Introduction to the original secondary forest: The original forest in the limestone area in Jiumu River is the low-mountain evergreen broad-leaved forest with the lowest altitude and the most plant species in the limestone area of Hunan Province; it has the lowest evergreen broad-leaved forest in the country, with the lowest altitude 250 meters; there is the Osmanthus fragrans community with the lowest altitude and the largest area in China, with an altitude of 350-450 meters, covering an area of about 200 acres; there is the Bole tree community with the lowest altitude in China, with an altitude of 400-550 meters; on the ridge There are hundreds of hectares of well-preserved pure forest communities of Quercus sibirica, Quercus ugangensis and Quercus Badong on the steep rock faces.