杉木中幼林抚育间伐是提高生长量的重要途径,也是提高经济效益最快的有效措施。但是,始伐年龄必须适当,否则对林木的生长和经济收入都是不利的。始伐年龄过早,对促进林木生长的作用不大,经济收入也少。始伐年龄过迟,虽可提高间伐利用价值,但不利于林分的速生丰产。何时开始进行抚育间伐比较适当呢?要 Thinning of young and middle-aged Chinese fir forest is an important way to increase the amount of growth, but also to improve the economic efficiency of the fastest effective measures. However, the initial cutting age must be appropriate, otherwise forest growth and economic income are adverse. Early pre-harvesting has little effect on forest growth and low economic income. The late initiation of cutting will increase the value of thinning and utilization, but not conducive to fast-growing and high yielding forests. When is it appropriate to start tending?