Characteristics Of Soil Seed Bank In Different Sand Dune In The Eastern Of Kubuqi Desert

Using the method of substituting space for time, the species composition of aboveground vegetation and soil seed bank, vertical and horizontal distribution pattern of soil seed bank in the different sand dune(fixed dune, semi-fixed dune, semi-mobile dune, mobile dune) were studied at the eastern of Kubuqi desert, to explore succession characteristics of plant communities and their potential role in the sand dune ecology. The results showed that:(1) There were 11 families, 27 species in the aboveground vegetation. Annual herb was 58.82%, 66.67%, 57.90%, 60.00% from fixed dune to mobile dune. With the process of succession, Margalef, Simpson, Shannon-Wiener, Pielou of species in aboveground vegetation are increasing.(2) There were 11 families, 25 species in the soil seed bank. Annual herb was 78.57%, 69.23%, 52.94%, 61.54% from fixed dune to mobile dune. The soil seed bank density is increasing with the dune fixed. The density of annual herb was 96.55%, 98.30%, 95.26%, 97.15% of the total soil seed bank from fixed dune to mobile dune. With the process of succession, Margalef, Simpson, Shannon-Wiener, Pielou of species in soil seed bank are increasing.(3) With the increase of soil depth, density of soil seed bank decreased obviously(P<0.05). Density of soil seed bank in 0-5cm is 76.30%, 90.21%, 68.67%, 80.10% from fixed dune to mobile dune. The density of micro-landform soil seed bank is the following in order: windward>leeward>top, and bottom>middle>top in the fixed dune and semi-fixed dune; leeward > windward >top, and middle > bottom >top in the semi-mobile dune; leeward>windward> top, and bottom>middle>top in the mobile dune.(4)Soil bulk density, soil moisture content have a significant different with the density of soil seed bank(P<0.05).organic matter, and total nitrogen content, soluble nitrogen content, coarse dust content, medium silt content, fine silt content, and clay content have no significant different with the density of soil seed bank(P>0.05).(5) Similarity coefficients of soil seed bank and aboveground vegetation in different succession stages were less than 0.50, which were considered as having a moderate dissimilarity level. Similarity coefficients between aboveground vegetation and soil seed bank were more than 0.50, showed a moderate similarity level. Soil seed bank fall behind in aboveground vegetation...