苔藓结皮层土壤矿质元素含量变化特征

Variety characteristics of total soil minerals in mossy biological crusts

土壤中全量化学元素既是植物矿质营养的源泉,又是全面影响土壤肥力高低的一个重要因素,其含量多少对分析土壤形成演化过程具有指导意义。文中采用电感耦合等离子体发射光谱仪(PE ICP-OES)分析测定了沙地沙漠固沙林植被下苔藓结皮层全量化学元素含量变化。结果表明,苔藓结皮层SiO2平均含量为60.77%,其它全量化学元素组成(SiO2除外)含量均高于流动沙土;随着固沙林时间的增加以及苔藓结皮不断积累更多的细颗粒物质,苔藓结皮层SiO2含量呈现出明显降低的趋势,而其它全量化学元素含量均呈现增加趋势。苔藓结皮层硅铁铝率低于对照流动沙土,且随着固沙林时间的增加,硅铁铝率均呈现降低趋势,同时大气降尘中的全量化学元素组成含量以及硅铁铝率均高于苔藓结皮层和流动沙土。风沙环境下苔藓结皮层的形成和长期保留,对改善风沙土矿物质元素含量具有积极作用。

The full amount of chemical elements in the soil is not only the source of the plant’s mineral nutrition,but also an important factor affecting the soil fertility level,and its content is of guiding significance for the analysis of soil formation and evolution.In this paper,the inductively coupled plasma optical emission spectrometer(PE ICP-OES)was used to analyze the changes of total chemical elements in the biological crust of sandy desert moss.The results showed that the average content of SiO2 in the mossy biological crust was as high as 60.77%,and the total chemical composition(excluding SiO2)was higher than that in the mobile sand.With increasing sand-fixing plantation age and moss crusts continuing to accumulate more fine particulate matter,the content of SiO2 showed a significant decrease trend,and the content of other total chemical elements showed an increasing trend.The rate of ferrosilicon-aluminum in moss crusts was lower than that in control sand soils,and with increasing of sand-fixing age,the rate of ferrosilicon-aluminum showed a decreasing trend.At the same time,the total chemical element content and the rate of ferrosilicon-aluminum in atmospheric dust were more than that in the mossy crust layer and the control flowing sand.The formation and long-term retention of bryophyte crusts under wind and sand conditions had a positive effect on improving the content of mineral elements in sand soil.