摘要
雪松和圆柏是华北地区广泛种植的行道树种。本文在大气环境质量存在明显差异的天津城区、郊区和山区选取了5个采样点,用电感耦合等离子体原子发射光谱法(ICP)测定了雪松和圆柏的枝条、未清洗针叶、清洗针叶及冠下表层土的重金属(Cu、Mn、Zn和Pb)含量,对数据进行了回归和Pearson相关系数分析。结果表明:城区雪松和圆柏的针叶、枝条及冠下表层土中重金属的含量显著高于山区;雪松针叶对重金属的积累能力显著高于圆柏,城区雪松针叶中Mn、Zn的含量分别高达2024、2397 mg·kg^(-1),是山区雪松针叶的297、479倍,而雪松和圆柏枝条对重金属的积累能力差别不显著;城区和郊区雪松及圆柏未清洗针叶的重金属含量显著高于清洗针叶,说明针叶表层附着物中含有较多重金属;植物组织中高浓度的Cu、Mn、Zn和Pb受城乡环境中多重因素的影响,其中大气沉降是影响植物对城乡环境中重金属积累的重要因素。
The concentrations of Cu, Mn, Zn, and Pb in the samples of Cedrus deodara and Sa- bina chinensis widely planted in North China were examined via ICP and the regression and Pear- son coefficients were also analyzed. The topsoil, branches, unwashed and washed needles were sampled in five plots from the urban, suburban, and rural （mountain） sites of Tianjin where the atmospheric conditions are significantly different. The results indicated that the concentrations of heavy metals in branches, needles and topsoil from the urban site were much higher than that from the rural site. Higher accumulation of heavy metals was detected in C. deodara compared with S. chinensis. The highest concentrations of Mn （2024 mg·kg^-1 and Zn （2397 mg·kg^-1） were observed in C. deodara from the urban site, which were 297 and 479 times higher than that from the rural site, respectively. The concentrations of heavy metals in needles of C. deodara were 15 to 30 times higher than that of S. chinensis, but no differences were found in branches. The concentrations of heavy metals in the unwashed needles were higher than that in the washed needles from both the urban and suburban sites, which indicated that the surface of the needles could adsorb many heavy metals. High concentrations of Cu, Zn, and Pb in aerial parts of trees were mostly a consequence of atmospheric deposition, though other factors could affect this accu- mulation in plants.
出处
《生态学杂志》
CAS
CSCD
北大核心
2015年第12期3368-3373,共6页
Chinese Journal of Ecology
基金
国家科技基础性工作专项(2011FY10300)
天津市野生植物调查项目资助
关键词
雪松
圆柏
大气环境
重金属
积累
Cedrus deodara
Sabina chinensis
atmospheric environment
heavy metals
accumulation.
