灌丛化对贺兰山西坡草场土壤异质性的影响

The Effects of Shrub Patches on Soil Heterogeneity in Grasslands on the West Slope of the Helan Mountain

以贺兰山西坡哈拉乌北沟为例,研究了干旱区灌丛化草场的土壤水分、养分空间分布特征。结果表明:灌丛化显著促进了干旱区草场的土壤养分富集,提高了小尺度的土壤异质性。地统计学分析也表明:0~20 cm的土壤水分、总氮、有机质和pH的空间自相关距离均大于灌丛的平均冠幅(30±12.3)cm,但远小于对照草场相应土壤理化性质的空间分布范围,揭示出灌丛化样地土壤理化性质的分布可能伴随着灌丛尺度上的生物作用过程。

The Helan Mountain is located in an inland region with a continental climate;therefore,it is arid and cold in winter,but arid and hot in summer.The prevailing wind direction in winter is NW,the annual temperature ranges from 8.2 ℃ to 8.6 ℃,the annual accumulated temperature ≥10 ℃ is 511.3 ℃,the annual precipitation ranges from 250 mm to 438 mm,but the annual evaporation is as high as 1 600～1 800 mm,and the frost free period lasts from 110 to 130 days.Here,a case study of the spatial distribution of soil moi...