黄土高原半干旱区天然草地群落结构与土壤水分关系  

Plant community structure and soil moisture in the semi-arid natural grassland of the Loess Plateau

作　　者：张志南[1] 武高林[2,3] 王冬[3] 邓蕾[2] 郝红敏[2] 杨政[2] 上官周平[2,3] 

机构地区：[1]西北农林科技大学农学院,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100 [3]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《草业学报》2014年第6期313-319,共7页Acta Prataculturae Sinica

基　　金：国家自然科学基金(41371282);中国科学院战略性先导科技专项(XDA05050403);中国科学院西部行动项目(KZCX2-XB3-13)资助

摘　　要：气候变化导致水热条件发生变化,从而引起土壤含水量改变,必然影响区域植物群落结构和功能。本研究以黄土高原半干旱区天然草地群落为研究对象,在较大空间尺度上根据随机设置样地法调查区域内典型地带性草地群落,研究黄土高原半干旱区土壤含水量的变化对草地群落的影响。结果表明,1)地上生物量、凋落物质量与土壤含水量呈显著正相关;地下生物量和总生物量与土壤含水量虽正相关但不显著;2)物种多样性和物种丰富度均随着土壤含水量的增加而增加;3)植物功能群受土壤水分的影响,表现为禾本科和豆科随着土壤含水量的增加而增加,而杂类草相反。总之,在半干旱区土壤水分是限制群落生产力和物种多样性的重要因子,而禾本科和豆科作为指示物种可以反映土壤的水分状况。土壤水分的变化可能是导致半干旱区天然草地群落演替的驱动力,草地退化可能与土壤含水量的改变有关。Climate change has resulted in altered hydrothermal conditions and variation in soil moisture content which affects plant community structure and function on the Loess Plateau.The effect of soil water on the plant community in the semiarid natural grassland of the Loess Plateau was investigated using a large scale randomized design trial.Key results were：1）Above-ground biomass and litter biomass were significantly positively correlated with soil water content.2）Plant diversity and species richness were significantly positively correlated with soil moisture.3）Plant functional groups were also affected by soil water content;both grass and legume species increased significantly with increase in soil water content,whereas forbs decreased significantly.It was concluded that soil moisture is one of the most important factors limiting community productivity and plant species diversity.Additionally,grass species may be able to indicate or reflect soil moisture status.Soil moisture changes may be driving plant community succession in semi-arid grassland.

关 键 词：天然草地 土壤水分 生物量 物种多样性 半干旱区 

分 类 号：S812[农业科学—草业科学]