小陇山国家级自然保护区油松林优势种群空间分布格局分析

The spatial pattern of dominant species of Pinus tabuliformisforest in Xiaolong Mountain National Nature Reserve

采用典型样方的方法并应用多个聚集强度指标(方差/均值比率法(C)、负二项参数(k)、Cassie指标(CA)、丛生指标(I)),对甘肃省小陇山油松林优势种群空间分布格局及其动态进行了分析。结果表明:1)所调查区林分中油松种群在总体分布上呈倒"J"字型,表现为群落稳定与正常生长状态;2)区域中油松林木的年龄结构以幼苗为主,空间上主要表现为聚集分布;3)随着群落中油松种群的发育,其聚集强度呈现逐渐下降的趋势,由聚集分布逐渐趋于均匀分布甚至随机分布,指示了群落由发展型向稳定型的过渡。最后分析了聚集分布格局特征与其油松生物学特性和生境的密切关系,油松林优势种群的年龄结构和分布格局综合显示调查区域中该群落正处于旺盛生长期。

In this research the methods of typical quadrat and multiple aggregation intensity index （variance / mean ratio method（C） , negative binomial parameter （k） , Cassie indicators （CA） , clustered index （I） ） were used to analyze the distribution patterns and their dynamics of Pinus tabuliformis community dominant species in Xiaolong Mountain in Gansu Province. The results showed that ： （ 1 ） In the survey area the distribution of Pinus tabuliformis population in general was down ＂J＂ shaped, showing the community stability and the normal growth state;（2） The age structure of Pinus tabuliformis forest was mainly the seedling, and aggregated distribution in space ; （3） With the development of Pinus tabuliformis communities, the gathering intensity showed a gradual de cline, aggregated distribution was gradually moving to the uniform even random distribution, indicating the com munity development model from the transition to the stable. Finally, through analysing the close relationship be tween the aggregated distribution pattern and its biological characteristics, the status quo of the Pinus tabuliformis dominant population age structure and distribution pattern showed that the community was integrated in a strong growth period.