Liu Yan-Ju, Ding Hui, Zhu Yong-guan
Beijing Centre for Physical and Chemical Analysis, Beijing 100089, China.
J Environ Sci (China). 2005;17(2):294-300.
The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory (BSF) and 17 plant species in the Beijing Botanical Garden (BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni, and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index (MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated (SA or grade I), moderately accumulated (MA or grade II), intermediately accumulated (IA or grade III), and weakly accumulated (WA or grade IV). The results showed that elemental association between Fe, Al, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viridis, Cotinus coggygria, Lespedeza floribunda, Rhamnus parvifolia, Lespedeza tomentosa.
对生长在北京钢铁厂（BSF）附近山丘上的21种植物以及北京植物园（BBG）的17种植物的土壤和叶片中的铁、锰、铝、锌、铅、镍、铬和砷浓度进行了测量。结果表明，根据中国自然背景阈值，BSF的土壤受到锌污染。与BBG相比，BSF的土壤存在镍和铬的金属污染。两个地点叶片中金属浓度的比较表明，一般来说，同一物种叶片中金属的积累在两个地点之间存在显著差异。即使在同一地点，每个物种的金属积累也存在显著差异。该研究旨在筛选具有净化土壤中有毒金属能力的园林植物，并为叶片制定了一个总体金属积累指数（MAI），然后对MAI进行分类，以便广泛应用于污染地区物种的选择。为此，MAI值范围分为四类：强积累（SA或I级）、中度积累（MA或II级）、中度积累（IA或III级）和弱积累（WA或IV级）。结果表明，采样点中，铁、铝、镍和砷之间的元素关联通常高度相关。这可能表明它们具有共同的生化特征。一般来说，在两个地点都具有强积累和中度积累的物种包括荆条（Vitex negundo）、构树（Broussonetia papyrifera）、榆树（Ulmus pumila）和茜草（Rubia cordifolia）。在BSF和其他具有类似生态系统的工业场地，强积累和中度积累的物种包括国槐（Sophora japonica）、光叶蛇葡萄（Ampelopsis aconitifolia var. glabra）、侧柏（Platycladus orientalis）、河蒴荛花（Wikstroemia chamaedaphne）、糙隐子草（Cleistogenes squarrosa）、扁担杆（Grewia biloba），在BBG中，除了狗尾草（Setaria viridis）、黄栌（Cotinus coggygria）、多花胡枝子（Lespedeza floribunda）、小叶鼠李（Rhamnus parvifolia）、绒毛胡枝子（Lespedeza tomentosa）。
