沙地樟子松天然纯林的结构特征

目的]为了解红花尔基地区沙地樟子松天然纯林的结构特征,指导沙地樟子松的保护与经营。方法]在红花尔基地区设置2块100 m×100 m的樟子松天然纯林固定样地,利用样地内每木定位调查数据和分析统计软件进行一元分布及二元分布特征分析。结果](1)樟子松天然林纯林直径分布为单峰或多峰山状分布,垂直结构简单,只有乔木层和草本层。(2)樟子松天然纯林的林木分布格局为均匀分布,接近随机分布,林木分布格局类型与林分密度无关;林分中樟子松个体竞争激烈,多数单元中林木呈较密集状态。(3)2块样地中随机分布状态下的林木多数为中等密集或比较密集,不同分布状态下的林木优劣性差异较小;低密度樟子松天然纯林中多数密集状态的林木为绝对优势木或优势木,而高密度林分中林木密集度分布与林木大小无关。结论]红花尔基沙地樟子松天然林结构不合理,应选择病腐木及聚集分布的个体作为潜在调整对象,进行密度调整和结构优化。

Structure Characters of Pinus sylvestris var.mongolica Natural Forest on Sandy Land

Objective] To understand the structure characters of Pinussylvestris var. mongolica natural forest on Honghuaerji sandy land and provide the basis for protection and management. Method] The data of 2 sample plots of 100 m×100 m with each tree positioning were analyzed by the characteristics of univariate distribution and bivariate distribution with statistical software. Result] The results show that (1)The diameter at breast height (DBH) distribution of P.sylvestris var. mongolica natural forest follows a single or multi shaped peak curve, and the vertical structure is simple, with only tree layer and herb layer. (2) The spatial distribution pattern of P.sylvestris var. mongolica natural forest is uniform distribution, close to random distribution; the spatial distribution pattern has nothing to do with the stand density; the stand in the fierce competition in the majority of individuals of P.sylvestris var. mongolica. (3) Under the condition of random distribution, most trees on the two sample plots are medium dense or dense, with little difference in dominance under different distribution patterns. In low-density P.sylvestris var. mongolicapure forest, most trees in intensive state aredominant trees, while in high-density forest, no relation was found between stand density and tree size distribution. Conclusion] The structure of P.sylvestris var. mongolica natural forest on Honghuaerji sandy land is unreasonable; some measures of density adjustment and structure optimization should be taken to improve the forest health.