鹞落坪半夏生境地主要草本种群生态位特征

【目的】通过研究鹞落坪半夏Pinella yaoluopingensis生境地主要草本种群对环境的适应能力及对资源的利用状况,为保护和开发利用鹞落坪半夏资源提供指导性建议。【方法】对安徽省鹞落坪保护区特有种鹞落坪半夏生境地草本层进行调查,运用Levins和Shaanon-Wiener生态位宽度指数和Levins生态位重叠度指数,对生境地主要草本种群的生态位宽度及生态位重叠度进行定量研究。【结果】鹞落坪半夏生境地17个主要草本种群中,多数草本种群生态位宽度较大,其中,金星蕨Parathelypteris glanduligera、臭草Melica scabrosa、博落回Macleaya cordata生态位宽度居前3位,它们也是鹞落坪半夏生境地草本层的优势种,生态位宽度居最后3位的是荩草Arthraxon hispidus、待宵草Oenothera stricta、一年蓬Erigeron annuus,鹞落坪半夏生态位宽度居中下水平。主要草本种群的重要值(IV)与生态位宽度B_i、B_i'呈极显著正相关,相关系数分别为0.807(Sig.=0.000)、0.707(Sig.=0.002)。生态位重叠值在0.4以下的种对占所有种对的83.46%,其中生态位重叠值为0的种对占38.60%,而生态位重叠值1.0的种对仅占总物种种对的1.10%,各种对间的生态位重叠指数并未与相应种群的生态位宽度呈现出相关性。【结论】鹞落坪半夏生境地主要草本种群生态学特性相似性不大,对资源的共享趋势不明显,主要草本种群能和谐地共生于群落中,但鹞落坪半夏生态位宽度并无优势,只处于伴生地位。

Niche characteristics of main herbaceous populations in habitat of Pinella yaoluopingensis

[Objective]The adaptability and resources utilization of main herbaceous populations in habitat of Pinella yaoluopingensis were studied, with an aim to provide guidance and suggestions for protecting and exploiting P. yaoluopingensis. [Method] The herb layer in habitat communities of P. yaoluopingen-sis, an endemic species in Anhui Province was investigated. The niche breadths and overlaps of main herbaceous populations in the communities were measured using Levins-niche breadth, Shaanon-Wiener-niche breadth and Levins-niche overlap indices. [Result]Among all 17 main herbaceous populations in habitat communities of P. yaoluopingensis, the niche breadths of most populations were wide. Parathe-lypteris glanduligera, Melica scabrosa and Macleaya cordata had the widest niche breadth, meanwhile, they were also the dominant populations of the herb layer. Arthraxon hispidu, Oenothera stricta and Erig-eron annuus had the narrowest niche breadth, followed by P. yaoluopingensis. The important values and niche breadth Bi, Bi′of main populations were highly significantly correlated, and the correlation coeffi-cients were 0. 807 ( Sig. =0. 000 ) and 0. 707 ( Sig. =0. 002 ) respectively. Of all population pairs, the population pairs whose niche overlap values were below 0. 4 accounted for 83. 46%, the population pairs whose niche overlap values were 0 accounted for 38. 60%, but the population pairs whose niche overlap values were above 1. 0 only accounted for 1. 10%. There was no direct relationship between niche breadths and niche overlaps of main herbaceous populations. [Conclusion]There is little similarity in ec-ological characteristics for main herbaceous populations in habitat of P. yaoluopingensis. There is no ob-vious tendency in resource sharing—the main herbaceous populations grow in the communities harmoni-ously, but there is no advantage in niche breadth for P. yaoluopingensis which is in associated status.