亚热带森林72个常绿和落叶树种凋落叶重金属的富集效率  

Enrichment efficiencies of heavy metals in foliar litter of 72 evergreen and deciduous tree species in subtropical forests

作　　者：曾婉珍 艾灵 吴秋霞 张玉 朱晶晶 倪祥银 吴福忠 ZENG WanZhen;AI Ling;WU QiuXia;ZHANG Yu;ZHU JingJing;NI XiangYin;WU FuZhong(School of Geographical Sciences and Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China;Key Laboratory of Humid Subtropical Eco-Geographical Process of Ministry of Education,Fujian Normal University,Fuzhou 350117,China;Fujian Sanming Forest Ecosystem National Observation and Research Station,Sanming 365002,China)

机构地区：[1]福建师范大学地理科学学院,碳中和未来技术学院,福州350117 [2]福建师范大学湿润亚热带生态–地理过程教育部重点实验室,福州350117 [3]福建三明森林生态系统国家野外科学观测研究站,三明365002

出　　处：《中国科学:生命科学》2025年第3期563-574,共12页Scientia Sinica(Vitae)

基　　金：国家重点研发计划(批准号:2023YFF1305500);国家自然科学基金(批准号:32022056)资助。

摘　　要：为探究常绿树种与落叶树种凋落叶重金属的富集效率是否存在差异,以及这种差异是否与新鲜叶重金属的浓度有关,本研究通过亚热带森林样带配对采集了72种不同功能群的植物(常绿树种56种,落叶树种16种)新鲜叶和凋落叶,分别测定铁(Fe)、锰(Mn)、铜(Cu)、锌(Zn)、铅(Pb)、镉(Cd)和铬(Cr)的浓度,计算各重金属在凋落叶的富集效率.结果表明,常绿和落叶树种重金属均表现出明显的富集现象,富集效率分别为Fe(338.96%、230.04%)、Mn(26.90%、19.09%)、Pb(34.96%、34.00%)、Cd(197.50%、51.63%)、Cr(46.56%、26.75%),但在常绿和落叶树种之间的差异均不显著(P>0.05),Cu和Zn没有表现出明显的富集现象.凋落叶重金属的富集效率与新鲜叶中对应的重金属浓度密切相关,其中常绿树种凋落叶Fe、Cu、Zn、Pb、Cd和Cr的富集效率与新鲜叶中对应的重金属浓度呈显著负相关(P<0.05),落叶树种凋落叶Cu、Pb和Cr的富集效率与新鲜叶中对应重金属浓度呈显著负相关(P<0.05).这些结果表明,亚热带森林植物叶片在衰老过程中对Fe、Mn、Pb、Cd和Cr进行富集,并随凋落叶脱离植物体,以减少重金属对自身生理代谢活动的毒害,是植物权衡策略的重要体现.This study was designed to evaluate whether the enrichment efficiencies of heavy metals in foliar litter vary between evergreen and deciduous tree species and whether this variation is coupled with their concentrations in fresh leaves.Here we collected fresh and senescent leaves of 72 tree species(56 evergreen and 16 deciduous species)along subtropical forest transect in southern China,and determined the concentrations of iron(Fe),manganese(Mn),copper(Cu),zinc(Zn),lead(Pb),cadmium(Cd)and chromium(Cr),and calculated their enrichment efficiencies in foliar litter.We found that enrichment efficiencies of Fe(338.96%,230.04%),Mn(26.90%,19.09%),Pb(34.96%,34.00%),Cd(197.50%,51.63%)and Cr(46.56%,26.75%)were significantly enriched in foliar litter.However,the differences between evergreen and deciduous tree species were not significant(all P>0.05),and Cu and Zn were not enriched in foliar litter,either.The enrichment efficiencies of heavy metals in foliar litter were closely related to their concentrations in fresh leaves.Specifically,the enrichment efficiencies of Fe,Cu,Zn,Pb,Cd and Cr in evergreen trees showed significant negative correlations with their concentrations in fresh leaves(P<0.05),and the enrichment efficiencies of Cu,Pb and Cr in deciduous trees showed significant negative correlations with their concentrations in fresh leaves(P<0.05).In summary,Fe,Mn,Pb,Cd and Cr are enriched in foliar litter during leaf aging,and detached from the plants with litter fall to reduce the toxicity of these heavy metals to plant physiological and metabolic activities,which is an important trade–off mechanism for terrestrial plants.

关 键 词：重金属 富集效率 养分 亚热带森林 

分 类 号：S68[农业科学—观赏园艺]