呼伦贝尔草地风蚀沙化地土壤种子库多样性研究  

Study on Diversity of Soil Seed Banks of Wind Erosion Sandy Land in Hulunbeier Steppe.

作　　者：吕世海[1] 卢欣石[1] 曹帮华[1] 

机构地区：[1]北京林业大学资源与环境学院

出　　处：《中国草地》2005年第3期5-10,共6页Grassland of China

基　　金：国家"十五"科技攻关项目"农田草地风蚀沙化防治技术"(2002BA517A-10);农业部草地资源与生态开放实验室共同资助

摘　　要：采用野外定点取样与室内培养相结合的方法,研究了呼伦贝尔4种退化沙地土壤种子库密度多样性。结果表明:土壤种子库密度随草地沙化程度的加重而下降,且不同沙化阶段其下降率各异,从固定沙地到半固定、半流动、流动沙地,土壤种子库密度分别下降75.7%、83.4%和84.2%。种子库物种数的变异从固定沙地到半流动沙地变化较小,而到流动沙地变化较大,主要为一二年生植物(50%),多年生草本和灌木比例相对较少。土壤种子库物种多样性指数变化与密度变化不一致,其中半固定沙地最大,流动沙地最小。种子库群落相似性指数变化幅度在0.6087～0.9355之间,说明其空间异质性较小。Based on the field sampling and the bourgeoning experiment in laboratory, the diversity of the soil seed banks in 4 types of sandy grasslands were studied. The results showed that the density of soil seed banks was respectively 9826.1±2679.8 viable seeds·m^(-2), 2385.9±222.4 viable seeds·m^(-2), 1635.5±217.4 viable seeds·m^(-2) and 1549.0±491.8 viable seeds·m^(-2), and it was decreased with the increase of desertification degree from fixed sand lands to semi-fixed sand lands, to semi-mobile sand lands and to mobile sand lands by 75.7%、83.4% and 84.2% respectively. The change of plant species in soil seed banks was smaller from fixed sand lands to semi-mobile sand lands, but it was bigger from semi-mobile sand lands to mobile sand lands. The proportion of the plant species in the soil seed banks in 4 types sandy grasslands was dominated by annuals and biennials (50%). The species diversity index of the soil seed banks did not decrease with the increase of desertification degree, and it is the smallest in the mobile sand lands, but biggest in the semi-fixed sand lands. The similarity coefficient of composition of the soil seed banks in the 4 types of sandy grasslands varied ranging from 0.6087 to 0.9355, and it had indicated that the spatial heterogeneity was low.

关 键 词：风蚀沙化地 土壤种子库密度 多样性 相似性 呼伦贝尔草地 

分 类 号：S154.4[农业科学—土壤学]