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草业学报 ›› 2015, Vol. 24 ›› Issue (11): 20-28.DOI: 10.11686/cyxb2015134

• 研究论文 • 上一篇    下一篇

玛曲沙化高寒草甸植被、土壤理化性质及土壤微生物数量研究

金红喜1, 2, 3, 何芳兰2, 3, 4, *, 李昌龙1, 2, 3, 韩生慧1, 3, 王强强1, 2, 3, *   

  1. 1.甘肃民勤荒漠草地生态系统国家野外科学观测研究站,甘肃 民勤 733300; 2.甘肃河西走廊森林生态系统国家定位观测研究站,甘肃 武威 733000; 3.甘肃省治沙研究所, 甘肃 兰州 730070; 4.兰州大学草地农业科技学院,甘肃 兰州 730020
  • 收稿日期:2015-03-11 出版日期:2015-11-20 发布日期:2015-11-20
  • 通讯作者: hefanglan2003@126.com
  • 作者简介:金红喜(1973-),男,甘肃榆中人,副研究员,博士。
  • 基金资助:
    国家自然科学基金项目(31160111,31360203)和甘肃省自然科学研究基金计划项目(1308RJZA267)资助

Vegetation characteristics, abundance of soil microbes, and soil physico-chemical properties in desertified alpine meadows of Maqu

JIN Hong-Xi1, 2, 3, HE Fang-Lan2, 3, 4, *, LI Chang-Long1, 2, 3, HAN Sheng-Hui1, 3, WANG Qiang-Qiang1, 2, 3, *   

  1. 1.Gansu Minqin National Field Observation and Research Station on Ecosystem of Desertification Rangeland, Minqin 733300, China; 2. Gansu Hexi Corridor Forest Ecosystem National Research Station, Wuwei 733000, China; 3.Gansu Desert Control and Research Institute, Lanzhou 730070, China; 4.College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
  • Received:2015-03-11 Online:2015-11-20 Published:2015-11-20

摘要: 对不同沙化程度高寒草甸植被特征、土壤理化性质及土壤微生物数量进行调查分析,结果表明:1)随着沙化程度的加剧,植物多样性指数、地上/地下生物量、土壤含水量及浅层土壤有机质、全氮、速效磷含量呈逐渐下降趋势,植物优势度、pH值呈增加趋势;深层土壤有机质、全氮、速效磷在轻度沙化样地上达到最高值。2)在不同沙化程度的土壤中,细菌数量最多,之后依次为放线菌、固氮菌、真菌;微生物在轻度沙化样地中的数量比其他3个样地都大。3)以土壤深层速效磷作为控制因子,偏相关关系分析显示,土壤微生物总量及土壤细菌数量变化与地上植物丰富度指数、植物生物量、地下生物量呈极显著负相关关系,而与植物地上/地下生物量之比呈极显著正相关关系;固氮菌数量与地上生物量呈显著相关关系,而真菌数量与地下生物量呈显著相关关系;除地上/地下生物量之比与土壤微生物数量之间呈正相关关系外,其余植被特征值与土壤微生物数量之间均呈现负相关关系。

Abstract: In recent years, desertification has been a serious threat to the alpine meadow ecosystem in the Maqu County of Gansu Province. To evaluate the effects of desertification on alpine meadow soil and vegetation, four types of plots with different grades of desertification were established in 2012. The vegetation characteristics, soil physico-chemical properties, and abundance of soil microbes were measured and analyzed in August 2013. At the same time, the relationship between the vegetation characteristics and soil microorganisms was analyzed. The results showed that the plant diversity index, soil moisture content, soil organic matter, total nitrogen (N), and available phosphorus (P) decreased as the degree of desertification intensified, and the plant dominance index and pH value increased conversely. The deep-soil organic matter, total N, and available P showed the highest values in the lightly desertified plots. Bacteria were the most abundant soil microorganisms in all plots, followed by actinomycetes, fungi, and then nitrogen-fixing bacteria. The lightly desertified plots had the largest number of microbes. A partial correlation analysis showed that the total quantities of soil microorganisms and bacteria were negatively related to above-ground plant richness index, plant biomass, and below-ground plant biomass, but positively related to the above-ground/below-ground biomass ratio. There were significant correlations between the abundance of nitrogen-fixing bacteria and aboveground plant biomass, and between the abundance of fungi and below-ground plant biomass. The quantity of soil microorganisms was positively related to the above-ground/below-ground biomass ratio, but negatively related to all of the other measured vegetation characteristics.