不同林分密度对日本落叶松生物量的影响

[目的]快速培育优质高产日本落叶松人工林,优选最佳的适宜密度。[方法]设间伐强度20.00%、30.00%、40.00%、对照4个处理,即Ⅰ号区2 235株/hm~2,Ⅱ号区1 995株/hm~2,Ⅲ号区1 365株/hm~2,Ⅳ号区2 975.00株/hm~2(CK),选择18年生的林分进行不同保留密度的试验研究。[结果]10年间各试验区日本落叶松的生物量变化比较明显,Ⅱ号区保留密度1 365株/hm~2,乔林层生物量比CK提高74.80%,总林分生物量比CK提高72.22%;Ⅲ号区保留密度810株/hm~2,林分乔木层生物量比CK降低3.94%,林分总生物量比CK降低3.36%,而草本层和灌木层的生物量比CK分别提高2.53%和20.34%。[结论]在日本落叶松中龄阶段,林分的保留密度以1 365株/hm~2为宜。

Effects of Different Stand Density on Biomass of Larix kaempferi

[Objective]To cultivate high quality and high yield Larix kaempferi plantation, and to select the best suitable density.[Method]Set up the thinning intensity of 20%, 30%, 40% and the control of the 4 treatments, namely, Ⅰ area 2 235 plant/hm2, Ⅱ area 1 995 plant/hm2, Ⅲ area 1 365 plant/hm2, Ⅳ area 2 975 plant/hm2 (CK), the experimental study on the selection of 18 year old stand in different density was conducted.[Result]In the 10 years, the biomass of Larix kaempferi was significantly changed in each test area.The density was 1 365 plant/hm2 in Ⅱ area, and the biomass of the forest was increased 74.80% by comparing with CK, the total biomass was increased 72.22% by comparing with CK.The density was 810 plant/hm2 in Ⅲ area, and the biomass of the forest was decreased 3.94% by comparing with CK, the total biomass was decreased 3.36% by comparing with CK.The biomass of herb layer and shrub layer increased 2.53% and 20.34%, respectively, by comparing with CK.[Conclusion]In middle age stage of Larix kaempferi, the density of the stand was 1 365 plant/hm2.