艾比湖湿地不同植物群落下土壤全磷空间变异

Spatial Variability of Soil Total Phosphorus in Different Plant Communities of Ebinur Lake Wetland

土壤磷素是植物生长所需的必要元素,研究土壤全磷的含量水平及空间分异规律可为湿地土壤肥力水平的评价和生态修复提供科学的理论基础。以艾比湖湿地为研究对象,于2015年8月在环湖一周160km范围内系统采集土壤样品296个,采用地统计学方法分析了不同植物群落土壤全磷的空间变异特征。结果表明:(1)研究区土壤全磷含量变化范围为0.46~1.64g/kg,土壤全磷含量为梭梭群落>梭梭柽柳群落>芦苇群落>胡杨群落,不同区域存在极显著性差异;除梭梭—柽柳,胡杨群落外,其他群落土壤全磷垂直方向上表现为从表层向下递减的趋势,且各层土壤全磷含量差异性显著;(2)梭梭和梭梭—柽柳群落土壤全磷拟合模型均为高斯模型,胡杨和芦苇群落为球状模型,其空间分布相关性很强且空间变异性主要是由成土母质、地形、气候等结构性因素引起;(3)芦苇群落土壤全磷随土壤含水量增加呈降低变化,其他区域均呈增加的趋势;梭梭—柽柳群落土壤全磷与土壤pH值呈线性降低趋势,其他植物群落与土壤pH值呈线性增加的趋势。总体而言,艾比湖湿地土壤全磷具有明显的空间分布差异,与植被差异、pH值和土壤水分密切相关。

Soil phosphorus is the necessary element for plant growth.Understanding the content and spatial distribution of total phosphorus in soil can provide a scientific basis for the evaluation of soil fertility and ecological restoration of wetland ecosystem.The wetland in Lake Ebinur was selected as the study area.In August 2015,296 soil samples were collected in circle of Lake about 160 km.Soil total phosphorus contents were examined by geostatistical analysis method in order to reveal the spatial distributions of different plant communities.Results showed that soil total phosphorus contents ranged from 0.46 to 1.64g/kg and decreased in the order:Haloxyloncommunities>Haloxylon-Tamarixcommunities>Phragmites communities>Euphraticacommunities,soil total phosphorus contents were significantly different in different communities.With the exception of Euphratica and Haloxylon-Tamarix communities,contents of soil total phosphorus generally decreased with increase of depth in other communities.Significant differences were observed for soil total phosphorus contents in different soil layers.The optimal fitting model of total phosphorus is Gaussian in Haloxyloncommunity and Haloxylon-Tamarix community while spherical model can describe the distribution of soil total phosphorus in Euphratica community and Phragmites community,the spatial variation of total phosphorus is strong and influenced by structural factors such as parent material,terrain and climate.The correlation between total phosphorus and soil moisture in Phragmites community was negative while the correlations were positive in the others.The correlation between total phosphorus and pH val-ue in Haloxylon-Tamarixcommunity was negative while the correlations were positive in the others.Overall,the total phosphorus content in Ebinur Lake wetland presents obvious spatial distribution,which is closely related to vegetation patterns,pH value and soil moisture.