History and current situation of ecosystem health research

There are three key developmental stages in studying ecosystem health.Planning is the first stage,and includes two sub-stages: the accumulation of knowledge about environmental and ecosystem health,and ideas and thoughts about ecosystem health.The discipline of ecosystem health is established at the second stage and also has two sub-stages: the establishment of basic theories and the development of research methods,which symbols were the first publication of terminology 'ecosystem health' and evaluation method 'VOR',respectively.At the third stage,ecosystem health evaluation starts to be operated in practice,as represented by the development of CVOR theory and related methods.The method of evaluating ecosystem health has been developed through four processes: laying out some simple indicators→integration of these indicators→evaluation of ecosystem function→evaluation of interface processes in ecosystems.This shows that embodying key ecological processes is an important index of selecting indicators to evaluate ecosystem health and multi-indicator integrations are a trend in evaluation of ecosystem health.Ecosystem health is the outcome of multidisciplines and embodies ideas of threshold values.Ecosystem health operates at different levels.