祁连山东段干旱草原2种群落物种构成及稳定性研究

发布时间：2018-11-03 21:51

【摘要】：芨芨草作为干旱、半干旱草原建群种,其群落植被构成和稳定性影响草原荒漠化程度,研究其群落物种构成及稳定性,可表征草原演替动态和发展方向。该研究以甘肃天祝松山滩干旱草原芨芨草群落和针茅群落为对象,定量分析其群落物种组成和多样性、功能群生物量构成、Raunkiaer频度和种间Spearman秩相关,探究物种构成和种间关联与群落稳定性的关系。结果表明:(1)针茅群落物种多样性较芨芨草群落丰富,其物种更替程度相近。(2)2个群落均处于退化状态,随退化程度加剧,丛生禾草和杂类草分别占据芨芨草群落和针茅群落主要地位。(3)2个群落主要植物种对的正负关联比皆小于1,其植物种间联结性松散,群落稳定性较低。(4)高物种多样性不利于针茅群落稳定。研究认为,群落功能群构成及其均匀度和干旱扰动比多样性对群落稳定性影响更大。
[Abstract]:Achnatherum splendens, as a species of arid and semi-arid grassland, its community vegetation composition and stability affect the degree of grassland desertification. The study of species composition and stability of the community can characterize the succession dynamics and development direction of grassland. In this study, the community of Achnatherum splendens and Stipa arundinacea in the arid steppe of Songshan Beach, Gansu Province was studied. The species composition and diversity of community, the biomass of functional group, the frequency of Raunkiaer and the rank of Spearman among species were quantitatively analyzed. To explore the relationship between species composition, interspecific association and community stability. The results showed that: (1) the species diversity of Stipa arundinacea community was richer than that of Achnatherum splendens community, and its species replacement degree was similar. (2) the two communities were in a degraded state and increased with the degradation degree. Clump grasses and hybrid grasses occupied the main position of Achnatherum splendens community and Stipa arundinacea community respectively. (3) the positive and negative correlation ratio of the two main plant species pairs was less than 1, and the association between the two species was loose. (4) High species diversity is not conducive to the stability of Stipa arundinacea community. The results showed that the composition of community functional group and its evenness and drought disturbance had more influence on community stability than diversity.
【作者单位】：兰州大学草地农业科技学院;
【基金】：国家重点研发计划课题(2016YFC0501902)
【分类号】：S812

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