辽西北风沙区典型利用类型下的土壤水分变化特征

Characteristics of Soil Moisture Changes Under Typical Utilization Types in the Windy and Sandy Areas of Northwest Liaoning

选取科尔沁沙地南缘不同土地利用类型为研究对象,在2022年4—10月对0~150 cm土层土壤含水率进行测量,分析樟子松人工林、灌木林地、草地、农田、半固定沙地5种方式下土壤垂直剖面含水率分布特征、土壤储水量变化特征、土壤蒸散发变化特征。结果表明:灌木林和草地的土壤含水率分布呈“W”形;樟子松人工林、半固定沙地的含水率分布呈“U”形;农田含水率分布呈倒“U”形,且含水率最小值位置与该土地利用类型植被根系分布情况有关。不同土地利用类型土壤储水量具有明显的季节性变化特征,且于降雨量变化基本一致。5种土地利用类型土壤水分皆为盈余状态,其中草地的保墒效果最好。因此,该地区的生态植被应优先考虑修复草本或疏林草地,以利于维护土壤水环境及其可持续利用。

Taking different land use types in the southern edge of Horqin Sandy Land as the research object,the soil moisture content of 0-150 cm soil layer was measured from April to October 2022,and the soil moisture content of 0-150 cm soil layer was measured from April to October 2022,and the distribution characteristics of soil vertical profile moisture content,soil water storage change characteristics and soil evapotranspiration change characteristics under five patterns of the vertical profile distribution characteristics,soil water storage change characteristics,and soil evapotranspiration change characteristics of soil moisture under five patterns of Pinus sylvestris var.mongolica forest land,shrubbery,grassland,farmland and semi fixed sandy land were analyzed.The results showed that the distribution of soil moisture content in shrublands and grasslands was in a“W”shape;the water content distribution of Pinus sylvestris plantation and semi fixed sandy land was“U”shape;the distribution of water content in farmland showed an inverted“U”shape,and the position of the minimum water content was related to the distribution of vegetation roots in the land use type.The soil water storage capacity of different land use types had obvious seasonal variation characteristics,and the changes in rainfall were basically consistent.All 5 types of land use had surplus soil moisture,among which grassland had the best entropy retention effect.Therefore,priority should be given to herbaceous plants for ecological vegetation restoration in the region,in order to facilitate the soil water environment and its sustainable utilization.