地下水位埋深对沙质草地典型植物群落土壤环境因子和根系生物量的影响  

Effects of groundwater depth on soil environmental factors and root biomass of typical plant communities in sandy grassland

作　　者：苏天燕 贾碧莹 胡云龙 杨秋[1] 毛伟 SU Tianyan;JIA Biying;HU Yunlong;YANG Qiu;MAO Wei(College of Ecology and Environment,Hainan University,Haikou 570228,Hainan,China)

机构地区：[1]海南大学生态与环境学院,海南海口570228

出　　处：《草业科学》2021年第9期1694-1705,共12页Pratacultural Science

基　　金：国家自然科学基金(41671208);海南大学科研启动基金项目(KYQD20035)。

摘　　要：干旱半干旱地区水分蒸发剧烈且植被生长依赖于地下水分补给,因此植被地下部分的生长受限于地下水位埋深的高低。为探明植被地下部分(根系生物量)与生长环境因子(土壤养分和pH)及其相互关系受地下水位埋深的影响,在科尔沁沙质草地进行了地下水位埋深梯度倍数递增(0.5、1.0和2.0 m)控制试验。结果表明:1)在不同地下水位埋深控制试验中土壤全氮、全磷和pH均随年际变化而上升,且各处理间存在显著差异(P<0.05);而土壤有机碳含量则呈下降趋势,且各处理间无显著差异(P>0.05)。土壤有机碳、全氮和全磷含量总体上均随地下水位埋深土层深度的加深而降低,而pH随着土层深度的加深而上升,但变化差异不显著。2)根系生物量在不同地下水位埋深深度中均随土层深度的加深而下降。3)土壤有机碳、全氮和全磷与根系生物量显著正相关,pH与根系生物量负相关,但不显著。因此,本研究证明不同地下水位埋深梯度处理对不同的土壤养分类型影响不一,但科尔沁沙质草地地下水位埋深会加快土壤有机碳、全氮和全磷含量的丧失和根系生物量的增加。Evaporation is severe in arid and semi-arid areas,and vegetation growth in these areas depends on the groundwater supply.The growth of the underground part of vegetation is limited by the depth of the groundwater table.To determine if the underground part of vegetation(root biomass),growth environmental factors(soil nutrients and pH),and their relationship are affected by the groundwater table depth,a controlled experiment with an increasing groundwater table depth(0.5,1.0,and 2.0 m)was conducted in Horqin sandy grassland.The results were as follows:1)soil total nitrogen,total phosphorus,and pH increased as the groundwater table depth changed in the control tests,and there were significant differences among the treatments(P<0.05).However,the soil organic carbon content showed a downward trend,and there was no significant difference among the treatments.The soil organic carbon,total nitrogen,and total phosphorus contents all decreased as the groundwater table depth increased,whereas the pH increased as the soil depth increased,but the difference was not significant.2)The root biomass decreased as the soil depth increased at different groundwater depths.3)Soil organic carbon,total nitrogen,and total phosphorus were positively correlated with the root biomass,whereas the pH was not negatively correlated with the root biomass.Therefore,this study shows that different groundwater table depth treatments have different effects on different soil nutrient types,but the groundwater table depth in Horqin sandy grassland will accelerate the loss of soil organic carbon,total nitrogen,and total phosphorus contents and the increase in root biomass.

关 键 词：沙质草地 环境因子 地下水位 土壤养分 根系生物量 土壤有机碳 白草 

分 类 号：S812.2[农业科学—草业科学]