淋溶作用下桉树浸提液单宁对赤红壤铁形态影响  

Effect of eucalyptus extract tannins on iron morphology of lateritic red soil under leaching process

作　　者：曾海琪 宋书巧 赵婷 ZENG Haiqi;SONG Shuqiao;ZHAO Ting(School of Geographic Science and Planning,Nanning Normal University,Nanning 530100;School of Environment and Life Sciences,Nanning Normal University,Nanning 530100)

机构地区：[1]南宁师范大学地理科学与规划学院,南宁530100 [2]南宁师范大学环境与生命科学学院,南宁530100

出　　处：《环境科学学报》2024年第6期395-403,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金青年项目(No.42301073);广西科技基地和人才专项(No.桂科AD22080023)。

摘　　要：广西是桉树主要种植区之一.桉树凋落叶在降雨时期对土壤的淋溶作用造成的一系列生态环境问题引起广泛关注.本研究结合广西地区降雨酸度状况,调节3个不同pH的去离子水处理液提取桉树凋落叶浸提液模拟淋溶赤红壤,分析桉树凋落叶浸提液对赤红壤淋溶后淋出液pH值、色度、单宁和Fes变化以及赤红壤中pH、单宁和铁形态变化特征,探讨桉树凋落叶浸提液对赤红壤中铁形态影响,深入研究桉树凋落叶浸提液淋溶对赤红壤的影响.结果表明:桉树凋落叶浸提液淋溶赤红壤会导致淋出液水质变黑,浸提液浓度越高,色度越高、单宁和Fes淋出越多;淋溶后赤红壤表层滞留大量单宁,土壤中Fed与Feo、Fep、土壤单宁呈显著正相关关系,浸提液中的单宁促使赤红壤中Fed向Fes、Feo和Fep转化.不同pH值处理液浸提的桉树凋落叶对赤红壤淋溶作用影响显著,凋落叶中大量单宁与土壤中Fe3+结合导致赤红壤表土层和淋出液变黑.本研究明确了桉树单宁和铁形态在降雨淋溶下的迁移转化特征,为深入研究赤红壤地区桉树人工林种植生态管理提供参考.Guangxi is a key region for eucalyptus cultivation and the ecological and environmental issues arising from the leaching of eucalyptus litter into soil during rainfall have attracted extensive concern.This study,combineing the rainfall acidity level in Guangxi region,simulated eucalyptus litter extracts by adjusting deionized water to three different pH solutions to mimic the leaching process in lateritic red soil.The research analyzed the variations in pH,color,tannins,and iron(Fe)levels in the leachate from eucalyptus litter extracts on lateritic red soil,as well as the morphological changes in pH,tannins,and iron content within the lateritic red soil.The results showed that the leaching with eucalyptus litter extract caused the lateritic red soil solution to black.The higher the concentration of the extract,the darker the color,and the greater the leaching of tannins and iron(III)oxides.Post-leaching,a large amount of tannins remained on the surface layer of the lateritic red soil.There was a significant positive correlation between Feo,Fep,and soil tannins in the soil.With the increasing of the extracted concentration of the extract,the color darkened further,and more tannins and iron(III)oxides were leached.A large amount of tannins remained on the surface layer of the lateritic red soil after leaching.A significant positive correlation was obtained between Feo,Fep,with soil tannins in the soil.The tannins in the extract facilitated the transformation of Fed to Fes,Feo,and Fep in the lateritic red soil.In conclusion,eucalyptus litter with varing pH levels significantly influenced the leaching of lateritic red soil.The interaction between the abundant tannins in leaf litter and Fe3+in the soil resulted in the darkening of the topsoil layer and leaching solution of lateritic red soil.This study confirmed the transport and transformation patterns of eucalyptus tannins and iron forms under rainfall leaching,offering a reference for the ecological management of eucalyptus plantation forests in regions with lateri

关 键 词：桉树凋落叶 赤红壤 PH值 单宁 铁形态 

分 类 号：X171.1[环境科学与工程—环境科学]