聂荣县不同程度退化草地土壤种子库特征研究

Investigation on the Characteristics of Soil Seed Bank in Different Degree Degenerated Grassland in Nierong County

通过研究西藏聂荣县不同程度退化草地土壤种子库物种种类、密度、分布等特征及地上植被群落的物种组成,探讨了地上植被与土壤种子库之间的关系及种子库在地上植被群落构建中的作用,研究结果表明:中度退化样地土壤种子库密度最高,重度退化草地土壤种子库密度最低。未退化与轻度退化样地土壤种子库物种种类以高山嵩草和矮生嵩草等莎草科植物为主,中度退化样地土壤种子库物种种类以蔷薇科委陵菜为主,各样地土壤种子库主要集中在0~3 cm土层中。样地土壤种子库与植被群落相似度从高到低的顺序依次为未退化、轻度退化、中度退化、重度退化。对于中度退化草地,适当进行围封休牧;重度退化草地进行免耕补播将利于草地生态功能的恢复与保护,为高寒草甸的管理、高寒地区退化生态系统的恢复与重建提供参考。

This article investigated the characteristics of species,density and distribution of soil seed bank and the composition of above ground plant community in different degree degenerated grassland in Nierong county.It were discussed that the relationship between above ground plant community and soil seed bank,and the influence of soil seed bank on the construction of above ground plant community.The results showed that medium degen⁃erated grassland had highest density of soil seed bank and serious degenerated grassland had lowest density of soil seed bank.The main species of soil seed bank in non-degenerated and mild degenerated grassland is Cyperaceae,such as Kobresia Littledalei,Kobresia Pygmaea and so on.The main species of soil seed bank in medium degenerated grassland is Potentilla chinensis,which belongs to Rosaceae.The soil seed bank in different sample grassland concentrated in the 0-3cm soil layer.The sequence from high to low of similarity between soil seed bank and plant community was non-de⁃generated,mild degenerated,medium degenerated and serious degenerated.This paper suggested that adopting enclosure and rest grazing appropri⁃ately for medium degenerated grassland,carrying no-tillage and replanting for serious degenerated grassland.These suggestions will be beneficial to the restoration and protection of grassland ecologically function,and will provide reference for management of alpine meadow and recover and recon⁃struct of degenerated ecological system in alpine regions.