Abstract:

After 13 years observing the seabuchthorn's crown density and height, the woodland's illumination, soil bulk density, soil porosity, soil nutrient, and the Chinese Pine's survival percent, height, basal diameter and top shoot growth of mixed stands of seabuckthorn and Chinese Pine that mixed by rows, by rows and cutting seabuckthorn, by strips, by wide rows, by wide rows and cutting seabuckthorn, and comparing these treatments with pure stand of Chinese Pine in loess hilly and gully region of northern Shaanxi. The results showed that the seabuchthorn's crown density and height of mixed by rows and mixed by wide rows were higher than mixed by rows and cutting seabuckthorn, mixed by strips, and mixed by wide rows and cutting seabuckthorn. Woodland illumination of pure stand of Chinese Pine was higher, mixed by strips, that of mixed by wide rows and cutting seabuckthorn, and mixed by rows and cutting seabuckthorn was in the middle, that of mixed by rows and mixed by wide rows was lower. After 11 years, soil water content of mixed by rows and mixed by wide rows was higher, that of mixed by rows and cutting seabuckthorn, mixed by strips, and mixed by wide rows and cutting seabuckthorn was in the middle, pure stand of Chinese Pine was lower. The higher the seabuchthorn's crown density and height were, the lower the soil bulk densities of different treatments were, and the higher the soil porosity and soil nutrient were. The height and the basal diameter of Chinese Pine that mixed by rows and mixed by wide rows were lower obviously after 6 years, the survival percent was increased obviously after 7 years. The heights of Chinese Pine that mixed by rows and cutting seabuckthorn, mixed by wide rows and cutting seabuckthorn and mixed by strips were higher after 7 years, and the height of Chinese Pine that mixed by rows and cutting seabuckthorn, mixed by wide rows and cutting seabuckthorn were higher than that mixed by strips after 10 years. The basal diameter of Chinese Pine that mixed by rows and cutting seabuckthorn, mixed by wide rows and cutting seabuckthorn and mixed by strips were bigger than that of pure stand of Chinese Pine after 9 years. The annual increment of top shoot of Chinese Pine that mixed by rows and cutting seabuckthorn, mixed by wide rows and cutting seabuckthorn and mixed by strip were higher, mixed by rows and mixed by wide rows were lower. The growth of Chinese Pine, mixed by rows and cutting seabuckthorn, mixed by wide rows and cutting seabuckthorn and mixed by strips had been promoted. The survival percent of Chinese Pine mixed by rows and mixed by wide rows had been reduced, and had restrained the growth of Chinese Pine.

Key words: Chinese Pine, seabuckthorn, mixed pattern, habitat, growth