青藏高原东北缘黄土区典型立地人工林分土壤水分特性研究

为探讨青藏高原东北缘黄土区典型立地人工林分的土壤水分特性及耗水特性,本研究以青海云杉林地和祁连圆柏林地作为研究对象,对其土壤持水特性、土壤渗透特性、土壤水分动态和土壤耗水特性进行综合分析。研究结果表明:(1)在相同土壤水吸力作用下,青海云杉林地的持水性比祁连圆柏好,荒草地的持水性比林地差。(2)青海云杉林地的土壤渗透性总体优于祁连圆柏,荒草地的土壤渗透性最差。相同坡向,上坡位的土壤渗透性小于下坡位。(3)青海云杉林地土壤水分条件总体优于祁连圆柏,而荒草地土壤水分条件优于林地;半阴坡林地土壤含水量随坡位由上至下逐渐升高。(4)生长季期间,青海云杉林地平均耗水量大于祁连圆柏,而荒草地耗水量远小于林地。综上,青海云杉林地的土壤水分特性整体优于祁连圆柏林地,且二者的土壤水分状况都比较好,并未出现土壤干层、土壤水分过度消耗等现象,青海云杉和祁连圆柏在研究区的配置是合理的,可以作为当地的水源涵养树种。

Soil moisture characteristics of typical standing artificial forests in loess area of the northeastern Tibetan Plateau

To investigate the characteristics of soil moisture and water consumption of typical standing artificial forests in the loess area of the northeastern margin of the Qinghai-Tibet Plateau, the Picea crassifolia and Juniperus przewalskii Kom. lands were examined in this study. A comprehensive analysis of their soil water-holding characteristics, soil permeability characteristics, soil moisture dynamics, and soil water consumption characteristics was performed. The results showed that:1) under the same soil water suction conditions, the water holding capacity of the P. crassifolia land was better than that of the J. przewalskii Kom. land, and the water holding capacity of the desert grassland was worse than that of the forest land; 2) the soil permeability of the P. crassifolia land was generally better than that of the J. przewalskii Kom. land, and the soil permeability of the desert grassland was the worst. The soil permeability of the upper position was less than that of the lower position on the same slope; 3) the soil moisture condition of the P. crassifolia land was better than that of the J. przewalskii Kom. land, and the soil moisture condition of the desert grassland was better than that of the forest land. The soil water content of the forest on the west-facing slopes gradually increased with a decrease in slope height; 4) during the growing season, the average water consumption of the P. crassifolia land was more than that of the J. przewalskii Kom. land, whereas the water consumption of the desert grassland was much lower than that of the woodland. In summary, the soil moisture characteristics of the P. crassifolia land were better than those of the J. przewalskii Kom. land, and the soil moisture statuses for both of them were good. The phenomena of excessive soil water consumption and dry layer of soil were not observed. The configuration of P. crassifolia and J. przewalskii Kom. in the study area is reasonable and they can be used as tree species for local water conservation.