毛乌素沙地东南缘沙柳群落种子库特征研究

Seed Bank Characteristics of Salix Community in Southeastern Margin of Mu Us Sandy Land

土壤种子库是毛乌素沙地生态系统的重要组成部分,对区域植被演替与高质量恢复具有重要意义。采用野外调查与室内种子萌发试验相结合的方法,分析毛乌素沙地东南缘沙柳群落土壤种子库的物种组成、萌发特征及其与地上植被的物种相似性。结果表明:1)沙柳群落种子库拥有13种,11属,7科,其中小画眉草、虫实和早熟禾占比分别为32.20%、24.6%和16.4%。2)沙柳群落种子库物种易萌发,试验发现,土壤种子库萌发时滞1~2 d,萌发历时24~39 d,7 d内50%的种子萌发,14~17 d 90%的种子萌发。多样性高(Margalef丰富度指数D为2.303,Shannon-Wiener多样性指数H′为1.896,Pielou均匀性指数J为0.739,Whittakerβ多样性指数为13)。3)土壤种子库Czekanowski群落相似性系数为0.571,适宜通过土壤种子库来辅助沙柳群落的植被建设。期望为毛乌素沙地植被高质量建设提供科学支撑。

Soil seed bank is an important part of the ecosystem of Mu Us sandy land,which is of great significance to regional vegetation succession and high quality restoration.In this study,the species composition,germination characteristics and the species similarity with the aboveground vegetation of the soil seed bank of Salix community in the southeast margin of Mu Us sandy land were analyzed by combining field investigation and indoor seed germination test.The results showed that 1)there were 13 species,11 genera and 7 families in the soil seed bank of Salix community.2)The species in the soil seed bank of Salix community were easy to germinate and had high diversity(Margalef richness index D:2.303,Shannon-Wiener diversity index:1.896,Pielou evenness index J:0.739,and Whittaker diversity index:13).3)Obvious heterogeneity existed in the spatial distribution of soil seed bank.The similarity coefficient of Czekanowski community was 0.571,indicating that the soil seed bank is suitable for assisting the vegetation construction of Salix community.It is expected to provide scientific support for high-quality vegetation construction in Mu Us sandy land.