飞播马尾松林土壤水分垂直变化特征及其影响因素

Vertical Variation Characteristics of Soil Moisture and Its Influencing Factors of Aerially Seeded Pinus massoniana Plantation

以赣南飞播马尾松林为研究对象,将林地土层按土壤深度(d)进行土层划定,其中0<d≤10 cm为Ⅰ土层、10 cm<d≤20 cm为Ⅱ土层、20 cm<d≤40 cm为Ⅲ土层、40 cm<d≤80 cm为Ⅳ土层,采用统计分析、冗余分析等方法探讨林地不同土层土壤水分的变化特征及其与植被、地形、土壤等因素间的定量关系。结果表明:随着土壤深度的增加,土壤含水量、田间持水量均增大,其中Ⅳ土层的土壤含水量显著高于Ⅰ、Ⅱ土层(P<0.05),Ⅲ土层的土壤含水量显著高于Ⅰ土层(P<0.05);Ⅳ土层的田间持水量显著高于Ⅰ土层(P<0.05)。土壤水分主要受土壤密度、毛管孔隙度等土壤因子的影响,其次受草本盖度、枯落物厚度、地被盖度等植被因子的影响,受地形因子的影响最小。在各土层中,均以土壤因子的独立作用为主,次要因子为植被因子的独立作用及其与其他因子的交互作用。其中,植被、地形因子主要是通过影响土壤因子作用于土壤水分。

From studying the forest and measurement of the soil moisture in the laboratory,the changing characteristics of soil moisture in different soil layers(0-10,10-20,20-40,and 40-80 cm)were analyzed,and the quantitative relationship among soil moisture,vegetation,topography and soil was discussed by redundancy analysis.With the increasing of soil depth,both the soil water content and the field water capacity were increased.The soil water content in the layer of 40-80 cm was significantly greater than that in the layer of 0-10 and 10-20 cm(P<0.05).The soil water content in the layer of 20-40 cm was significantly greater than that in the layer of 0-10 cm(P<0.05).The field water capacity in the soil layer of 40-80 cm was significantly higher than that in the layer of 0-10 cm(P<0.05).The soil moisture was mainly affected by soil factors such as soil bulk density and capillary porosity,followed by vegetation factors such as herb coverage,litter thickness and ground cover etc.The topographic factors had the least influence.In each soil layer,the soil factor was the independently dominant factor,and the secondary factor was the independent vegetation factor and its interaction with other factors.Vegetation and topographic factors changed soil moisture mainly through influencing soil factors.