黄帝陵古柏群林下天然更新研究

Natural Regeneration of the Ancient Platycladus orientalis in the Mausoleum of the Yellow Emperor

为实现黄帝陵古柏群的可持续保护,从森林可持续经营理念出发,对黄帝陵古柏群林下天然更新密度和相关环境因子进行了实地调查,采用灰色关联分析法,分析了更新密度与9个相关环境影响因子的关联性。结果表明,林下天然更新影响因子关联度排序为:人为干扰强度>郁闭度>枯落物厚度>坡位>坡度>坡向>枯落物盖度>灌草盖度>海拔,即人为干扰、郁闭度和枯落物盖度对林下天然更新密度影响最大。同时阐明了黄陵古柏群林下天然更新呈现的更新密度小、更新岛屿化以及只见当年生幼苗不见幼树现象的主要原因。提出分区管理,保留更新区;选择性清理林下,保存更新幼苗;适度修剪枯病枝,改善林内环境等促进古柏群林下更新的经营管理措施。

In order to protect the ancient Platycladus orientalis community sustainably, this study focused on an open space survey of the natural regeneration density and related environment factors of the ancient P. orientalis, which was based on the sustainable management theory of forest. The correlation between the natural regeneration density and the 9 related affecting factors were analyzed in terms of environment by using the grey correlation analysis method. The results indicated that the correlation degrees of the 9 factors which were associated with the natural regeneration of ancient P. orientalis ranked as follows： disturbance intensity〉crown density〉litter layer depth〉position〉gradient〉slope aspect〉litter coverage〉shrub and grass coverage〉altitude, indicating that the disturbance intensity, the crown density and the litter layer depth had the biggest influence on the natural regeneration. The results also explained why the natural regeneration was found scattered in this forest with low density, and there were only one-year-old seedlings, but no young trees. According to the results, three management suggestions were given： regionalizing the management to keep the area for natural regeneration; selectively clearing the undergrowth to save the seedlings; moderately pruning the dead and diseased branches to improve the inside environment, to improve the natural regeneration of the P. orientalis.