落叶松人工林动态间伐系统的研究Ⅱ

于1970年至1984年对我校帽儿山实验林场1958年春栽植的落叶松(Larix gmelini)人工林进行了系统的试验研究。 首先对落叶松人工林进行了以小群体为单元的林木分级,共分五级,即A、B、C、D、E级。每个小群体是以每株林木为中心位置与其相邻的林木所组成的,共七株林木,中心林木一株,周围六株,组成六边形的空间状态。 本试验共分五个组合,第一区抚育强度基本控制在10％、第二区为20％、第三区为30％、第四区为40％、第五区为对照区。 间伐对象:原则是培育A级木、间伐B级木、解放C级木,清除D、E级木,在实施过程中还要因立地条件和林木位置做某些调正。 经过14年的试验结果表明,以对照区第一次间伐后林分蓄积量为100％,第一区为114.9％,第二区为128.4％,第三区为133.1％,第四区为118.5％,属第三区生长量最大。此外,林木径级生长量、生物量、总的重量均有显著增加,由此看出,根据林木竞争状态转移的规律和森林生态经济的理论,而提出的间伐方法是科学的有效的。

THE METHOD AND INTENSITY OF INTERMEDIATE CUTTINGS FOR LARCH PLANTATION

The systematic trial was conducted in a larch plantation (Larix graelinii) which was planted in the spring of 1958 at Maoershan Forest Farm. First of all, the classification of tree grade composed of five classes (A, B, C, D, E) was made and the whole plantation was divided into numerous small group at the beginning of the trial. Each small group was composed of one central tree and six adjacent trees associated in a form of hexagon. For the convenience of comparision, the stand used for the trial was divided into five experimental plots in which the cutting intensity for each plot was controlled as follows: 10% for the first plot; 20% for the second plot; 30% for the third plot; 40% for the fourth plot; the fifth plot without cuttings for comparison.The intermediate cutting operation was carried out according to the principle of reserving A-class trees, cutting B-class trees in theintensity as required, releasing C-class trees, and removing D-E-class trees.Through 14 years study, the research results show that if the stand volume of control plot is considered as 100% after the first cutting, the volume of other plots are calculated as follows: 114.9% for the first plot; 128.4% for the second plot; 133.1% for the third plot; 118.5% for the fourth plot. The further details about the increment of diameter and height growth, and biomass are alto expounded in this paper.