新疆奇台荒漠植物群落的数量分类及土壤环境解释

为阐明古尔班通古特沙漠南缘荒漠植物群落的分类及与土壤因子的相关关系, 作者于2005年6–7月在新疆奇台县采用机械布设样线和样线上随机布设样地的方法进行了野外调查。共设置48块20 m×10 m的样方, 每个样方中又梅花状设置5个1 m×1 m的草本样方进行植被调查。植被调查结束后, 选择群落外貌上差异显著的样地进行土壤取样(取土深度分别为0 cm、10 cm、30 cm、50 cm、80 cm), 共获得20个样方的土壤样本。以植物重要值作为衡量植物组成相似性的指标, 应用逐步聚类的方法将调查区域植被划分为4种类型: 芦苇(Phragmites australis)+芨芨草(Achnatherum splendens)群落, 梭梭(Haloxylon ammodendron)–枇杷柴(Reaumuria songarica)+西伯利亚白刺群落(Nitraria sibirica), 梭梭–心叶驼绒藜(Ceratoides ewersmanniana)–白茎绢蒿(Seriphidium terrae-albae)群落和心叶驼绒藜–骆驼刺(Alhagi sparsifolia)群落。不同群落类型土壤因子的主成分分析的结果表明: 提取3个主分量能够解释85.65％的群落间土壤因子差异, 第1主分量与土壤平均pH值和深层土壤pH值相关, 第2主分量与平均有机质含量和土壤浅层有机质含量相关, 而第3主分量与平均土壤含盐量和土壤浅层含盐量相关。

The numerical classification of desert vegetation and soil interpretation in Qitai County, Xinjiang

In order to explore the correlations between desert plant community types and soil variables at the southern edge of Gurbantunggut Desert, we established 48 quadrats of 20 m × 10 m to study the vegetation by the randomized systematic method in Qitai County of Xinjiang in 2005. After vegetation survey, we selected 20 plots with obviously different physiognomy and sampled soils at 0, 10, 30, 50 and 80 cm depths, respectively. Plants and soil characters were analyzed simultaneously and the results were correlated. A hier-archical cluster and principle component analysis (PCA) were performed based on importance value of plant species and soil variables, respectively. Four types of communities were recognized and described in details, i.e. Phragmites australis + Achnatherum splendens community, Haloxylon ammodendron+Reaumuria son-garica+Nitraria sibirica community, Haloxylon ammodendron+Ceratoides ewersmanniana+ Seriphidium terrae-albae community, and Ceratoides ewersmannian+Alhagi sparsifolia community. The results of prin-ciple component analysis showed that there was a specific relationship between soil variables and plant community type. Three principal components, namely pH, organic matter content, and soil salinity, could ex-plain 85.65% of the differences among the soils of different plant communities.