Natural Environment of Shimen National Forest Park

The geological structure of Shimen National Forest Park is located in the structural unit of Yue Zhong Depression in South China Fold System, which is the junction of Nankun Mountain and Qingyun Mountain in the south of Jiulian Mountain. There are three main types of landforms: Zhongshan, low mountains and hills. The mountain is mainly uplifted by Himalayan movement and neotectonic movement since Tertiary, among which there are dozens of peaks above 800m, the highest peak is Tiantangding, and the altitude is12100 m. Because the mountain development process is controlled by geological structure, the main structural features are northeast, east-west and northwest, and the arrangement of leading valleys is basically consistent with the direction of structural lines, forming a steep valley landscape.

The mother rocks of Forest Park are mainly granite, followed by sandstone, shale and metamorphic rocks, with a small amount of volcanic rocks. From the hills and ridges around SOOm at an altitude of 270 meters in the west, it gradually rises to the low mountains at an altitude of 800 meters and the ridges at an altitude of 800- 1 100 meters in the northeast, north and southeast. The central valley is narrow, and the relative elevation of the mountains on both sides is 200-400m, and the slope is above 25 degrees. So the terrain is high in the southeast and low in the northwest, surrounded by mountains on three sides. Forest Park is located in the northern edge of the Tropic of Cancer and belongs to the south subtropical monsoon climate type. Affected by the monsoon, it is characterized by cold summer and warm winter, abundant light energy and abundant rainfall.

The annual average temperature of forest park is 2 1.40℃, in which the maximum temperature is Leng Yue 1 month, the average temperature is 12.4℃, and the extreme minimum temperature is-7℃; The hottest month is July, with an average temperature of 28.5 degrees Celsius and an extreme maximum temperature of 38. 10 degrees Celsius. The annual average light hours are 1774.2 hours, and the monthly average oral light hours are around 170 hours, with the highest in July-10 month. There is abundant precipitation, with an annual average of1800 mm. The main precipitation season is from May to August, and the conditions are good, which is conducive to plant growth. The main disastrous weather is low temperature, mainly concentrated in May-August.