Scholarlink

<p>Rainwater undergoes hydrological and chemical transformations as it passes through the forest canopy. However, this process in urban forests has received less attention compared to natural ecosystems, leading to an underestimation of their purification. This study investigated precipitation and nutrient redistribution in an urban forest in Guangzhou, southern China, a characteristic subtropical region. Heavy metal concentrations in rainfall, throughfall, and stemflow were meticulously measured in 147 precipitation events and sampled from January 2020 to September 2021. A canopy budget model was employed to estimate the contribution of canopy exchange and dry deposition to the net rainfall (throughfall + stemflow) nutrient flux. The annual input of heavy metals in precipitation was 293.82&#xa0;g ha⁻¹ y⁻¹, which increased to 496.08&#xa0;g ha⁻¹ y⁻¹ after canopy redistribution. Of this increase, 117.73&#xa0;g ha⁻¹ y⁻¹ originated from dry deposition and 84.54&#xa0;g ha⁻¹ y⁻¹ from the canopy exchange process. Except for Manganese (Mn), which was absorbed by the canopy, all other elements Chromium (Cr), Copper (Cu), Arsenic (As), Caesium (Cs), Plumbum (Pb) leached from the canopy. Giving that impervious surfaces are persistent sources of metal resuspension, and depositions are efficiently recycled into respirable particles, these findings suggest that forest canopies can purify heavy metals from atmospheric deposition at a 1:2.5 area efficiency ratio relative to urban surfaces. These results not only enhance our understanding of heavy metal circulation within the canopy but also offer further insights for mitigating urban heavy metal pollution.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Canopy Exchange Process of Heavy Metals in Subtropical Urban Forest in Southern China

  • 期刊论文

  • 发表日期：

    2025年9月3日

查看全文
  • Han-Wen Zhang,
  • Zhi-Yun Jiang,
  • Yi-Hua Xiao,
  • Lin Huang,
  • Shui-Xia Li,
  • Zhi-Gao Fu,
  • Si-Yi Zhang,
  • Yu-Jun Ma

摘要

Rainwater undergoes hydrological and chemical transformations as it passes through the forest canopy. However, this process in urban forests has received less attention compared to natural ecosystems, leading to an underestimation of their purification. This study investigated precipitation and nutrient redistribution in an urban forest in Guangzhou, southern China, a characteristic subtropical region. Heavy metal concentrations in rainfall, throughfall, and stemflow were meticulously measured in 147 precipitation events and sampled from January 2020 to September 2021. A canopy budget model was employed to estimate the contribution of canopy exchange and dry deposition to the net rainfall (throughfall + stemflow) nutrient flux. The annual input of heavy metals in precipitation was 293.82 g ha⁻¹ y⁻¹, which increased to 496.08 g ha⁻¹ y⁻¹ after canopy redistribution. Of this increase, 117.73 g ha⁻¹ y⁻¹ originated from dry deposition and 84.54 g ha⁻¹ y⁻¹ from the canopy exchange process. Except for Manganese (Mn), which was absorbed by the canopy, all other elements Chromium (Cr), Copper (Cu), Arsenic (As), Caesium (Cs), Plumbum (Pb) leached from the canopy. Giving that impervious surfaces are persistent sources of metal resuspension, and depositions are efficiently recycled into respirable particles, these findings suggest that forest canopies can purify heavy metals from atmospheric deposition at a 1:2.5 area efficiency ratio relative to urban surfaces. These results not only enhance our understanding of heavy metal circulation within the canopy but also offer further insights for mitigating urban heavy metal pollution.