荒漠-绿洲过渡带固沙植被土壤剖面水分特征

Soil Profile Moisture Characteristics of Sand Fixing Vegetation in Desert-oasis Ecotone

以黑河中游荒漠-绿洲过渡带固沙植被为例,采用烘干法测定沙拐枣、泡泡刺和梭梭0~120 cm土壤剖面的土壤含水量.结果表明:1)雨季前,沙拐枣、泡泡刺和梭梭土壤含水量随深度增加而增大,值变化范围分别为0.83%~2.17%、0.82%~2.60%、0.79%~1.52%.在0~40 cm,沙拐枣和泡泡刺土壤含水量无显著差异,在40~120 cm,土壤含水量为泡泡刺>沙拐枣>梭梭.2)雨季后,沙拐枣、泡泡刺和梭梭土壤含水量呈增大-减小-趋于稳定的变化趋势,值变化范围分别为1.77%~3.19%、1.43%~2.97%、1.42%~3.41%.在0~60 cm,沙拐枣和泡泡刺土壤含水量无显著差异,在60~120 cm,沙拐枣土壤含水量显著大于泡泡刺和梭梭.3)沙拐枣土壤水分不稳定层深约60 cm,梭梭土壤水分不稳定层深约40 cm,泡泡刺土壤水分在0~120 cm土层内变化不稳定.三种植被的抗旱性强弱为梭梭>沙拐枣>泡泡刺.

Taking the sand fixing vegetation in the desert-oasis ecotone in the middle reaches of Heihe River as an example,the soil moisture content of the 0~120 cm soil profiles of Calligonum mongolicum,Nitraria sphaerocarpa and Haloxylon ammodendron were measured by the drying method.The results show that:1)Before the rainy season,the soil moisture content of Calligonum mongolicum,Nitraria sphaerocarpa and Haloxylon ammodendron shows a trend of increase-reducing-stabilizing change,and the value change ranges with in 0.83%~2.17%,0.82%~2.60%,0.79%~1.52%respectively.In the range of 0~40 cm,there was no significant difference in the soil moisture content between Calligonum mongolicum and Nitraria sphaerocarpa,while in the range of 40~120 cm,the soil moisture content was Nitraria sphaerocarpa>Calligonum mongolicum>Haloxylon ammodendron.2)After the rainy season,the soil moisture content of Calligonum mongolicum,Nitraria sphaerocarpa and Haloxylon ammodendron increased,decreased and tended to be stable,and the range of soil moisture content was 1.77%~3.19%,1.43%~2.97%and 1.42%~3.41%respectively.In the range of 0~60 cm,there was no significant difference in soil moisture content between Calligonum mongolicum and Nitraria sphaerocarpa,while in 60~120 cm,the soil moisture content of Calligonum mongolicum was significantly higher than that of Nitraria sphaerocarpa and Haloxylon ammodendron.3)The unstable soil moisture layer of Calligonum mongolicum was about 60 cm deep,and the unstable soil moisture layer of Haloxylon ammodendron was about 40 cm deep,the soil moisture of Nitraria sphaerocarpa was unstable in 0~120 cm soil layer.The drought resistance of these three kind of vegetation was Haloxylon ammodendron>Calligonum mongolicum>Nitraria sphaerocarpa.