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作 者 ：马晓勇;上官铁梁;*;张 峰;

期 刊 ：植物研究 2006年 27卷 5期 页码：610-617

关键词：恒山南北坡植被；建群种；生态位宽度；生态位重叠；

Keywords:vegetation of both slopes of Hengshan, constructive species niche breadth, niche overlap,

摘 要 ：在中国植被分区上，山西恒山是温带草原地带与暖温带落叶阔叶林地带的交错区。本文采用Shannon-Wiener 生态位宽度指数将南北坡群落的建群种群分别划分为3个生态类群。南坡的山蒿、小红菊、披针叶苔草、地榆，北坡的披针叶苔草、山菊、硬质早熟禾、麦瓶草、地榆占据较宽的生态位，生态位泛化比较明显。而南坡的鹅绒委陵菜、三裂叶绣线菊、虎楱子、沙棘，北坡的长芒草、碱茅、山蒿、珠芽蓼、铃铃香、三裂叶绣线菊、沙棘、青杨占据较窄的生态位，这与种群所处的具体生境密切相关。南坡16个建群种群构成的240个种对中有100个种对表现出生态位重叠，占整个种对的41.9%，表明恒山南坡16个种群间具有比较显著的生态位重叠。北坡21个建群种构成的420个种对中69个种对有生态位重叠，占整个种对的16.4%，说明这21个种群并不表现出显著的生态位重叠，各种群间生态位明显分离，说明不同种群利用资源的差异性比较显著。这主要是由于恒山南坡山势平缓，而北坡陡峭，南坡植被呈连续性分布，而北坡植被由于海拔高差大，植被垂直带谱中经常有断带现象，所以，生态位重叠现象比较少见。通过对南北坡建群种群的生态位宽度和生态位重叠的整体比较，可以比较客观的确立恒山作为温带草原地带与暖温带落叶阔叶林地带的分界。

Abstract:Heng Mts., Shanxi is located in the ecotone of temperate grassland zone and warm-temperate deciduous broad-leaved forest zone according to China Vegetation Regionalization. Adopting Shannon-Wiener,the niche breadth index, the article classified constructive species on both slopes into 3 ecologic groups respectively. Artemisia brachyloba, Dendranthema chanetii, Carex lanceolata and Sanguisorba alpina of the south slope, and Carex lanceolata, Denfranthema zawwadskii, Poa sphondyloes,Siline jenisseensis and Sanguisorba alpina of the north slope occupy a broader niche, showing an apparent niche generalization. By contrast, Potentilla anserine, Spiraea trilobata, Ostryopsis davidiana and Hippophae rhamnoides subsp. sinensis of the south slope, Stipa bungeana, Puccinellia distans, Artemisia brachyloba, Polygonum viviparum, Anaphalis hancockii, Spiraea trilobata, Hippophae rhamnoides subsp. sinensis and Populus cathayana of the north slope occupy a much narrower niche, which is closely related to their environment. The 16 constructive populations of the south slope form 240 species counterparts, among which 100, that’s 41.9% of the total, have niche overlaps, indicating that there exits niche overlap among the 16 species of the south slope. The 21 constructive populations of the north slope form 420 species counterparts, among which 69, that’s 16.4% of the total, have niche overlaps, indicating that there does not exit an apparent niche overlap among the 21 species. The apparent separation in ecologic niche among populations suggests a significant difference as to their utility of recourses. All of the above are caused by the evenness the south slope while the sheerness the north, which leads to a continuous spreading of vegetation on the south and many discontinuities making overlap an rare occurrence on the north because of much sharper rise of elevation. By an overall comparison and contrast of niche breadth and niche overlap of the constructive species of each slope, an establishment of Hengshan Mts. as the borderline between temperate grassland zone and warmtemperate deciduous broad-leaved forest zone can achieved more objectively.

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