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草业学报 ›› 2015, Vol. 24 ›› Issue (9): 197-205.DOI: 10.11686/cyxb2015083

• 研究简报 • 上一篇    下一篇

高寒草甸草地微斑块植物特征及其土壤性质的研究

石明明1,张永超1,张典业1,任运涛1,宗文杰2,傅华1,牛得草1,*   

  1. 1.草地农业生态系统国家重点实验室,兰州大学草地农业科技学院,甘肃 兰州 730020;
    2.甘肃省玛曲县畜牧兽医局,甘肃 甘南 747300
  • 收稿日期:2015-02-20 出版日期:2015-09-20 发布日期:2015-09-20
  • 通讯作者: E-mail:xiaocao0373@163.com
  • 作者简介:石明明(1990-),男,甘肃天水人,在读硕士。E-mail:734341754@qq.com
  • 基金资助:
    公益性行业(农业)科研专项经费(201203041),“长江学者和创新团队发展计划(IRT13019)”,国家科技支撑项目(2012BAD13B05)和国家自然科学基金(31201837,31172258)资助

Plant traits and soil properties in pasture mini-patches in an alpine meadow

SHI Ming-Ming1, ZHANG Yong-Chao1, ZHANG Dian-Ye1, REN Yun-Tao1, ZONG Wen-Jie2, FU Hua1, NIU De-Cao1, *   

  1. State Key Laboratory of Grassland Agro-ecosystem, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
  • Received:2015-02-20 Online:2015-09-20 Published:2015-09-20

摘要: 植物群落的斑块化与维持是草地对外界干扰的响应,也是植物群落及其生物多样性持续发展的基础。分析了3个不同鼠洞数量梯度下斑块种类、数量、面积的变化和中度鼠洞数下5种主要斑块植物群落的结构及其土壤性质。结果表明,在中度鼠洞数下,斑块的种类和总数量最高;斑块的总面积随鼠害的加重呈增加趋势;从中度到重度梯度上,鹅绒委陵菜、黄帚橐吾和草玉梅斑块的数量和面积都增加,且面积增大剧烈,乳白香青和火绒草等斑块的数量和面积都减小,具有消失的趋势;在重度鼠洞数量下草地微斑块表现为由少数起主导作用的斑块组成,斑块格局变的较为简单。斑块中单一物种生物量的变异性增加是斑块最主要的特征,这种单一物种的大量繁殖影响着斑块中植物的功能群结构和物种的多度,从而通过不同形式对干扰产生缓冲作用。植物群落的斑块化影响着土壤的异质性,对不同斑块土壤性质进行主成分分析,除乳白香青和基质斑块,其余4种斑块土壤都具有较低的全氮、碱解氮、速效磷,且不同斑块间土壤全氮、碱解氮和速效磷的变异系数都较高,可见,土壤全氮、碱解氮和速效磷的含量以及空间异质性在响应植被的演替上较敏感,因此,高寒草甸生态系统中维持全氮和速效养分资源的供应对维持生态系统的稳定具有重要的意义。

Abstract: The patchiness and persistence of plant communities represent grassland responses to outside disturbance, and are the basis of sustainable development of plant communities and biodiversity. The aim of this study was to understand the factors contributing to the maintenance and development of plant communities and the effects of patchiness on soil properties after a disturbance. The changes in the types, number, and areas of mini-patches in meadows were evaluated in meadows with a light, moderate, and heavy density of plateau pika (Ochotona curzoniae) burrows. The plant community structure and soil properties were evaluated for five types of patches in meadows with a moderate number of burrows. Some mini-patches were characterized by a high abundance of a single species, with mini-patch areas ranging from 0.5 m2 to 100 m2 in an alpine meadow (not including background patches). These types of patches were named according to the main plant species. We chose three approximately 1-hectare sample sites with different burrow densities; light, moderate, and heavy. Three quadrats (20 m×20 m) were placed randomly to determine the types, number, and area of patches within each site. We chose five types of patches from the three sample sites, and selected three typical patches for each type to determine the plant community structure and soil properties. Quadrat sampling (1 m×1 m) was used to determine basic plant traits (composition, height, cover degree, above-ground biomass of vegetation) and soil properties (organic carbon, pH, total nitrogen, available nitrogen, total phosphorus, available phosphorus) in the patches. The meadows with moderate burrow density had the most types of patches and the greatest abundance of patches. The total area of patches tended to increase with greater deterioration caused by plateau pika. The number and areas of Potentilla anserine, Ligularia virgaurea, and Anemone rivularis patches tended to increase, and their areas increased dramatically from the moderate to heavy burrow density. The number and areas of Anaphalis lacteal and Leontopodium japonicum patches tended to decrease, and these patches tend to disappear from as the burrow density increased from moderate to heavy. There were few main types of pasture mini-patches, and the pattern of patches was relatively simple under heavy burrow density. An abnormal increase in the biomass of a single species was the main characteristic of the patches. The expanding propagation of single species affected the structures of plant functional groups and species abundance, and thus, cushioned the effects of other types of disturbance. The results of the principal component analysis showed that the amounts of total nitrogen, available nitrogen, and available phosphorus in soil were lower in four types of patches than in A. lacteal patches and background patches. The coefficients of variation were higher for soil total nitrogen, available nitrogen, and available phosphorus than for other soil properties in patches in the meadows with moderate burrow density. The contents and spatial heterogeneity of soil total nitrogen, available nitrogen, and available phosphorus were more sensitive than the responses of vegetation succession to plateau pika activity. Therefore, it is very important that the supply of total nitrogen and available nutrients are maintained to retain the stability of the alpine meadow ecosystem.