典型草原自然演替过程中土壤理化性质动态变化

以内蒙古巴林右旗退化典型草原为研究对象,采用空间序列代替时间序列的方法,探讨围封条件下,退化典型草原自然恢复过程中土壤物理性质及养分的动态变化。结果表明:围封对典型草原土壤含水量产生深刻影响,土壤水分含量呈增加趋势,增加最明显的是土壤表层0~5 cm;典型草原群落自然恢复过程中,土壤有机质、全氮、速效氮、速效钾增加极显著(P<0.01),全磷和速效磷增加较为显著(0.01<P<0.05),同时,土壤养分有明显的表聚现象;典型草原群落去除放牧践踏的干扰后,土壤物理性状得以改善,恢复6年和10年的0~5 cm土层土壤容重分别为1.27和1.25 g/cm3,显著低于恢复初期的土壤容重(P<0.05)。

Dynamics of Soil Physicochemical Properties during the Natural Restoration and Succession of Typical Steppe in Inner Mongolia Autonomous Region

A field experiment was conducted in a degraded area of typical steppe ecotype in Balinyou Banner,Inner Mongolia Autonomous Region,China to reveal the dynamics of soil physicochemical properties,using a space series method in stead of time course method,during natural restoration and succession after having been removed human activities by fencing.The results show that enclosure greatly affected the soil water content with an increasing trend,especially in surface soil layer 0~5 cm.During the self-organization restoration of typical steppe community,organic matter,total N,available N,and available K increased significantly(P<0.01),total P and available P increased obviously(0.01<P<0.05),and soil nutrient mostly distributed in surface soil layer.Soil physical characters were gradually improved after the elimination of grazing and trampling in typical steppe.Soil bulk density was 1.27 g·cm^-3 and 1.25 g·cm^-3 after 6 year and 10 year restoration,respectively,and was significantly lower in comparison with the early restoration stage(P<0.05).