北方农牧交错带不同退耕方式下土壤水分变化特征

研究退耕还林、退耕还灌、退耕还草不同退耕方式对土壤水环境的影响.结果表明:北方农牧交错带植被耗水主要靠降水满足;3种不同退耕方式的植被生育期内土壤水分含量均随降水量而变化;土壤表层(0～30 cm)水分含量相差不大;在30～100 cm土层,林地土壤水分含量始终高于灌木地和草地,草地的最低;对于0～100 cm土层,林地相对于灌木地和草地能更好地维持土壤水分;2005年3种退耕方式的植被在生长季中对水分的消耗均超过降水补给.

Characteristics of soil water changes under different ways of returning farmland to forest and grassland in the ecotone between agriculture and animal husbandry areas in North China

In the semi-arid areas of the ecotone between the agriculture and animal husbandry areas in north China,soil water is crucial to agricultural production.In order to evaluate the effect on soil moisture of different methods of restoring farmland to forest and grassland,this paper analyzed the temporal and spatial variations of soil moisture under forestland,shrub land,and grassland.The soil moisture within 0-100 cm was measured during the growing period in 2005.The results indicated:1)Water consumption of different types of vegetation during the growing season was mainly dependent on the rainfall.In general,the changes of soil moisture content corresponded to the amount of precipitation during the growing season.2)There was little difference in the soil water content in the 0-30 cm range among the various types of vegetation.In the 30-100 cm soil layer,the soil water content in forestland was higher than that in shrub land and grassland,and the soil water content in shrub land was higher than that in grassland during the growing season in 2005.In the 0-100 cm soil layer,the maintenance of soil water content in the forested area was better than that of the shrub land and grassland.3)The water consumption of the three different types of vegetation during the growing season was higher than the amount of precipitation received in 2005.