亚热带湖滨沙地典型下垫面土壤水分变化

发布时间：2019-03-13 16:06

【摘要】：亚热带湖滨沙化作为南方荒漠化的一种典型类型,阐明沙化土壤水分变化规律对该地区植被恢复与重建具有重要指示意义。研究于2013年2月至2014年2月对鄱阳湖多宝湖滨沙地的土壤水分动态进行了监测,分析了不同覆被条件下沙地土壤水分在年内及极端气候条件下的动态特征。结果如下:(1)湖滨沙地土壤水分在梅雨和伏旱时期差异显著。在梅雨期及其前后,土壤水分主要受降水控制,各下垫面土壤平均含水量相对较高(0.063 cm~3/cm~3),且差异较小;而在伏旱及其后期,覆盖条件的差异起关键作用,湿地松样地的土壤平均含水量均低于0.035 cm~3/cm~3。(2)持续高温干旱天气下,浅层10cm土壤含水量迅速降低,之后维持在极低水平(0.01 cm~3/cm~3);随着深度增加,不同样地土壤含水量差异将会增强。(3)在多雨季节,17年生湿地松能有效增加土壤表层的持水能力;在干旱季节,湿地松对降水的截留及吸附作用强烈地影响土壤水分的补给量及补偿深度,当降水强度较低时,17年生湿地松样地的浅层土壤水分难以获得补给。因此,在亚热带沙地进行湿地松种植时,应增大初植密度,并且对于植株过高的湿地松林,也应采取适当措施降低其密度,以抵御愈加频发的极端干旱事件带来的风险,促使沙化地区发生持续的正向演替。
[Abstract]:As a typical type of desertification in southern China, desertification of subtropical lakeshore plays an important role in vegetation restoration and reconstruction in this area. From February 2013 to February 2014, the dynamics of soil moisture in Dobao sandy land of Poyang Lake was monitored. The dynamic characteristics of soil moisture in sandy land under different mulching conditions during the year and under extreme climatic conditions were analyzed. The results were as follows: (1) there were significant differences in soil moisture between plum rain and summer drought in lakeside sandy land. During the Meiyu period, the soil moisture was mainly controlled by precipitation, and the average soil water content of each underlying surface was relatively high (0.063 cm~3/cm~3), and the difference was small. The difference of covering conditions played a key role in summer drought and its late stage. The average soil water content of wetland pine plot was lower than 0.035 cm~3/cm~3. (2), and the soil water content of shallow layer 10cm decreased rapidly under the condition of continuous high temperature and drought. Then it was maintained at a very low level (0. 01 cm~3/cm~3); With the increase of depth, the difference of soil water content will increase. (3) in rainy season, 17-year-old Pinus elliottii can effectively increase the water-holding capacity of soil surface; In dry season, the interception and adsorption of rainfall by Pinus elliottii strongly affected the recharge and compensation depth of soil moisture. When the intensity of precipitation was low, the shallow soil moisture of 17-year-old wetland pine plot was difficult to be replenished. Therefore, when planting Pinus elliottii in subtropical sandy land, the initial planting density should be increased and appropriate measures should be taken to reduce the density of Pinus elliottii forest where the plants are too high in order to withstand the risk of the increasing frequency of extreme drought events, Promote the continuous positive succession in the desertification area.
【作者单位】：鄱阳湖湿地与流域研究教育部重点实验室地理与环境学院(江西师范大学);中国科学院地理科学与资源研究所陆地表层格局与模拟院重点实验室;江西省山江湖开发治理委员会办公室;
【基金】：江西省重大生态安全问题监控协同创新中心资助项目(JXS-EW-00) 江西省教育厅科技落地计划项目
【分类号】：S152.7

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