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为探索华北落叶松水源涵养林的立地适应性和密度合理性,在山西省五台山水源涵养林区,利用标准木树干解析法,对10年生华北落叶松2种密度(2600和3500株.hm-2)的人工林生长过程和直径分布进行研究。结果表明:1)2种林分树高生长量基本相同,几乎不受密度变化的影响;林木直径和立木材积生长过程差别较大;低密度林分的生长状况和密度结构优于高密度林分。2)2种林分直径分布的偏度系数(Sk)差别较大;低密度林分Sk=0.01,接近正态分布,密度结构基本合理;高密度林分Sk=0.45,偏离正态分布,林木密度偏大。2种林分直径分布的峰度系数(K)相差不大(分别为-0.64和-0.74),密度因素对林木分化的作用较小。3)低密度林分的林木胸径、单株材积和干材蓄积生长量逐年增加,没有受到密度的影响;高密度林分的林木胸径、单株材积和干材蓄积生长量从6年生开始明显下降。4)华北落叶松人工林的林龄为10年生时,合理密度约2600株.hm-2;若不考虑10年生之前的间伐利用,可以作为人工造林合理的初植密度。
In order to explore the site adaptability and density rationality of Larix principis-rupprechtii stand in water conservation forest area of Wutai Mountain in Shanxi Province, two kinds of densities of 2-year-old Larix principis-rupprechtii (2600 and 3500 plants.hm- 2) plantation growth process and diameter distribution of the study. The results showed that: 1) The tree height growth of the two stands was basically the same, almost not affected by the density change; the diameter of the forest tree differed greatly from that of the stand volume growth; the growth and density structure of the low density forest was better than that of the high density forest Minute. 2) The difference of the skewness coefficient (Sk) of two kinds of stand diameter distributions is quite different. The low-density stands Sk = 0.01, close to the normal distribution and the density structure is basically reasonable. The high-density stand Sk = 0.45 deviates from the normal distribution, Forest density is too large. The kurtosis coefficient (K) of the diameter distribution of the two forest types did not differ significantly (-0.64 and -0.74, respectively), while the density factor had less effect on the forest differentiation. 3) The DBH, DBM and dry matter accumulation of low-density stands increased year by year without being affected by the density. The DBH, SWC and dry biomass accumulation of high-density stands were significantly increased from 6-year-old decline. 4) When the stand age of Larix principis-rupprechtii plantations is 10 years old, the reasonable density is about 2600 plants.hm-2. If the use of thinning before 10-year-old is not considered, it can be used as reasonable initial planting density of artificial afforestation.