山西黄土丘陵区天然油松林幼苗更新等级评定及结构分析

Assessment and Structure Change of Natural Pinus tabulaeformis Seedlings in Shanxi Loess Hilly Region

选取山西省黑茶山国有林管理局城庄沟林场内典型天然油松林,采用标准地调查法调查其更新情况,结果显示:该区域内天然油松林下更新树种主要有油松(Pinus tabulaeformis)、白桦(Betula platyphylla)、辽东栎(Quercus wutaishansea)、皂柳(Salix wallichiana)、落叶松(Larix gmelinii),天然更新等级为中等。油松幼苗的年龄结构有着非常明显的变化,各年龄阶段的油松幼苗个体数分布不均匀;油松天然更新幼苗都在4年生以上,占总数量的90.6%,4年生以下的幼龄苗数量非常少。油松天然更新幼苗高度级个体数结构图呈"L"形,个体频率高峰出现在高度级较高的级别上,高度级较低的油松幼苗数量较少,可采取适当的人为干扰措施,减轻幼苗间的生存竞争,以促进该区域内油松天然更新幼苗成林。

Taking natural Pinus tabulaeformis plantation in Chengzhuanggou Forest Farm of Heichashan Stateowned Administration Bureau in Shanxi Province as research object,the regeneration of tree species was investigated by adopting survey method of standard plot.Result shows that the main regeneration species in this region are Pinus tabulaeformis,Betula platyphylla,Quercus wutaishansea,Salix wallichiana & Larix gmelinii,the natural regeneration grade of Pinus tabulaeformis forest is medium.The age structure of seedlings of Pinus tabulaeformis is significantly different.The seedling number of different ages is different.The Pinus tabulaeformis seedlings are more than 4 years old,which accounted for 90.6%,the seedlings below 4 years old is few.The structure diagram of height class which is the individual number of regeneration seedlings of Pinus tabulaeformis is"L"type,the individual frequency peak appear at the higher height level,the lower height is less.Appropriate human-interference measures should be taken to reduce the survival competition among the seedlings,in order to promote the natural regeneration in natural Pinus tabulaeformis plantation.