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• 研究报告 • 上一篇    下一篇

科尔沁沙地不同生境土壤水分扩散率

姚淑霞1,2,赵传成1,2**,张铜会2,赵传燕3,高天鹏1   

  1. (1兰州城市学院, 兰州 730070; 2中国科学院寒区旱区环境与工程研究所, 兰州 730000; 3兰州大学, 兰州 730000)
  • 出版日期:2014-04-10 发布日期:2014-04-10

Soil moisture diffusivity in different habitats in Horqin Sand Land.

YAO Shu-xia1,2, ZHAO Chuan-cheng1,2**, ZHANG Tong-hui2, ZHAO Chuan-yan3, GAO Tian-peng1   

  1. (1Lanzhou City University, Lanzhou 730070, China; 2Cold and Arid Regions of Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 3Lanzhou University, Lanzhou 730000, China)
  • Online:2014-04-10 Published:2014-04-10

摘要:

利用水平土柱吸渗法对科尔沁沙地的沙质草地、固定沙丘和流动沙丘等3种生境0~100 cm土层土壤水分扩散率(D(θ))与土壤水分(θ)之间的关系进行了测定,研究了不同生境D(θ)及Boltzmann参数(λ)与θ的定量关系,并分析了D(θ)随生境及土壤剖面的变化规律。结果表明:(1)3种生境0~100 cm土层的土壤湿润峰迁移速率差异显著(P<0.05),且以沙质草地的最小,其次为固定沙丘,而流动沙丘的最大,平均值分别为0.38、0.97和1.60 cm·min-1;3种生境土壤湿润峰迁移速率随入渗距离均呈对数形式递减;(2)沙质草地、固定沙丘和流动沙丘0~100 cm土层的Boltzmann参数λ平均值分别为4.22、6.58和8.59 cm·min-1/2,且λθ的增加而减小;(3)沙质草地、固定沙丘和流动沙丘的D(θ)依次增大,0~100 cm的平均值分别为1.21、4.51和12.75 cm2·min-1;3种生境D(θ)随θ的变化规律都可以用经验公式D(θ)=ae拟合;D(θ)随土壤剖面的变化规律因生境不0同而有较大差异,说明科尔沁沙地不同生境及同一生境不同土层的土壤水分扩散率差异较大,且具有较高的空间异质性;(4)土壤有机质含量和粘粉粒含量对D(θ)的影响较大,且D(θ)随这2个因素的增加而减小。此外,生境类型及植物根系对D(θ)也有较大影响。
 

关键词: 共生珊瑚, 分子营养标记, 异养营养

Abstract: The relationship between soil moisture diffusivity (D(θ)) and soil moisture (θ) at 0-100 cm soil profile was measured by the horizontal infiltration method in three habitats in Horqin Sand Land, i.e., sandy grassland, fixed sand dune, and mobile sand dune. Also, the relationship between D(θ) and Boltzmann parameter (λ) and θ, and the changes of D(θ) across the soil profile for each habitat were considered in this study. The results showed that (1) there was a significant difference in the moving rate of soil wetting front among the three habitats, and the average rate values were 0.38, 0.97 and 1.6 cm·min-1, for the sandy grassland, fixed sand dune, and mobile sand dune, respectively. The moving rate for the three habitats all decreased with increasing in infiltration distance in a logarithmic function. (2) The λ values for the soil profile (0-100 cm) were 4.22, 6.58 and 8.59 cm·min-1/2 in the sandy grassland, fixed sand dune and mobile sand dune, respectively, and decreased gradually with the increase of soil moisture. (3) The lowest, intermediate and highest soil moisture diffusivities for the 0-100 cm soil layer were found in the sandy grassland (1.21 cm2·min-1), fixed sand dune and (4.51 cm2·min-1) and mobile sand dune (12.75 cm2·min-1), respectively. The relationship between soil moisture diffusivity and soil moisture for the three habitats was fitted much better by an empirical equation, D(θ)=ae. There was no consistent trend of D(θ) with increasing in soil depth for all the three habitats. This implied that there was a large difference in D(θ) among different habitats and between different soil depths for the same habitat, and D(θ) had higher spatial heterogeneity in this region. (4) Soil organic matter content and the clay+silt content (<0.05 mm) were the key soil factors negatively affecting D(θ). In addition, habitat type and plant root depth also had some influence on D(θ).

Key words: heterotrophic nutrition, molecular nutrition markers., symbiotic coral