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生态学杂志 ›› 2025, Vol. 44 ›› Issue (5): 1551-1560.doi: 10.13292/j.1000-4890.202505.032

• 研究报告 • 上一篇    下一篇

上海市不同城市化水平区域森林土壤中汞形态特征

李然1,王艳林2,王永杰3,邓泓1,4,5*
  

  1. 1华东师范大学生态与环境科学学院, 上海 200241; 2杭州市临平区启文中学, 杭州 311199; 3华东师范大学地理科学学院, 上海 200241; 4华东师范大学上海市城市化生态过程与生态恢复重点实验室, 上海 200241; 5崇明生态研究院, 上海 202162)

  • 出版日期:2025-06-10 发布日期:2025-05-13

Characteristics of mercury fraction of forest soil along an urbanization gradient in Shanghai.

LI Ran1, WANG Yanlin2, WANG Yongjie3, DENG Hong1,4,5*   

  1. (1College of Ecology and Environmental Science, East China Normal University, Shanghai 200241, China; 2Qiwen Middle School, Linping District, Hangzhou 311199, China; 3School of Geographical Sciences, East China Normal University, Shanghai 200241, China; 4Shanghai Key Laboratory of Urbanization Ecological Processes and Ecological Restoration, East China Normal University, Shanghai 200241, China; 5Institute of Eco-Chongming, Shanghai 202162, China).

  • Online:2025-06-10 Published:2025-05-13

摘要: 城市化过程及植物群落对汞在土壤中的迁移转化具有重要意义。通过野外采样,分析了上海市不同城市化水平区域(即远郊区、近郊区和中心城区)香樟(Cinnamomum camphora)林、水杉(Metasequoia glyptostroboides)林和常绿落叶混交林土壤中总汞(THg)、甲基汞(MeHg)和总有机碳(TOC)浓度,并利用热解析方法研究土壤汞的形态。结果表明:(1)城市森林表层土壤(0~2 cm)THg浓度变化范围为34.01~317.98 ng·g-1,表现出中心城区>近郊区>远郊区的空间分布模式,即城市化梯度是影响土壤汞浓度的重要因素。综合全年的数据,表层土壤MeHg主要受THg浓度的影响(R2=0.323, P<0.01),但与TOC浓度没有显著关系(P>0.05)。(2)在0~20 cm的垂直剖面上,土壤MeHg浓度与THg和TOC浓度均显著正相关(RTHg=0.231,R2TOC=0.588, P<0.01)。不同形态的汞影响甲基汞的生成,吸附态汞和有机结合态汞是影响剖面土壤汞甲基化的重要因素。(3)与香樟林相比,水杉林和混交林土壤MeHg含量较高,说明落叶树木林下土壤更易甲基化。


关键词: 城市化, 城市森林土壤, 总汞, 甲基汞, 不同热稳定性汞

Abstract:

Urbanization and plant community play important roles in mercury migration and transformation in soils. To investigate the characteristics of mercury along an urbanization gradient, we analyzed the total mercury (THg), methylmercury (MeHg), and total organic carbon (TOC) concentrations in the soil of three forests, i.e. Cinnamomum camphora forest, Metasequoia glyptostroboides forest and evergreen-deciduous mixed forest, from the outer suburb, inner suburb and central urban district of Shanghai. The speciation of soil mercury was analyzed by thermal analysis method. The results showed that: (1) the THg concentration in the surface soil (0-2 cm) of urban forests varied from 34.01 to 317.98 ng·g-1, with an obvious spatial pattern of central urban district > inner suburb > outer suburb, indicating that soil mercury was affected by urbanization. Based on the annual data, MeHg concentration of surface soil was correlated with THg concentration (R2=0.323, P<0.01) instead of soil TOC concentration (P>0.05). (2) Across the 0-20 cm soil profile, soil MeHg concentration was significantly positively correlated with both THg and TOC concentrations (R2THg=0.231, R2TOC=0.588, P<0.01). Hg forms affected the formation of mercury methylization. The speciations of adsorbed and organically bound mercury were important factors influencing the methylation of mercury in soil. (3) Compared to Cinnamomum camphora forest, soil MeHg concentration was higher in Metasequoia glyptostroboides forest and mixed forest, indicating that soils under deciduous trees were more methylated.

Key words: urbanization, urban forest soil, total mercury, methylmercury, mercury with different thermal stability