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为了探究城市森林不同树种对大气中重金属的富集能力和分析大气环境质量状况,本文以昆明市东三环边坡的城市森林为试验区,玉溪市磨盘山国家森林公园为对照区,选取两地区分布最广泛的蓝桉、云南松、华山松、圆柏为实验对象,通过测定植物叶片中的重金属含量,对其季节变化规律及重金属元素含量间的相关性进行了分析,结果表明:(1)植物叶片中重金属Zn、Cu、Pb、Cd含量(由春到冬)呈先下降后持续上升的变化趋势;Zn含量春季处于最高值(120.63 mg·kg-1);其余3种重金属元素含量冬季达到最高值.(2)叶片中Cu和Pb含量相关性极显著、金属元素的总含量和Zn、Cd的含量也极显著相关,其相关系数均达到0.85以上;Zn和Pb含量的相关性不显著.大气中重金属Pb污染严重的地区可选择华山松作为城市主要绿化树种、Zn污染严重的地区可选择蓝桉、Cu污染严重的地区可选择圆柏、Cd污染严重的地区4种植物均可选择;试验区的空气污染等级达到了Ⅱ级污染,属于轻度污染区,其中春季大气的综合污染指数最高.

The study was conducted with the objective to explore the atmospheric heavy metal enrichment capability of different urban tree species and analyze atmosphere circumstance.The study made in an urban forest that located in the east third ring road in Kunming whereas the Mopan mountain national forest Park in Yuxi was considered as the control area.The leaves of typical forest species of Eucalyptus globulus,Yunnan pine,Pinus armandi and Sabina chinensis were sampled and the content of heavy metal including Zn,Cu,Pb and Cd were tested.And finally,the seasonal changes and correlation of different kinds of heavy metal elements were analyzed.The results showed that:(1) Heavy metals content of Zn,Cu,Pb,Cd in plant leaves decreased firstly and then increased steadily from spring to winter.The Zn content in plant leaves varied seasonally with a maximum rate of 120.63 mg · kg-1 observed in spring,and maximum content of Cu,Pb and Cd observed in winter.(2) Pb and Cu content in plant leaf is an extremely significant correlation,and no significant correlation between Pb and Zn,the total content of metal elements are significantly correlated to the content of Zn and Cd,both the correlation coefficients reached 0.85 above.From this study,it is possible to conclude that Pinus armandi can be used as remediation species in atmospheric Pb-polluted area,whereas Eucalyptus globulus and Yunnan pine can be selected as remediation species in Zn and Cu air polluted area.The four plants above mention have the significant capability in atmospheric Cd enrichment.The air pollution level of study area reached the pollution level of low-grade and the highest comprehensive atmospheric pollution index was observed in spring.