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高山嵩草草甸初级生产力、多样性与土壤因子的关系

2016-01-28石红霄侯向阳师尚礼吴新宏李鹏杨婷婷

草业学报 2015年10期

石红霄,侯向阳*,师尚礼,吴新宏,李鹏,杨婷婷

(1.甘肃农业大学草业学院, 草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,

甘肃 兰州 730070; 2.中国农业科学院草原所,内蒙古 呼和浩特 010010)

高山嵩草草甸初级生产力、多样性与土壤因子的关系

石红霄1,2,侯向阳1,2*,师尚礼1,吴新宏2,李鹏2,杨婷婷2

(1.甘肃农业大学草业学院, 草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,

甘肃 兰州 730070; 2.中国农业科学院草原所,内蒙古 呼和浩特 010010)

摘要:为了揭示高寒草甸初级生产力与土壤因子及多样性指数的关系,本文选择青藏高原三江源区具有代表性的高山嵩草矮嵩草草地型、高山嵩草杂类草草地型和高山嵩草圆穗蓼草地型,进行植物多样性、生产力及土壤养分的分析研究。结果表明:不同类型高山嵩草草甸生物量、群落多样性、土壤理化性质都存在显著差异(P<0.05),其中高山嵩草圆穗蓼草地生产力最高,物种数最多,土壤营养成分含量最高。相关性分析表明:地上生物量及优良牧草生物量与土壤理化性质呈显著相关(P<0.05),优良牧草生物量与土壤有机质呈极显著正相关(P<0.01)。物种数的多寡与土壤养分呈显著相关(P<0.05),而群落结构的均匀度及多样性是与植物都需要的大量元素钾呈正相关的(P<0.01)。优势物种的竞争能力是通过土壤的有限养分(速效磷)体现的,两者呈显著正相关(P<0.05),因而地上生物量及优良牧草生物量与速效磷呈极显著正相关(P<0.01)。而矿物氮(包含碱解氮)对丰富度指数、初级生产力有不可替代的作用。

关键词:高寒草甸;初级生产力;多样性;土壤理化性质

Relationships between plant diversity, soil property and productivity in an alpine meadow

SHI Hong-Xiao1,2, HOU Xiang-Yang1,2*, SHI Shang-Li1, WU Xin-Hong2, LI-Peng2, YANG Ting-Ting2

1.CollegeofPrataculturalScience,GansuAgriculturalUniversity,KeyLaboratoryofGrasslandEcosystem,MinistryofEducation,Sino-U.S.CentersforGrazingLandEcosystemSustainability,Lanzhou730070,China; 2.GrasslandResearchInstituteofChineseAcademyofAgricultureScience,Hohhot010010,China

Abstract:The relationships among primary productivity, soil factors and plant diversity in alpine meadows were investigated by analyzing plant community diversity, productivity and soil nutrients of three grassland types in the Three Rivers District, Kobresia pygmaea+Kobresia humilis, Kobresia pygmaea+forbs and Kobresia pygmaeaPolygonum macrophyllum meadow. The biomass, community diversity and soil physical and chemical properties of the different alpine meadows types differed significantly (P<0.05). The Kobresia pygmaea+P. macrophyllum meadow had the highest productivity, number of species and soil nutrient content. Correlation analysis showed that forage biomass and soil physical-chemical properties (P<0.05) and soil organic matter (P<0.01) were significantly positively correlated. The number of plant species present was also correlated with soil nutrients (P<0.01), while uniformity and diversity of community structure were positively correlated (P<0.01) with soil potassium content. The competitive advantage of dominant species was associated with tolerance of low fertility(P<0.05), particularly phosphorus. Aboveground biomass and forage biomass and available phosphorus were significantly positively correlated (P<0.01). Nitrogen was associated with species richness and productivity.

Key words:alpine meadow; primary productivity; community diversity; soil properties

生物多样性、生产力与土壤因子的关系对揭示生物多样性与生态系统功能的关系有重要意义[1]。土壤性质的变化直接影响着植被的生长、发育及演替过程[2],同样,植被的变化也改变着土壤的特征。因此,从植被与土壤环境的关系入手,研究高山嵩草草甸不同植被类型群落生产力和土壤环境的变异规律以及二者的相互关系,对区域可持续发展和促进退化高寒草甸的恢复具有指导意义。有关生物多样性、生产力与土壤因子关系的研究多涉及森林群落[3]、草原群落[4]、高寒草甸群落等[5-6],但对不同类型高寒草甸群落物种多样性、生产力与土壤特性定量关系的研究较少。……

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