[Regional suitability analysis of endangered medicinal plant Dactylorhiza hatagirea]

The wild plant Dactylorhiza hatagirea commonly used in Tibetan medicine. In recent years, it is on the verge of extinction due to improper excavation and habitat deterioration. Based on the literature review, and the meteorological and ecological data of Qinghai Province and data derived from the field survey, this study took the altitude, humidity index, annual average wind speed, monthly average sunshine, precipitation and temperature in growing season, soil type and vegetation type as the zoning indexes, and applied ArcGIS software for spatial superposition analysis. The results showed that the D. hatagirea was primarily found in the alpine meadow in the east and south of Qinghai Province. The overall suitable area was about 30 700 km~2. Taking Qinghai Lake as the boundary for reference, the area in the south appeared to be more suitable, while the area in the east appeared to be secondary in suitability. Henan County, Zeku County, Jiuzhi County and Banma County were the main suitable areas covering the expanse of 12 454 km~2. Through the field verification, such zoning results appeared to be accurate, precise and illustrative. The spatial distribution of ecological suitability provides the decision-making basis for the resource investigation, environment protection and comprehensive resource management. It also provides the empirical case for developing the interdisciplinary research method in the suitability study of medicinal plants.