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根据对西海镇土壤含水量、孔隙度与粒度测定,研究了沙柳树林土壤含水量和水循环等问题。结果表明,研究区在丰水年土壤上部含水量丰富,土壤0.1~1.0 m的平均含水量为21.3%,1.0 m以下水分明显不足,土壤水分具有在上部滞留的特点。大约1 m深度处土层开始出现轻度干层,1.3~1.6 m出现了中等干层,1.6 m深度以下出现了严重干层。干层发生原因一是降水量少,二是沙柳林的蒸腾消耗。该区土壤干层的发育阻隔了大气降水向地下深处的入渗,属于异常水分循环类型。该区土壤水分处于负平衡状态,指示当地正常年的降水量并不能充分满足沙柳林生长的需要。西海镇土壤蓄水量较少,易于发生生态环境的退化。该区土层0.1~1.0 m以粉砂为主,1.0 m以下是细砂为主的中砂细砂土。
According to the determination of soil water content, porosity and grain size in Xihaizhen, soil water content and water cycle of Salix psammophila were studied. The results showed that the water content in the upper part of the study area was abundant in the wet years, and the average water content of 0.1-1.0 m was 21.3%. The water content below 1.0 m was obviously insufficient, and the soil water had the characteristics of retaining in the upper part. At about 1 m depth, mild dry layer began to appear in the soil layer, medium dry layer occurred in 1.3 ~ 1.6 m and severe dry layer occurred in depth below 1.6 m. Dry layer occurs one reason is less precipitation, the second is the transpirational consumption of Salix. The development of dry layer of soil in this area obstructs the infiltration of atmospheric precipitation into the deep underground and belongs to the type of abnormal water cycle. Soil moisture in this area is in a negative balance, indicating that the normal precipitation in the local area does not fully meet the needs of the growth of Salix psammophila. Xihaizhen soil less water storage, prone to degradation of the ecological environment. The area of 0.1 ~ 1.0 m is dominated by silt, while the subsoil below 1.0 m is medium fine sand with fine sand.