杉木人工林土壤微团聚体中铁铝氧化物与微生物的分布及其关系  

Distribution and Relationships Regarding Fe,Al Oxides,and Microorganisms in Soil Microaggregates of Chinese Fir Plantation

作　　者：黄荣珍[1] 王金平 朱丽琴[1] 黄国敏[1] 申思佳 李燕燕[1] 万鸿宇 吴昊泽 Huang Rongzhen;Wang Jinping;Zhu Liqin;Huang Guomin;Shen Sijia;Li Yanyan;Wan Hongyu;Wu Haoze(Jiangxi Key Laboratory for Restoration of Degraded Ecosystems&Watershed Ecohydrology,Nanchang Institute of Technology,Nanchang,Jiangxi 330099,China)

机构地区：[1]南昌工程学院江西省退化生态系统修复与流域生态水文重点实验室,江西南昌330029

出　　处：《水土保持通报》2022年第1期1-9,共9页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“外源有机碳对红壤退化地微团聚体形成和稳定的影响机制”(31660192);江西省教育厅科学技术研究项目(GJJ161093)。

摘　　要：[目的]探究亚热带红壤区土壤微团聚体中铁铝氧化物与微生物的分布及其关系,为该区域土壤结构的改良提供理论依据。[方法]以亚热带红壤区典型林分杉木人工林为对象,研究不同粒级微团聚体胶结物中铁铝氧化物含量、结合态有机碳含量和微生物群落多样性在不同土层中的分布,并分析各形态铁铝氧化物含量与微生物群落多样性的关系。[结果]微团聚体中不同形态铁铝氧化物含量呈现:游离结晶态(Fe_(d),Al_(d))>>无定形(Fe_(o),Al_(o))>络合态(Fe_(p),Al_(p))。从总体上看,铁铝氧化物含量随微团聚体粒径的减少而逐渐增大,络合态铁(Fe_(p))和游离态铝(Al_(d))含量随土层深度的增加而逐渐降低,络合态铝(Al_(p))含量则是底层远高于表层。细菌、革兰氏阳性菌、革兰氏阴性菌是该林地的主要微生物,各类微生物PLFAs在土壤表层受粒径影响最大,且在粒径为50~200μm的微团聚体中含量最高。微团聚体中微生物丰富度、香农指数和辛普森指数总体上均是表层土壤最高,粒径最小的微团聚体微生物丰富度、香农指数最高。冗余分析(RDA)显示,放线菌磷脂脂肪酸(PLFAs)含量、革兰氏阳性菌PLFAs含量、香农指数、辛普森指数与游离态铁(Fe_(d))含量呈极强负相关关系,细菌PLFAs含量与Al_(d)含量、非晶型铝(Al_o)含量呈出极强的正相关关系,真菌、细菌、革兰氏阴性菌和丛枝菌根真菌PLFAs含量与铁铝键结合态有机物[Fe(Al)-SOC]含量均呈负相关。[结论]杉木林红壤微团聚体中铁铝氧化物与微生物的分布受土层和粒级影响,不同种类的微生物与不同形态的铁铝氧化物和结合态有机碳的相关性强弱不同。[Objective]The distribution of Fe,Al_(o)xides,and microbial community diversity in red soil microaggregates,and their relationships were studied in order to provide a theoretical basis for the improvement of subtropical red soil structure.[Methods]This study was conducted on a chinese fir plantation,which is the typical plant stand in the subtropical red soil region.The contents of Fe,Al_(o)xides,bonded organic matter,and microbial communities of different soilmicroaggregate grain sizes in different soil layers (topsoil,0—10 cm;middle soil,10—20 cm;subsoil,20—30 cm)were measured.Their relationships were analyzed by the redundancy analysis method(RDA).[Results]Different forms of Fe,Al_(o)xide contents in soil micro-aggregates were present in the following order:dithionite-citrate-bicarbonate-extractable oxides(Fe_(d),Al_(d))acid ammonium oxalate-extractable oxides(Fe_(o),Al_(o))>sodium pyrophosphate-extractable oxides(Fe p,Al p).In general,Fe and Al_(o)xide contents increased slowly with decreasing soil micro-aggregate grain sizes.The Fe p and Al_(d) contents decreased slowly with increasing soil depth,and Al p content in the subsoil was far greater than in the topsoil.The main microorganisms in the chinese fir plantation soil were bacteria,and gram-positive and negative bacteria.The effect of micro-aggregate grain size on microorganisms was greater in topsoil than in middle soil and subsoil.The phospholipid fatty acids(PLFAs)of microorganisms in soil micro-aggregates of 50—200μm diameter were greater than in micro-aggregates of other diameters.The richness,Shannon index,and Simpson index of microorganisms were greatest in topsoil,and the richness and Shannon index of microorganisms were greatest in soil micro-aggregates with the lowest diameter.RDA revealed that antino bacteria PLFAs,gram-positive bacteria PLFAs,and microbial Shannon and Simpson indexes were highly significantlyand negatively correlated with Fe_(d).Bacteria PLFAs showed highly significant positive relationships with Al_(d) and Al_(o) con

关 键 词：土壤微团聚体 铁铝氧化物 微生物群落 杉木人工林 

分 类 号：S714[农业科学—林学]