黄土高原农田与草原土壤种子库

为了比较黄土高原农田与草原土壤种子库之间的关系，探讨黄土高原的农业生产结构，本研究采用发芽试验法对黄土高原不同土地利用方式(农田、撂荒地、封育天然草地)下的0-10 cm土层的土壤种子库密度与组成进行了分析。结果表明，农田的土壤种子库的平均密度是1 455粒m-2，共有7个物种；撂荒地的土壤种子库平均密度为1 008粒m-2，共有3个物种；封育草地的土壤种子库密度为5 044粒m-2，共有12个物种。对土地的不合理利用导致的撂荒地的土壤种子库密度、多样性、丰富度均最低，土壤沙化严重。封育草地的土壤种子库密度、多样性和丰富度均最高，土壤种子库在一定程度上对地表植被恢复和更新有着重要作用。因此，在生态环境脆弱的黄土高原地区改变传统的农业结构，增加草地封育年限，增加牧草种植，进而增加地表植被的密度、多样性和丰富度，从而改善生态环境。

Soil seed banks of cropland and rangeland on the Loess Plateau

In order to compare the relationship between soil seed banks of cropland and rangeland on the Loess Plateau, and to explore the agricultural production structure of the Loess Plateau, the present article studied the density and composition of soil seed banks in 0 to 10 cm soil layer under different utilization using germination experiment. The results showed that average density of soil seed for cropland, abandoned land and enclosure rangeland was 1 455 seedsm-2, 1 008 seedsm-2 and 5 044 seedsm-2, respectively, with a total of 7 species, 3 species and 12 species, respectively. Due to unreasonable usage of land resource, the density, diversity and richness of soil seed banks for abandoned land were the lowest with serious soil desertification. Enclosure rangeland had the highest soil seed density, diversity and richness which suggested that soil seed banks in a certain extent played an important role on the surface vegetation restoration and update. Therefore, the traditional agriculture structure of the Loess Plateau area with fragile ecological environment should be changed to increase grass nurture and enclosed time, which in turn increase the density, diversity and abundance of surface vegetation, and then improve the ecological environment.