二球悬铃木不同器官对空气中Cu、Ni、Pb和Zn的累积作用

Accumulation of different organs of Platanus acerifolia to Cu,Ni,Pb and Zn in air

以交通繁忙区(污染点)和相对清洁区(对照点)道路两侧的二球悬铃木〔Platanus acerifolia(Ait.)Willd.〕为研究对象,测定了不同器官(包括主干、老树皮、2年生枝条、1年生枝条、腋芽、叶片和果实)中Cu、Ni、Pb和Zn的含量,并对污染点二球悬铃木各器官中4种重金属元素的累积量和污染指数及二者的分布比例进行分析。结果表明:二球悬铃木体内重金属元素的含量因样点、器官及元素的不同而呈现不同的变化规律,污染点4种重金属元素的累积量及其分布比例、污染指数及其分布比例则因器官和元素的不同而有明显差异。总体上看,污染点各器官的Cu、Ni、Pb和Zn的含量均高于对照点且差异显著(P<0.05);4种重金属元素相比较,均以Zn含量最高,Cu含量次之,而Ni和Pb含量则较低;在不同器官中同一重金属元素的含量也有明显差异,其中,Cu、Ni和Zn含量均在腋芽中最高,Pb含量在2年生枝条中最高。4种重金属元素的累积量及其分布比例均在叶片中最高,在老树皮中次之,在1年生枝条、2年生枝条和腋芽中均较低;而4种重金属元素的污染指数及其分布比例则在老树皮中最高,在叶片中次之。研究结果显示:二球悬铃木各器官对空气中的重金属元素均有一定的吸滞能力,并且叶片和老树皮的吸滞能力明显优于其他器官。

Taking Platanus acerifolia （Ait.） Willd. on both sides of road in traffic busy area （pollution plot） and relatively clean area （the control plot） as research objects, contents of Cu, Ni, Pb and Zn in different organs including trunk, old bark, biennial branch, annual branch, axillary bud, leaf and fruit were determined, and cumulative amount and pollution index and their distribution proportion of four heavy metal elements in different organs of P. acerifolia at pollution plot were analyzed. The results show that heavy metal element contents in the body of P. acerifolia appear different change regulation because of differences in sampling plot, organ and element, and there are obvious differences in cumulative amount and its distribution proportion, pollution index and its distribution proportion of four heavy metal elements at pollution plot because of differences in organ and element. Overall, contents of Cu, Ni, Pb and Zn in each organ at pollution plot all are higher than those at the control plot with significant difference （P 〈 0.05 ）. Compared among four heavy metal elements, Zn content is the highest, Cu content takes the second place, while Ni and Pb contents are lower. And the content of same heavy metal element in different organs also has obvious difference, in which, contents of Cu, Ni and Zn in axillary bud all are the highest, and Pb content in biennial branch is the highest. Cumulative amount and its distribution proportion of four heavy metal elements all are the highest in leaf, secondly in old bark, lower in annual branch, biennial branch and axillary bud, while their pollution index and its distnbUtlOn proportion are the highest in old bark, secondly in leaf. It is indicated that organs of P. acerifolia all have a certain absorption capacity to heavy metal elements in air, and absorption capacities of leaf and old bark both are obviously better than those of other organs.