干旱区研究

干旱区研究 ›› 2020, Vol. 37 ›› Issue (4): 881-889.doi: 10.13866/j.azr.2020.04.08

• • 上一篇    下一篇

人工固沙区植被演替过程中土壤水分时空分异特征

王 博， 段玉玺， 王伟峰， 李晓晶， 刘 源， 刘宗奇   

  1. （内蒙古自治区林业科学研究院，内蒙古 呼和浩特 010010）
  • 收稿日期:2019-10-29 修回日期:2019-12-27 出版日期:2020-07-15 发布日期:2020-10-18
  • 通讯作者: 段玉玺. E-mail：nmg.dyx@163.com
  • 作者简介:王博（1989－），男，博士，助理研究员，主要从事林业碳汇和荒漠化防治研究. E-mail：wbbrave@163.com
  • 基金资助:
    国家林业公益性行业科研专项（201404204）；林业科技创新平台项目（2019132021）；内蒙古自然科学基金项目（2017MS0368）； 内蒙古自然科学基金项目（2019MS03037）

Spatial and temporal variability of soil moisture content during vegetation succession in sand-binding areas

WANG Bo， DUAN Yu-xi， WANG Wei-feng， LI Xiao-jing， LIU Yuan，LIU Zong-qi   

  1. （Inner Mongolia Forestry Research Institute, Hohhot 010010, Inner Mongolia, China）
  • Received:2019-10-29 Revised:2019-12-27 Online:2020-07-15 Published:2020-10-18

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摘要： 以库布齐沙漠东缘人工固沙区不同植被演替阶段（演替初期、中期、后期、成熟期）的沙地为研究对象，对 2017、2018年生长季沙地迎风坡顶部、中部和底部0～180 cm土壤分层测定体积含水量，阐明荒漠土壤水分时空分异特征及其对环境因子的响应。结果表明：因降水量的差异导致研究区土壤含水量存在年际变化，2018 年（8.8%）＞2017年（4.8%）；受降水事件和植物生长的影响，4种样地土壤含水量均具有生长季初期缓慢下降、生长旺盛期降水补给后快速增大、生长季末期稳定积累的阶段特征；不同植被演替阶段土壤含水量整体表现为演替初期（7.3%）＞成熟期（7.2%）＞后期（6.7%）＞中期（5.9%）；4种样地均为迎风坡中部土壤含水量最低，坡顶和坡底含水量在不同演替阶段各有高低；4种样地土壤含水量均呈现随土层加深含水量先降低后增大的动态趋势，表层0～20 cm土层含水量显著高于其他各层，深层土壤存在水分变化拐点，是含水量最低的干沙层，在不同演替阶段或降水量下干沙层出现的深度会发生变化。在生长季末期，通过一季的消耗与补给，研究区内土壤水分储量呈正向平衡，可以满足人工固沙植被正常生长和演替所需水量。

关键词: 人工固沙区, 土壤含水量, 植被演替, 时空变化, 库布齐沙漠

Abstract: Experiments were conducted by taking sandy soil at different stages of vegetation succession（primary stage, middle stage, later stage, and maturation stage of succession）in the eastern Hobq Desert, China, as a sand-binding area. Soil volumetric moisture content from 0 to 180 cm of the top, middle, and bottom of the windward slope of sandy land was measured from during the growing season between 2017 and 2018. This study aimed to investigate the spatiotemporal dynamic characteristics of soil moisture content and reveal the response of desert soil moisture content to environmental factors. The results showed that precipitation differences caused annual fluctuation of average soil moisture content in the study area; 2018（8.8%）> 2017（4.8%）. Affected by precipitation and plant growth, the soil moisture content in the four sample plots showed obvious seasonal variations. Moisture content decreased slowly in the early growing season, increased rapidly after replenishment with precipitation during the intense growing season, and remained constant at the end of the growing season. Soil moisture content at different vegetation succession stages is generally shown as primary stage（7.3%）>maturation stage（7.2%）>later stage（6.7%）>middle stage（5.9%）. Soil moisture content in the middle of the windward slope was the lowest in all four sample plots. Soil moisture content in the top and bottom layers varied in different succession stages. The soil moisture content of four sample plots showed clear vertical changes, decreasing first and then increasing with soil depth. The moisture content of the surface layer（0-20 cm）was significantly higher than that of the other layers. There was an inflection point in the moisture content of the deep soil in each sample plot, which was the dry sand layer with the lowest moisture content. The depth of the dry sand layer changed at different succession stages or precipitation conditions. At the end of the growing season, the precipitation supply and vegetation consumption of soil moisture in the study area reached a positive balance. Besides, the soil moisture storage was able to sustain the normal growth of artificial vegetation in the sand-binding area.

Key words: sand-binding area, soil moisture content, vegetation succession, spatiotemporal variations, Hobq deser