土壤种子库对漫溢区受损植被更新的贡献

在塔里木河下游选择两个典型漫溢区,在野外进行了土壤种子库萌发试验,并与河水漫溢区的幼苗库进行比较,以确定土壤种子库对受损植被更新的贡献度.结果表明：两个漫溢区土壤种子库物种数均为12种,生活型组成以多年生草本和灌木为主;种子库密度分别为282.5和173.2粒·m^-2,表层土壤(0～2 cm)种子密度分别占总密度的76.9%和71.0%.土壤种子库对实生幼苗的物种组成和密度具有显著影响,两个漫溢区实生幼苗数量分别有84.7%和99.4%来源于土壤种子库.两个漫溢区土壤种子库与实生幼苗库物种相似性系数分别为0.72和0.63；实生幼苗密度与种子库密度具有很好的正相关性,说明土壤种子库对植被更新具有重要贡献.

Contribution of soil seed bank to the regeneration of damaged vegetation on floodplain.

A field germination experiment of soil seed bank was carried out on two typical floodplains in the lower reaches of Tarim River, and a comparison was made between the soil seed banks and corresponding seedling banks on the two floodplains, aimed to assess the contribution of soil seed bank to the regeneration of damaged vegetation. The results showed that there were 12 plant species in the soil seed banks, and the life forms were mainly perennial herbs and shrubs. The soil seed banks had a density of 282.5 seeds·m^-2 and 173.2 seeds·m^-2, and the seeds in top soil (0-2 cm) accounted for 76.9% and 71.0% of the total, respectively. The soil seed banks had significant effects on the seedlings species composition and density, and 84.7% and 99.4% of the seedlings on the two floodplains were emerged from corresponding soil seed banks. The similarity coefficient between soil seed bank and seedling bank of the two floodplains was 0.72 and 0.63, respectively, and there existed significant positive correlation between seedling density and soil seed bank density, illustrating that soil seed bank made important contribution to the natural regeneration of vegetation.