Evaluation of Heavy Metal Level in Soil of Typical Alpine Grassland Communities

Huilan Shi,Yukun Wu,Jianjun Shi,Jiancai Sun,Jiexue Zhang,Zhiyong Liu,Deting Deng,Zhonghua Duan,Sha Yang,S.O Oladokun,S Lu

doi:10.1051/e3sconf/202021804025

Abstract

Objective: Through the investigation, determination and analysis of heavy metals in the soil of typical alpine grassland community, five kinds of alpine grasslands with different degeneration degree of Maduo County in Alpine area, two kinds of alpine grassland with high Maqu County, high Alpine desert along the coast of Qinghai Lake, alpine thickets in the yellow South region, Alpine wetlands, The condition of soil heavy metals in alpine meadow and other communities is analyzed, which provides scientific guidance for the ecological protection measures of typical alpine grassland communities, and provides a basis for the sustainable utilization of Alpine grassland. Methods: The content of various kinds of heavy metals in soil samples was determined by ICP-MS, and the pollution status of heavy metals was analyzed by means of single factor pollution index method, Nemero comprehensive pollution index method and potential ecological risk index method by using Excel. Results: (1) The content of Cd in Maduo, Maqu, Qinghai Lake and Huangnan was 1.74, 0.97, 1.84 and 1.06 times times the soil environment background respectively, and the content of Hg in Maqu was 1.36 times times that of soil environmental background value. The variation coefficient of Hg and Pb in Maqu and the coefficient of variation of Cd in Qinghai Lake are more than 100%, which is in the degree of high variation, which is greatly influenced by man. (2) The highest total pollution index in the 4 sample places was in the area of MA diversity, at 1.33. The second is the Huangnan sample, with an exponential value of 0.86. The Nemero comprehensive pollution Index of the Maqu sample is 0.77. The index value of Qinghai Lake sample is the lowest, at 0.61. (3) The highest potential ecological hazard index is the most diverse, in 0-10, 10-20, 20-30cm three soil layers are 96.96, 103.58, 102.46, Maqu in 0-10, 10-20cm soil, the potential ecological hazard index is 65.70, 71.01, the potential ecological hazard index of Huangnan in three soil layer is 78.23, 73.42 and 72.84 respectively, which refers to the smallest value of Qinghai Lake sample, three, 51.07 and 51.72 in 51.48 soil layer respectively. Conclusion: The Nemero comprehensive pollution Index of Qinghai Lake sample is less than 0.7, at the level of cleanliness, the exponential value of Huangnan and Maqu two samples is between 0.7~1, at the level of cordon, and the exponential value of ma variety is between 1~2, at the level of mild pollution. The comprehensive potential ecological hazard index of 80~160 has the potential ecological risk of strength, and the exponential value of the other three samples is between 40~80, which has medium potential ecological risk. Generally, the pollution degree of heavy metals is small in the whole alpine grassland area.

Highlights

The heavy metals are environmental pollutants and potential toxic pollutants, which are featured by long-lasting harm, difficult degradation, amplification effect of food chain enrichment, etc. [1]
Huangnan Tibetan Autonomous Prefecture is located at the southeast of Qinghai Province, and it belongs to plateau continental climate, where Potentilla fruticosa shrub, Elymus nutans grassland, Kobrbresia pygmaea meadow, and Kobresia tibetica marsh meadow were chosen as the study objects
The content of heavy metal Cd exceeded the soil environmental background value in Qinghai Lake sample plot and Huangnan sample plot, and it was Hg content that exceeded the background value in Maqu, which was consistent with the research conducted by Li R Q et al on the soil heavy metal pollution in plateau of Gansu Province, and the Hg content was higher than other heavy metals

Summary

Introduction

The heavy metals are environmental pollutants and potential toxic pollutants, which are featured by long-lasting harm, difficult degradation, amplification effect of food chain enrichment, etc. [1]. The heavy metals are environmental pollutants and potential toxic pollutants, which are featured by long-lasting harm, difficult degradation, amplification effect of food chain enrichment, etc. With the serious environmental disruption in the industrialization development, the sources of heavy metals in the contaminated soil have become the important research direction. The soil heavy metals may vary a lot with the soil formation process, and the atmospheric deposition, sewage irrigation, etc. Are important sources of soil heavy metals [2]. Starting from the sedimentology, Hakanson [3] proposed a method of evaluating and analyzing the heavy metal pollution and ecological risks in soil and sediments in 1980. Pastor J [4] believed that the heavy metal pollutions obviously impacted the species diversity of plant communities. Liu Y et al [5]

Methods

Results

Discussion

Conclusion