关键词: 昆虫学, RAPD技术, 分子遗传标记

Abstract: Interdune lowlands of mobile sand dunes have big soil seed bank rich in species, but the significance of this soil seed bank in vegetation restoration is little known. In this study, willow branch sandbarriers were settled on the windward slope of mobile sand dunes near the interdune lowlands in Horqin Sand to investigate the effects of the sandbarriers on the soil seed bank, seedling emergence, and plant establishment of the lowlands. In the plots within sandbarriers, the species number and density of soil seed bank were significantly higher, the seed density at the soil depth 5-10 cm accounting for 60% of the total, while that in control plots being less than 50%. The seedling emergence and establishment rates of psammophytes in the plots within sandbarriers were also significantly higher than those in control plots. Both in the plots within sandbarriers and in control plots, the seedling emergence of nonpsammophyte was less than 1 seedling·m^-2, and the plant establishment was as low as 0.1 seedling·m^-2. The correlations of seed density with seedling emergence and establishment were higher in control plots than in the plots within sandbarriers, and higher for psammophytes than for non psammophytes. In the same, the similarity coefficients of the species numbers of soil seed bank and the seedling emergence and establishment were higher in control plots than in the plots within sandbarriers, and higher for psammophytes than for nonpsammophytes. This study suggested that sandbarrier could intercept the seeds in interdune lowlands, increase the species richness and seed density of soil seed bank, and alter the spatial pattern of soil seed bank. The establishment of sandbarrier could improve the seedling emergence and establishment of psammophytes but not of nonpsammophytes.

Key words: Entomology, RAPD technique, Molecular genetic markers