摘要
结合10个断面的30个样地野外调查结果,采用物种丰富度指数(R)、Shannon-Wiener指数(H)、Simpson优势度指数(D)、物种均匀度指数(JSW)、Whittaker指数、Cody指数、扩散系数(C)、负二项参数(K)、平均拥挤度(m*)、丛生指标(I)、聚块性指标(PI)、Green指数(CA)、Cassie指标(GI)综合分析了塔里木河下游绿洲-荒漠过渡带植物群落多样性及优势种群的空间分布格局。结果表明:塔里木河下游绿洲-荒漠过渡带优势种群为胡杨(Pop-ulus euphratica)、柽柳(Tamarixspp.)、黑果枸杞(Lycium ruthenicum)、盐穗木(Halostachys caspica)、花花柴(Karelinia caspica)、芦苇(Phragmites communis)、骆驼刺(Alhagi sparsifolia)、甘草(Glycyrrhiza inflata)、罗布麻(Apocynum hendersonii),受生境中水分条件的影响,各种群均呈聚集分布格局;各群落α-多样性指数低,物种多样性呈梯度变化,受环境水土资源条件限制,物种丰富度变化为:绿洲内>交错区>荒漠区;受地下水埋深的影响,群落结构呈规律性变化:乔-灌-草结构—灌-草结构—单一灌木结构—灌-草结构—乔-灌-草结构;Whittaker指数、Cody指数显示群落β-多样性随着地下水埋深梯度发生变化,过渡带是绿洲和荒漠物种分布变化的分界地带。因此,地下水埋深是决定塔里木河下游绿洲-荒漠过渡带物种多样性和种群分布的决定因素。
Synthesis dominance rate （SDR）, Richness index （R）, Shannon-Wiener index （H）, Simpson index （D）, Pielou index （Jsw）, Whittaker index （βwc）, Cody index （βc）, Dispersion index （C）, Negative binomial parameter （K）, Mean crowding intensity （m^＊）, Clumping index （I）, Patchiness index （PI）, Cassie index （GI） and Green index （CA） are used to analyze the species diversity and dominance population distribution pattern based on field surveying data from 30 plots along 10 sections at oasis-desert ecotone in the lower reaches of the Tarim River. The results showed that the structure and composition of these communities were simple, the dominance populations were Populus euphratica, Tamarix chinensis Lour., Lycium ruthenicum, Halostachys caspic, Karelinia caspica, Phragmites communis, Alhagi sparsifolia, Glycyrrhiza inflate, Poacynum hendersonii, and they distributed in aggregative state in responding to groundwater depth. The a-diversity indices of these communities were low, and species diversity showed gradient change. The richness index followed the order： oasis〉 ecotone〉 desert due to water resource difference in microenvironment. From ecotone to desert, the community structure changed from tree-shrubherbage to shrub-herbage to single shrub to shrub-herbage, and to tree-shrub-herbage due to change of groundwater depth. Suggested by Whittaker index and Cody index, the β-diversity indices of these communities changed with groundwater depth gradient, showing the ecotone was the boundary between oasis species and desert species distribution. Therefore, the groundwater depth was the decision factor for species diversity and distribution pattern of dominance population at oasis-desert ecotone in the lower reaches of the Tarim River.
出处
《中国沙漠》
CSCD
北大核心
2009年第4期688-696,共9页
Journal of Desert Research
基金
国家自然科学基金项目(90502004
30500081)
中国科学院西部行动计划项目(KZCX2-XB2-03)
国家"十一五"科技支撑项目(2006BAC01A03)共同资助
作者简介
周洪华（1980-），女，四川人，博士研究生，从事干旱区生态修复及生态安全研究。Email：zhoushixin1980@163．com
通讯作者：陈亚宁（chenyn@ms．xjb．ac．cn）
