带状间伐促进赤松人工林天然更新效果的研究--天然更新的综合效果与分布格局

通过在人工林内带状间伐开拓天然更新效应带，分析了赤松在不同试验地内的天然更新效果和更新种群的分布格局．结果表明：(1)采伐带和保留带内更新幼苗幼树的数量分别达到5l100株／hm^2和48300株／hm^2，是对照林19300株／hm^2的2．6倍和2．5倍．(2)更新种群中属于更新层的苗木占主体，采伐带占78％，保留带占89％，对比林占83％．进入演替层的幼树以采伐带最多，达11500株／hm^2，是保留带和对照林的2．1倍和3．6倍．(3)采伐带内更新苗的苗高跨度在0～500cm之间，保留带为0～300cm，对照林为0～450cm，各试验地都以0～10cm苗高范围内的幼苗数量最多．(4)赤松更新种群的空间分布格局为聚集型，三种试验地内更新种群的分布都遵循负二项分布，其中保留带和采伐带内的更新种群还同时遵循奈曼分布．说明带状采伐有利于促进赤松天然更新和幼苗生长，为延边地区赤松林的经营提供了依据．

The effect on natural regeneration of Pinus densiflora plantation by cutting in strip--The comprehensive effects and distribution pattern of natural regeneration

Based on cutting in strip to increase natural regeneration in Pinus densiflora plantation, the natural regeneration effects and distribution patterns of regeneration population were analyzed. The results showed that the numbers of seedlings and young trees were 51 100 stems/hm2 in cutting strip and 48 300 stems/hm2 in reserving strip, which were 2. 6 and 2. 5 times as much as uncut stand (CK), respectively. The seedlings in regeneration layer occupied main part in regeneration population, and they occupied 78% in cutting strip, 89% in reserving strip and 83% in uncut stand. The young trees in succession layer were most in cutting strip, 11 500 stems/hm2, which were 2. 1 times as much as that in reserving strip and 3. 6 times as much as that in uncut stand. The ranges of seedling height were 0-500 cm in cutting strip, 0-300 cm in reserving strip and 0 - 450 cm in uncut stand. Most seedlings were 0-10 cm in three test spots. The distributions of regeneration population were aggregated in three test spots, they all obeyed negative binomial distribution, in the meanwhile those in reserving strip and cutting strip were also obeyed Neyman distribution. The calculation and analyses showed that cutting in strip could enhance natural regeneration and increase seedling growth. They afforded the necessary bases for the management of Pinus densiflora in Yanbian area.