity of soil and ecological processes is maintained, which primarily reflects the health status and productivity of grasslands. Evaluating the degree of grassland health is vital for the sustainable develop of grasslands. There are many methods for evaluating grassland health, with advantages and disadvantages for each one. However, there is still a lack of systematic literature offering an overview of methods of grassland health assessment and their applicability. We summarized 10 methods of grassland health assessment, including vigor-organization-resilience (VOR) index evaluation model, condition-vigor-organization-resilience (CVOR) index evaluation model, principal component analysis method, analytic hierarchy process, cluster analysis method, grey relational analysis, pressure-state-response evaluation model, fuzzy comprehensive evaluation method, comprehensive evaluation model of grassland health, and evaluation model using remote sensing technology. The advantages, disadvantages, and applicability of these methods were discussed, aiming to provide scientific basis for selecting more suitable methods of grassland health assessment for different scenarios in the future.