Diagnostic Criteria of Ancient Trees Health and Its Application in Middle Reaches of Yellow River

In this study, through information inquiry, field research, data analysis and expert consultation, we screened out morphological indices which are suitable for the health diagnosis of ancient trees in the area and established the grading basis of each index. Then an ancient trees healthy diagnostic criteria was built. According to the criteria, 86 ancient trees (Sophora japonica and Platycladus orientalis) were checked up in Shaanxi midland. It is found the health of ancient trees mostly in the middle and slight discrepancy in different species and the health atatus is positively correlated with the growth of the ancient trees. The results can reflect the true state of ancient trees health with good application effect. Moreover, the factors affecting ancient trees health were analyzed and the corresponding solutions were proposed.