侧柏水土保持林密度调控

Regulation Density of Soil and Water Conservation Forest of Platycladus orientalis

根据侧柏人工林胸径和冠幅的相关关系 ,编制了适宜经营密度表。通过 10年观测 ,侵蚀模数与植被覆盖率的定量关系 ,石灰岩低山区土壤允许流失量 6 0t/km2 .a作为无明显侵蚀的界限。当水土保持林覆盖率为 4 9.3%时 ,土壤流失量等于允许流失量 ,此时径阶 4、6、8、10、12、14、16、18、2 0cm的侧柏每 6 6 6 .7m2 保留株数分别为 2 95、186、12 1、87、6 2、5 1、4 1、34、2 8株。

The management density table was charted according to the relationships between the diameter breast highand crown of the natural secondary forest of Platycladus orientalis.The amount of permitted soil losses was 60t/(km 2.a) regarded as a limit of not being eroded obviously through 10-year observation of the quantitative relationships between erosion mod function and plant percentage.The amount of soil losses in gentle limestone hill equaled that of permitted losses while the soil and water conservation forest percentage in 49.3%.At the same time,the optimum stant density is 295,186,121,87,62,51,41,34,28 trees per 666.7m 2 while the stem diameter grade is 4,6,8,10,12,14,16,18,20cm respertively.