Institute of Forest Ecology, Environment and Nature Conservation, Chinese Academy of Forestry, Beijing, China.
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Environ Monit Assess. 2022 Apr 7;194(5):344. doi: 10.1007/s10661-022-10004-z.
Tree tissues can accumulate heavy metals from the environment. We therefore aimed to evaluate the presence of the metals Pb, Cr, Mn, Cu, and Zn in four street tree species, namely Ailanthus altissima, Broussonetia papyrifera, Pinus tabuliformis, and Rhus typhina, along the highway side of Beijing, China. Sampling from the leaves, trunk bark, and branch annual segment bark of trees was conducted in the summer of 2021, and the concentration of heavy metals was determined. The results revealed the highest average concentration of total heavy metals in the R. typhina leaves (23.724 mg/kg) and barks (14.454 mg/kg). The maximum bio-concentration factor was noted for Zn in the B. papyrifera leaves (0.36) and P. tabuliformis barks (0.21). The maximum comprehensive bio-concentration index was observed for the B. papyrifera leaves (0.225) and P. tabuliformis bark (0.108). The maximum metal accumulation index was measured in the R. typhina leaves (29.682) and bark (12.407). Based on the air-originated metals, P. tabuliformis showed the highest dust collection capacity. In general, B. papyrifera and P. tabuliformis exhibited the highest absorption rate from the soil relative to the other studied species. R. typhina demonstrated the strongest phytoremediation ability for heavy metal pollution in air. In addition, our results proved that the branch annual segment bark of P. tabuliformis is an excellent record carrier that can be used to monitor heavy metal pollution in a specific time duration in an urban area.
树木组织可以从环境中积累重金属。因此，我们旨在评估中国北京高速公路旁四种街道树种（臭椿、构树、油松和火炬树）的叶片、树干树皮和树枝年段树皮中 Pb、Cr、Mn、Cu 和 Zn 等金属的存在情况。2021 年夏季，我们对树木的叶片、树干树皮和树枝年段树皮进行了采样，并测定了重金属的浓度。结果表明，臭椿叶片（23.724mg/kg）和树皮（14.454mg/kg）中总重金属的平均浓度最高。构树叶（0.36）和油松树皮（0.21）中 Zn 的最大生物浓缩系数最高。构树叶（0.225）和油松树皮（0.108）的最大综合生物浓缩指数最高。臭椿叶片（29.682）和树皮（12.407）的金属积累指数最高。根据空气中的金属含量，油松显示出最高的集尘能力。总的来说，构树和油松相对于其他研究物种，从土壤中吸收的重金属的能力最强。火炬树对空气重金属污染具有最强的植物修复能力。此外，我们的结果证明，油松的树枝年段树皮是一种优秀的记录载体，可以用来监测城市特定时间段内的重金属污染。
