杨、柳、榆、槐对淮北粉煤灰“土壤”中矿质积累的影响

The Accumulation of Poisonous Elements in Populus × euramericana ,Salix matsudana,Ulmus pumila and Robinia pseudoacacia Growing on Coal Ash“Soil”

利用火力发电厂排放的粉煤灰，１０ａ充填淮北煤矿塌陷区，其上覆盖约３０ｃｍ厚的潮土，形成特殊的“土壤”。１９８６～１９８７年营造了杨、柳、榆、刺槐人工林，在集约栽培条件下，生长发育正常。１９９１年调查了生物量和１４种元素在树体内积累和分布，结果表明，Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ等大量元素主要分布在树木的叶内，其次是根、树皮和侧枝，以树干的含量最低。在４个树种中，刺槐的含Ｎ量明显地高于其它３个树种。在有害的重金属元素中，Ｈｇ主要分布在根和树皮内，其次是叶、枝，树干极少；Ｎ主要分布在叶和树皮中，其次是枝和根，树干最少；Ｃｄ、Ｃｒ较为均匀地分布在各器官中。但Ｃｒ在根中的含量极高，原因有待查明。根据树木的生物量，以及各种元素在不同器官中的含量，估算了４个树种对“土壤”中营养元素和有毒元素的摄取量：４～５ａ树木摄取量Ｎ是１９５．２～５００．３ｋｇ／ｈｍ２，Ｐ为２１．９３～４４．８７ｋｇ／ｈｍ２，Ｐｂ和Ｈｇ分别为５５．２５～１０２．３２ｋｇ／ｈｍ２和０．８４９～３．４６２ｋｇ／ｈｍ２。最后，讨论了树木对环境的净化作用。

The speciai“soil”type condition is formed by filling the collapsed area withcoal ash from thermal power factory and covering 30 cm Chao soil onto the ash. In 1986～1987, Populus × euramericana, Salix matsudana,Ulmus pumila and Robinia pseudoacaciaplantations were established on the site. Under intensive cultivation,they grew well.Biomassand 14 elements distribution and accmulation,in the trees were investigated in 1991.The re-sult shows that most elements such as N,P, K,Ca,Mg were accumulated mainly in leaf,thenroot,bark and branch,their contents in trunk the least.Among the 4 species,Robinia pseu-doacacia had the highest N content.The accumulation of the poisonous elements in tree wasHg mainly in root and bark,seldom in leaf and branch;Pb mainly in leaf and bark,seldom intrunk;Cd and Cr distributed evenly in all organs. The absorption of nutritive and poisonouselements was calculated by their 4～5 years biomass and element contents. The trees purifica-tion function was discussed based on the calculation.