北温带湿地不同退水时间土壤种质资源结构及分布格局——以野鸭湖湿地为例

The Research on Soil Germplasm Resource Distribution in Different Periods of Water Degeneration in the North Temperate Zone Wetland:A Case Study of Yeyahu Wetland

为了研究北温带湿地不同退水时间条件下土壤种质资源的特征,在3个不同的水位条件下,通过幼苗萌发法对野鸭湖湿地近10年来退水湿地面积中土壤种子资源的分布格局进行了分析。结果表明,土壤中的种子在不同的退水时间条件下,变化明显:种子的密度在退水5～7年时达到最大值2.389×104ind./m2,在退水7～10年时最小,为1.352×104ind./m2;萌发植物的物种数量与之相一致,其中广泛分布类型植物与水生植物的萌发在退水5～7年时同样达到最大值,但萌发的湿生植物的数量在退水1～3年时,达到最大值;湿地中土壤种子在0～5cm和5～10cm分层上,萌发的物种数差异不显著,但在萌发数量上有明显分层现象。本文还结合以上研究结果,分析了在不同退水时间条件下,土壤种质资源产生差异的原因,进而讨论了土壤种子资源在湿地恢复和湿地保护过程中的重要作用。

Wetland is the unique ecosystem formed by water and land. However, the exploitation of wetland for human activities such as tourism largely reduced the area of wetland in China. Therefore, more researchers nowadays focus on the topic of wetland protection, due to its various ecological functions, for example, improving the climate and cleansing contaminated rivers. The distribution of soil germplasm resource in different periods of water degeneration is studied in this paper, and the research results may play an active role in the protection and management of the Yayahu wetland. Germination tests of three stages are used to evaluate the traits in different periods of water degeneration, mainly community structure, of the soil Germplasm Resource of Yeyahu wetland during the past ten years. The construction indicates that during different periods of water degeneration, the soil germplasm resource changes obviously. The density of germplasm resource reached the maximum of 2.389× 10^4 ind./m^2 after 5 to 7 years of degeneration, while the minimum density of 1.352 × 10^4 ind./m^2 is reached after 7 to10 years of degeneration. The same result is found about the number of the vegetation species in the different periods. But different kinds of vegetation species vary in results, and compared with other periods： 1） the amount of hygrophyte reaches the peak after 1 to 3 years of degeneration; 2） The amount of vegetation in extensive distribution reaches the record high after 5 to 7 years of degeneration. There are no significant differences in the number of species between soil depth ranges of 0-5 cm and 5-10 cm, but the differences in germination amount of different species are obvious. According to the research results of Yeyahu wetland soil germplasm resource distribution pattern, we reached below conclusions. First, the reason for the difference in soil germplasm is multifold, including the life-span of the seeds and the activity of the seeds in different period of water degenerations. However, the most important factor is the composition of the water. Second, the soil germplasm resource plays a significant role in the process of wetland restoration and protection.