岷江上游茂县半干旱河谷灌丛优势种间关系的研究

STUDIES ON THE INTERSPECIFIC RELATIONSHIP AMONG DOMINANT SPECIES OF THE SEMI-ARID VALLEY SCRUBS IN MAOXIAN ON THE UPPER REACHES OF THE MINJIANG RIVER

采用２×２列联表，通过方差分析、Ｘ２检验、Ｏｃｈｉｎｉ关联指数和Ｐｅａｒｓｏｎ积矩相关系数，分别对岷江上游茂县半干旱柯谷灌丛的１０个主要优势种的种间关联和种间协变进行了定量分析．研究结果表明：茂县半干旱河谷灌丛的优势种间关系较复杂．多物种间里显著的复合正相关关系，４５个种对中的７个种对具有显著的正关联，其关联程度较高（Ｏｃｈｉａｉ指数为０．６４５～０．８５８），这些关联的种对分别对环境的要求相同；５个种对存在显著的正协变，它们都是非显著关联的种对，表明在某一具体的植被类型中，种间关联与协变并无明显的内在联系．小角柱花（Ｃｅｒａｔｏｓｔｉｇｍａｍｉｎｕｓ）与其它优势种间的关联性最广泛，而刺族花（Ｃｏｎｖｏｌｖｕｌｕｓｔｒａｇａｃａｎｔｈｏｉｄｅｓ）则无显著的关联和协变，是一个相对独立的成分．

Using the methods Of 2 × 2 continsency table, variance analyses, X￣2-test, Ochiai indexes and the Pearson product-moment correlation coefficients,the authors of this paper studied the interspecific association and covariation of 10 dominant special of the semi-arid valley scrubs in Maoxian on the upper reaches of the Minjiang River. The results indicated that the interspecific relationship of the scrubs was complicated; positive complex correlation among the dominant species was obvious in the scrubs; seven pairs of species obviously showed their positive correlation in the 45 pairs of specier ; their Ochiai indexes were 0. 645～ 0. 858 , which indicated that all the specier pairs had the same demands on habitats and 5 pairs obviously showed their positive covariation. Those above proved that there was no internal relation between interspecific association and covariation in a given vegetation. The association between Ceratostigma minus and other dominant species was the most extensive. Convolvulus tragacanthoides was a relative independent component, and it was not obviously associated and correlated with other dominant species in the semi-arid valley scrubs.