不同抚育采伐方式对兴安落叶松林倒木分布格局影响研究

为了解不同抚育采伐方式对倒木分布格局的影响,采用点格局分析法分析不同抚育采伐方式下兴安落叶松原始林、渐伐林和皆伐林内主要树种及不同径级倒木分布格局。结果表明:(1)兴安落叶松原始林、渐伐林、皆伐林中倒木分布格局显著差异,其中原始林随研究尺度增大既有聚集分布也有随机分布,渐伐林均呈显著聚集分布,皆伐林在1~14 m尺度上呈显著聚集分布,其余尺度为随机分布。(2)同原始林相比,渐伐林和皆伐林内兴安落叶松树种倒木均在小尺度呈显著聚集分布,大尺度呈随机分布,而白桦树种倒木均以随机分布为主,只伴有小范围聚集分布。(3)不同抚育采伐方式对小径级倒木分布格局影响显著,对中径级和大径级倒木影响较少。

Impact of Different Cradle Cut Ways on Fallen Wood Distribution Pattern of Larix gmelinii Forest

To understand the impact of different cradle cut ways on the fallen wood distribution pattern, we used the method of point pattern to analyze the distribution patterns of main tree species and different diameter classes of Larix gmelinii virgin forest, deforestation and gradually clear cutting forest under different cradle cut ways. The results showed that: (1) fallen wood distribution pattern of the virgin forest, deforestation and gradually clear cutting forest had significant difference, the virgin forest had both aggregate distribution and random distribution with the increase of the study scale, all deforestation had significantly aggregated distribution, and the gradually clear cutting forest had significantly aggregated distribution on 1-14 meter scale while the rest of the scale was randomly distributed; (2) compared with the virgin forest, Larix gmelinii fallen wood of the deforestation and gradually clear cutting forest had significantly aggregated distribution in small scale and random distribution in large scale, and the fallen wood of Betula platyphylla had mainly random distribution, with only a small range of aggregated distribution; (3) different ways of cradle cut significantly influenced the distribution pattern of trail level fallen wood, and less influenced the pitch diameter and big diameter fallen wood.