伏牛山自然保护区植物功能群组成种的生态位研究
A Study on Niches of Species Constituting Plant Functional Groups on the South Slope of the Funiu Mountain
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摘要: 基于对河南省伏牛山自然保护区南坡森林生态系统的样地调查,以物种的重要值为指标,将伏牛山南坡森林生态系统按环境梯度划分为8个植物功能群。应用Levins生态位宽度公式和相似性百分率公式对组成8个植物功能群的7种主要乔木、14种主要灌木、4种主要草本种群进行了生态位宽度和生态位重叠计算与分析。结果表明:⑴重要值大的种群一般具有较宽的生态位,生态位重叠与生态位宽度有关,较宽的生态位常伴随着较高的生态位重叠。⑵高生态位重叠可能是生境斑块化和空间异质性的结果。⑶环境梯度上生态位宽度的变化,反映了功能群组成种对环境适应性和资源利用能力的变化,并最终导致植物功能群组成的变化。Abstract: The forest ecosystem on south slope of the Funiu Mountain was investigated by using community ecological techniques.Data thus collected were used to calculate importance values of the plant species,which were in turn used to designate eight plant functional groups(PFGs).Employing respectively Levin’s formula and the percentage of similarity formula,we calculated niche breadths and overlaps of 7 species of trees,14 species of shrubs and 4 species of herbs populations constituting the PFGs.The results showed that:(1)Species of high importance values usually had relatively bread niches,which were frequently accompanied by high levels of niche overlap;(2)High levels of niche overlap could result from patchiness and heterogeneity of suitable habitats;(3)Niche breadth variations along the altitudinal(precipitation and temperature)gradients reflected changes in the ability of the species constituting PFGs to adapt to different environments and exploit different resources,these changes would eventually lead to shifts in PFG compositions.