摘要
在太白山自然保护区设置 2 0 m× 2 0 m样地 8块 ,应用相邻格子法进行每木调查 ,并对巴山冷杉(Abies fargesii)种群结构和分布格局进行了动态分析。结果表明 ,种群大小结构为进展型 ,幼苗、幼树的后备资源储备量大 ,约 95 4株 / hm2 ;种群在 ~ 发育阶段死亡率较高 ,达 82 .3% ,随后死亡率趋于稳定 ;存活曲线属于Pearl 或 Deevey C型 ;种群的空间分布格局总体为聚集分布 ,负二项分布参数 (K) 1.6 0 0 ,扩散型指数 (Iδ) 1.6 2 9,丛生指标 (I) 7.6 77,Cassie指标 (CA) 0 .6 2 5 ,扩散系数 (C) 8.6 77,聚块性指标 (m* / m) 1.6 2 5。离散拟合符合负二项分布模型 ;但随着植株年龄的增长及发育阶段的不同 ,分布格局由初期的聚集分布逐渐扩散为随机分布 ,离散拟合由负二项 (Negative Binomial)分布转变为泊松 (Poisson)
m 2 plots were established in Taibai Mountain Nature Reserve for the obtaining of sampling data by tally in the contiguous quadrats.Through the dynamic analysis of Abies fargesii population structure and distribution pattern,the results showed that:the diameter structure was developing and the resources of little and young trees were great,about 954 plants/hm 2;the death rate of Ⅰ-Ⅳpopulation was as higher as 82.3%,and then it became steady.The survivor curve belonged to Pearl Ⅲ or Deevey C type;the distribution pattern was clustering in general.Parameter of negative binominal ( K ) was 1.600.Dispersal index( I δ )was 1.629.Index of clumping( I )was 7.677.Cassie index ( C A )was 0.625.Distribution index( C )was 8.677 and index of patchiness( m */m )was 1.625.The result of discrete distribution fitting was negative binominal distribution.With the increase of age and difference of development phases,the distribution pattern changed from aggressive distribution to random distribution and the result of discrete distribution fitting changed from negative binominal distribution to Poisson distribution.
出处
《西北农林科技大学学报(自然科学版)》
CSCD
北大核心
2001年第5期115-118,共4页
Journal of Northwest A&F University(Natural Science Edition)
基金
陕西省自然科学基础研究计划项目 ( 98SM0 8)