不同沙丘部位和不同结皮类型对土壤种子库的影响

采用萌发法对古尔班通古特沙漠沙垄不同部位生物结皮类型的种子库进行研究,发现不同沙丘部位和结皮类型种子分布特征有一定的规律性:藻类结皮的种子数量、丰富度和多样性均显著高于地衣和苔藓结皮。生物结皮从藻类到地衣和苔藓的演替,有降低种子数量和种子多样性的现象。在不同沙丘部位,沙丘顶部流沙的种子数量和多样性较低,与丘顶流沙相比沙丘底部的藻类结皮显示出较高的丰富度和多样性,但沙丘底部的地衣和苔藓结皮与丘顶流沙相比未表现出明显的差异。背风坡中部的藻类结皮种子多样性较高,显著高于迎风坡中部的藻类结皮。

Effects of Different Dune Positions and Microbiotic Crusts on Soil Seed Banks in the Gurbantonggut Desert

In this paper,the soil seed banks in different microbiotic crusts and at different sand dune positions in the Gurbantonggut Desert are studied using germination method.The results show that the seed density,species richness(Margalet index) and species diversity(Simpson's diversity index and Shannon-Winner index) are higher on algal crust than that on lichen and moss crusts.The seed density and diversity are decreased with the evolution from algal crust to lichen and moss crusts,and they are the lowest on the top of sand dunes without crust.The seed density and diversity of seed bank on algal crust are significantly higher than that on top sand.Comparing with the algal crust,there is no significant difference of seed density and diversity between the lichen and moss crusts and the topsoil without crust.The seed density and diversity on algal crust are significantly higher on leeward slope than that on windward slope.