三江源东部祁连圆柏天然更新特征研究

Natural Regeneration Characteristics of Juniperus przewalskii the Forest in the East of Three-River Resource Region

天然更新是维持天然林可持续发展的重要途径,祁连圆柏天然林集中分布于青海三江源地区,了解该林分天然更新状况及影响机制,对于维护三江源水生态安全具有重要的战略意义。本研究以三江源东部麦秀林场祁连圆柏天然林为对象,采用系统调查、室内分析、相关与通径分析相结合的方法,探讨了天然更新状况及影响林分天然更新的关键因子。结果表明:1)林分天然更新不良,平均更新密度为220株·hm^(-2),林下缺乏幼苗补充,更新幼树种群处于衰退状态;2)林龄、林分密度、平均树高、草本盖度、海拔对更新幼树密度的影响达到显著水平,其中林分密度起正向和负向促进作用;林龄、平均树高、草本盖度起间接阻碍作用;海拔起间接促进作用。3)林龄、林分密度、平均树高、海拔是影响更新幼树密度的主要因素。

Natural regeneration is an important way to maintain sustainable development of natural forest.The natural forest of Juniperus przewalskii is mainly distributed in the Three-River Resource Region of Qinghai Province.It is of great strategic significance to investigate the natural regeneration and influence mechanism for maintaining the water ecological security of Three-River Resource Region.In this study,we investigated the natural regeneration and key influencing factors of J.przewalskii forest occurring in the Maixiu Forest Farm located in the east of Three-River Resource Region by using the combination of systematic investigation,laboratory analysis,correlation,and path analysis.The results showed that 1)the natural regeneration was poor,and the average density of the renewal saplings was 220 hm^(2).There was lack of seedling supplement understory,and the population of the saplings was in a state of decline.2)The effects of stand age,stand density,average height,herb coverage and altitude were significant,among them,the stand density had a direct and indirect positive influence,the stand age,average height and herb coverage presented indirect negative influence,while the altitude had an indirect positive influence.3)The main factors affecting the density of the saplings were stand age,stand density,average height and elevation.