Abstract: Determination of health sequence’s evaluation indices is the key of health sequenceanalysis. In this paper, fuzzy discrimination method was used to analyze the health status of Haloxylon ammodendron community in Minqin sandy region, and a health evaluation index system for degraded plant communities was established, including plant state index, morbidity index, biodiversity index, and natural regeneration capacity index. The results better reflected the health status of different communities, and the relationships between community health sequence and dominant and associated plant species. In general, the comparative study on the health status evaluation of several targets was much easier than that of only one target. For desert plant communities, first and secondgrade discriminations should be conducted with trees, shrubs, and herbaceous plants separately, and a sensitivity analysis should be carried out on secondgrade discrimination.

Key words: Soil water potential, Transpiration, Water suction by roots, Plant water potential, Hydraulic resistance, Fraxinus mandshurica