放牧和围封条件下草地土壤种子库特征研究

Characteristics of Soil Seed Bank Between Grazing and Enclosed Grasslands

通过对比研究放牧草地、围封5年和10年草地,分析土壤种子库的种类组成、多样性特征以及种子库物种与地上植被的关系,揭示辽宁彰武地区草地围封后的土壤种子库特征。结果表明:放牧草地土壤种子库植物种数为9种,密度为(6573.15±210.14)粒·m-2;围封5年和10年草地种子库植物种数分别为9种和6种,密度分别为(9987.25±255.01)粒·m-2和(14675.16±535.72)粒·m-2。放牧草地土壤种子库群落中以1年生杂类草居多,围封草地则以多年生禾本科牧草和豆科牧草为优势种。放牧和围封5年、10年草地土壤种子库的丰富度指数分别为0.91,0.87和0.52,物种多样性指数呈现相同的变化趋势。3个样地土壤种子库与其地上植被之间相关性较低。

Through analysis of the soil seed bank species composition, diversity and relationship between species composition of seed banks and standing vegetations, the characteristics of soil seed banks of grasslands was studied after enclosure in Zhangwu region of Liaoning Province. The results showed that 9 plants species were found in grazing grassland and the density of seed bank was 6573.15 seeds·m^-2 There were 9 and 6 plants species in seed banks of degraded grasslands enclosure after 5 years and 10 years respectively, where the densities of seed banks were followed by 9987.25 and 14675.16 seeds·m^-2. Dominant species of soil seed bank community in grazing grassland were annual weeds, while in enclosed grasslands there were perennial grasses and perennial leguminous grasses. Richness index of soil seed banks in grazing and degraded grasslands enclosure after 5 years and 10 years were 0.91, 0.87and 0.52, respectively. Diversity index had the same tendency with richness. There was no significant correlation between seed banks and standing vegetations among 3 plots.