[Effects of Wetland Types on Distribution of Soil Methylmercury Based on the Region of Nanweng River in the Greater Xing'an Mountains]

Xin-Quan Zhou; Yu-Rong Liu; Jing Li; Zhi-Feng Zhou

doi:10.13227/j.hjkx.201805204

[Effects of Wetland Types on Distribution of Soil Methylmercury Based on the Region of Nanweng River in the Greater Xing'an Mountains]

Huan Jing Ke Xue. 2018 Dec 8;39(12):5480-5486. doi: 10.13227/j.hjkx.201805204.

[Article in Chinese]

Authors

Xin-Quan Zhou^{1

2}, Yu-Rong Liu², Jing Li³, Zhi-Feng Zhou¹

Affiliations

¹ College of Resources and Environment, Southwest University, Chongqing 400715, China.
² Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
³ Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China.

PMID: 30628391
DOI: 10.13227/j.hjkx.201805204

Abstract

Methylmercury (MeHg) is the most toxic organic matter of all mercury (Hg) compounds. Its toxicity is far higher than that of inorganic Hg. Methylmercury can enter the human body through food, threatening human health. Based on the Nanweng River National Nature Reserve in the Greater Xing'an Mountains, the differences in the distribution of MeHg in soil samples collected from four types of wetlands, including medium swamp, low swamp, island forest, and forest soil, and the effect of the soil properties on the MeHg content were investigated in this study. The results show that:① the trends of the total Hg and MeHg levels are inconsistent. The order of the mean total Hg content is island forest (138.76 mg·kg^-1±101.97 mg·kg^-1) > forest soil (117.57 mg·kg^-1±32.44 mg·kg^-1) > low swamp (71.8 mg·kg^-1±1.42 mg·kg^-1) > median swamp (65.11 mg·kg^-1±26.69 mg·kg^-1), while the mean MeHg content is in the order of island forest (1.14 μg·kg^-1±1.15 μg·kg^-1) > medium swamp (0.87 μg·kg^-1±1.06 μg·kg^-1) > low swamp (0.28 μg·kg^-1±0.06 μg·kg^-1) > forest soil (0.1 μg·kg^-1±0.05 μg·kg^-1); ② the contents of MeHg in the island forest and medium swamp were relatively high and fluctuated dramatically, whereas the contents of MeHg in the low swamp and forest soil were lower and showed little change between each sampling point; ③ the longer the marsh wetland formation was, the higher was the MeHg content, that is, median swamp (0.87 μg·kg^-1±1.06 μg·kg^-1) > low swamp (0.28 μg·kg^-1±0.06 μg·kg^-1); the soil pH was positively correlated with MeHg (P<0.05); in the medium swamp area, the content of MeHg was positively related to the water content (WC), organic matter (OM%), carbon (C%), and total mercury (THg; P<0.05); in the island forest areas, the MeHg content showed a linear relationship with the soil pH and NH₄⁺-N (P<0.05). This study reveals the distribution characteristics of MeHg and its influencing factors for different wetland ecosystems, providing data supporting the comprehensive evaluation of MeHg accumulation in wetland ecosystems.

Keywords: Nanweng River; methylmercury; soil properties; total mercury; wetland.

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English Abstract