陕北黄土区人工刺槐林地土壤水势特征

发布时间：2018-04-17 05:22

  本文选题：黄土区 + 刺槐林地　； 参考：《水土保持学报》2017年03期

【摘要】：为了研究黄土区人工林地土壤水分特征曲线及土壤水势特征,以陕北黄土区人工刺槐林地为研究对象,利用中子水分仪和中国科学院地理科学与资源研究所设计的负压计,对其2015年4月1日—2015年10月31日0—200cm土层的土壤含水量和土壤水势进行了连续观测,并运用灰关联法分析了表层(0—40cm)、中层(50—120cm)、深层(130—200cm)及4—10月土壤水势灰关联度。结果表明:(1)陕北黄土区人工刺槐林地各土层土壤水分特征曲线可用Gardner模型幂函数方程θ=aS-b进行拟合,拟合参数a值大小为表层土壤(0.103 8)中层土壤(0.094 4)深层土壤(0.086 0);b值大小为表层土壤(0.284)中层土壤(0.291)深层土壤(0.298)。(2)通过土壤水分特征曲线求得人工刺槐林地土壤水分常数,田间持水量和凋萎系数的平均值分别为25.53%和8.42%,最大有效水范围平均达17.11%。通常用土壤水吸力为0.1 MPa时,比水容量值来表征土壤供水能力,人工刺槐林地该值的大小表现为表层土壤(56.73%)中层土壤(53.74%)深层土壤(50.84%)。(3)人工刺槐林地土壤水势垂直空间分布表现为表层土壤水势从-0.21 MPa逐层增加到-0.08 MPa,中层土壤水势动态波动较大,整体呈下降趋势,深层土壤水势稳定在-1.14 MPa附近。灰关联度分析得出R12(0.899 8)R23(0.711 5)R13(0.702 8),人工刺槐林地土壤水势表层与中层关系较为密切,深层与中层关系次之,表层与深层关系最差。(4)人工刺槐林地0—200cm土层土壤水势,4—6月呈下降趋势,7—8月显著上升,9—10月再次下降。从各月土壤水势灰关联度来看,R_(10)(0.868 9)R_(05)(0.806 7)R_(09)(0.780 4)R_(07)(0.676 3)R_(06)(0.654 8)R_(08)(0.611 4),人工刺槐林地土壤水势10月,5月,9月变化态势与4月关联度较高;土壤水势7月,6月,8月与4月关联度较差。
[Abstract]:In order to study soil water characteristic curve and soil water potential characteristics of artificial forest land in loess region, the artificial Robinia pseudoacacia forest land in North Shaanxi Province was studied. The negative pressure meter was designed by neutron moisture meter and Institute of Geography and Resources of Chinese Academy of Sciences.The soil moisture content and soil water potential of 0-200cm soil layer from April 1, 2015 to October 31, 2015 were continuously observed.The grey correlation degree of soil water potential between April and October was analyzed by using grey correlation method in surface layer (0-40 cm), middle layer (50-120 cm) and deep layer (130-200 cm).The results showed that the soil moisture characteristic curves of artificial Robinia pseudoacacia forest in North Shaanxi could be fitted by the power function equation 胃 (aS-b) of Gardner model.The fitting parameter a value is surface soil (0.1038)) middle soil (0.094 4)) deep layer soil (0. 2884) middle soil (0. 291)) deep layer soil (0. 298N. 2) soil moisture constant of artificial Robinia pseudoacacia forest is obtained by soil water characteristic curve.The average values of field water holding capacity and wilting coefficient were 25.53% and 8.42%, respectively, and the maximum effective water range was 17.11%.When the soil water suction is 0. 1 MPa, the specific water capacity is used to characterize the soil water supply capacity.The value of soil water potential in artificial Robinia pseudoacacia forest was 56.73) (53.74)) the vertical spatial distribution of soil water potential of artificial Robinia pseudoacacia forest showed that the surface soil water potential increased from -0.21 MPa to -0.08 MPa, and the dynamic fluctuation of soil water potential in middle layer was larger than that in artificial Robinia pseudoacacia forest, and the soil water potential of artificial Robinia pseudoacacia forest was increased from -0.21 MPa to -0.08 MPa.The water potential of deep soil was stable at -1.14 MPa.Grey correlation analysis showed that R12C 0.899 8)R23(0.711 5)R13(0.702 8, soil water potential in artificial Robinia pseudoacacia forest had a close relationship with the middle layer, followed by deep layer and middle layer.Soil water potential of 0-200cm soil layer in artificial Robinia pseudoacacia forest showed a downward trend in April-June and increased significantly in July-August and decreased again in September-October.According to the grey correlation degree of soil water potential in each month, 0.868 9)R_(05)(0.806 7)R_(09)(0.780 4)R_(07)(0.676 3)R_(06)(0.654 8)R_(08)(0.611 4C was observed. The variation of soil water potential in October, May and September in artificial Robinia pseudoacacia forest was higher than that in April, and the correlation degree of soil water potential in July, June, August and April was poor.
【作者单位】： 北京林业大学水土保持学院;
【基金】：国家林业局公益性行业科研专项经费项目“南方退耕还林工程建设效益监测评价研究”(201004018)
【分类号】：S714
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本文编号：1762266