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在浑善达克沙地以沙地榆为研究对象,针对60年生、46年生、30年生3种不同树龄沙地榆林进行了土壤种子库调查,研究了沙地榆土壤种子库的组成、数量及动态变化规律。结果表明:1)不同树龄沙地榆林结实量差异明显,结实量大小顺序为60年生林分>46年生林分>30年生林分,结实量分别为2101粒/m2、451粒/m2、24粒/m2;2)在整个观测期内,不同树龄沙地榆林土壤种子库内种子总数呈下降趋势。2011年9月各林分种子总数比2011年6月分别减少了75.17%、47.46%和96.15%。3)从成熟种子组成及动态变化趋势来看,60年生和30年生沙地榆林土壤中成熟种子在整个观测期内呈逐月下降趋势,46年生沙地榆土壤中成熟种子总数呈先下降后增加的趋势。2011年7月,成熟种子的比例最小,种子质量最差,2011年9月,成熟种子的比例最大,不存在腐烂虫害种子,种子质量最好。4)不同树龄沙地榆林土壤种子库种子总数分布规律基本一致,表现为枯枝落叶层>0-2cm土层>2-4cm土层。枯枝落叶层土壤种子库种子总数随时间呈持续减少的趋势,0-2cm土层和2-4cm土层土壤种子库种子总数呈先减少后增加的趋势。
In Hunshandake Sandy Land, the soil seed bank was investigated in Yulin of 60 years, 46 years old and 30 years old sandy soils. The composition and quantity of soil seed bank And the law of dynamic change. The results showed that: 1) There were significant differences in the stand density of Yulin in sandy land with different ages, with the order of 60-year-old stands> 46-year-old stands> 30-year-old stands and the standings were 2101 / m2 and 451 / m2, Grain / m2; 2) In the whole observation period, the total seed number of soil seed bank of Yulin in different ages had a decreasing trend. In September 2011, the total number of seeds in each forest decreased by 75.17%, 47.46% and 96.15% respectively compared with that in June 2011. 3) According to the composition of mature seeds and the trend of dynamic change, the mature seeds in the soil of 60 years old and 30 years old Yulin desert soil showed a month-by-month downward trend throughout the observation period. The total number of mature seeds in 46-year-old Elm sandy soil first decreased Increasing trend. July 2011, the smallest proportion of mature seeds, the worst seed quality, in September 2011, the largest proportion of mature seeds, there is no rotten pests seeds, the best seed quality. 4) The distribution of total seed number of soil seed bank in Yulin Sandy Land with different ages was basically the same, which showed that litter> 0-2cm soil> 2-4cm soil layer. The total number of seed banks in litter layer continued to decrease with time, and the total number of seeds in 0-2cm soil layer and 2-4cm soil layer first decreased and then increased.