有机物覆盖对柳树微插穗萌条重金属提取的影响

EFFECT OF ORGANIC COVER ON PHYTOEXTRACTION OF HEAVY METALS BY RESPROUTERS OF WILLOW MICRO-CUTTINGS

为了提高种植效率、降低修复成本,本研究在野外条件下采用柳树直径0.8~1.5 cm、长度5 cm的微插穗为研究对象开展定植试验,比较不同有机物覆盖下微插穗生长及重金属Cu、Pb、Zn积累的差异,初步探究2种柳树微插穗定植及其重金属提取效果。结果表明:与未覆盖处理(C_(0))相比,有机物覆盖促进柳树微插穗繁殖和生长,显著提高萌条数量和生物量,增加萌条的长度和直径生长,竹柳的效果优于金丝柳;有机物覆盖的柳树萌条重金属含量略有降低,且单根萌条重金属提取量受有机物覆盖影响也较小,但样方内重金属总提取量显著增加,枝叶粉碎物堆肥覆盖处理的竹柳Cu、Pb、Zn总提取量分别提高5.5,23.0,4.4倍,金丝柳分别提高1.5,3.7,1.8倍。因此,从萌条数量、生物量、重金属总提取量来看,枝叶粉碎物堆肥覆盖处理的柳树微插穗植物提取效果最佳,是一种非常经济可行的植物修复措施。

In order to improve planting efficiency and reduce the remediation cost,the micro cuttings with a diameter of 0.8-1.5 cm and a length of 5cm of willow were used to perform the planting experiment in the field.After comparing of the growth and Cu,Pb and Zn accumulation of resprouters under different organic substrates,the phytoextraction efficiency of heavy metals was studied.The results showed that organic substrate cover could promote the propagation and growth of micro-cuttings in contrast to uncovered treatment.It significantly increased the number and biomass of resprouters but also promoted the length and diameter to certain content,the effect on Salix matsudana×alba was better than S.aureo-pendula.The heavy metal content of resprouter in plots covered by organic substrate was decreased slightly.The effect of organic substrate cover on amount of heavy metals phytoextracted by single resprouter was also less.However,the total amounts of heavy metals phtyoextraction in plot were increased significantly.Under the treatment by substrate of branches and leaves,total amount of Cu,Pb and Zn phytoextracted by S.matsudana×alba was increased 5.5 times,23.0 times and 4.4 times,and that of S.aureo-pendula was increased 1.5 times,3.7 times and 1.8 times respectively.Therefore,according to the number,biomass and total phtyoextraction amounts of resprouters,the best choice for planting and phytoremediation with willow micro-cuttings is using the substrate of branches and leaves,which is an very economic and feasible measure for phytoremediation.