南亚热带滨海沙地3种林分类型凋落物的养分释放动态  

Nutrient release dynamics of litter in three forest types in coastal sandy land of south subtropical region

作　　者：刘易 曹雨虹 张艺帆 谢伟东[1] LIU Yi;CAO Yuhong;ZHANG Yifan;XIE Weidong(Forestry College,Guangxi University,Nanning,Guangxi 530004,China)

机构地区：[1]广西大学林学院,广西南宁530004

出　　处：《西北农林科技大学学报（自然科学版）》2022年第8期55-68,共14页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(31260093,31560061);广西自然科学基金项目(2013GXNSFAA019057);广西创新驱动发展重大专项项目(AA17204058)。

摘　　要：【目的】分析我国南亚热带滨海沙地3种林分类型凋落物的养分动态及养分归还量,揭示南亚热带滨海沙地不同森林生态系统的养分循环过程。【方法】在广西防城港滨海沙地的高山榕(Ficus altissima)/假苹婆(Sterculia lanceolata)天然林、红鳞蒲桃(Syzygium hancei)天然林和马占相思(Acacia mangium)人工林3种林分类型中设置凋落物收集网和分解袋,于2018年3月至2019年2月每月月底收取样品,对样品按叶、枝、花果和杂物进行分组,80℃烘干后测其质量及各组分C、N、P、K、Ca、Mg等养分元素的含量,对所测数据按需求经过整理计算后,分析不同林分类型年凋落物量、各养分含量及其月动态变化、各养分的年归还量特征和月动态变化以及不同组分各养分年归还量特征,最后对不同林分类型凋落物的C、N、P、K、Ca、Mg含量,C/N、C/P、N/P以及C、N、P归还量进行相关性分析。【结果】1)3种林分类型年凋落物量表现为高山榕/假苹婆天然次生林>红磷蒲桃天然林>马占相思人工林,凋落物中各养分元素含量大小均表现为C>Ca>N>K>Mg>P;3种林分类型凋落物间除C、Mg含量不存在显著差异(P>0.05)外,其余4种元素含量均差异显著(P<0.05)。2)3种林分类型凋落物各养分含量的月动态变化曲线分别呈双峰型、三峰型和多峰型,峰值一般出现在春季和秋冬季。3)3种林分类型凋落物的养分年总归还量和各元素归还量分别与其年凋落物量及养分含量大小排序相同,高山榕/假苹婆凋落物C、N、P、K、Mg归还量均最大;马占相思凋落物C、P、Ca归还量显著(P<0.05)小于红鳞蒲桃和高山榕/假苹婆,凋落物N、K、Mg归还量在3种林分类型间均存在显著差异(P<0.05);凋落叶的养分归还量在凋落物组分中占绝对优势。4)3种林分类型凋落物N含量与C/N均呈极显著负相关,P含量与C/P、N/P均呈极显著负相关,说明3种林分类型的生长器官在行使功【Objective】Nutrient dynamics and nutrient returns of litterfall in three forest types in coastal sandy land of south subtropical area in China were compared and analyzed to reveal nutrient cycling process in different forest ecosystems.【Method】Litter collection nets and decomposition bags were set up in three forest types of Ficus altissima/Sterculia lanceolata natural secondary forest,Syzygium hancei natural forest and Acacia mangium artificial forest in coastal sandy land of Fangchenggang,Guangxi.Samples were collected monthly from March 2018 to February 2019 and were grouped according to leaves,branches,flowers,fruits and scraps.After drying at 80℃,the total mass and contents of C,N,P,K,Ca,Mg and other nutrient elements of each component were measured.Then,the annual litter volume,nutrient content and monthly dynamic changes of different forest types,the annual return characteristics and monthly dynamic changes of nutrients as well as the annual return characteristics of nutrients in different components were analyzed.Finally,the correlations among contents of C,N,P,K,Ca and Mg,ratios of C/N,C/P and N/P as well as amounts of C,N and P returning were analyzed.【Result】1)The annual litter amounts of the three forest types were in the order of F.altissima/S.lanceolata natural secondary forest>S.hancei natural forest>A.mangium artificial forest,and the contents of nutrient elements in litter were in the order of C>Ca>N>K>Mg>P.The element contents were significantly different(P<0.05)except that there was no significant difference in the contents of C and Mg among litters.2)The monthly dynamic curves of nutrient contents of litter in three forest types were bimodal,trimodal and multimodal,and the peaks generally appeared in spring and autumn-winter.3)The annual return amounts of total nutrient and each element in the three forest types were in the same order.The maximum return amounts of C,N,P,K and Mg were obtained in F.altissima/S.lanceolata litter.The return amounts of C,P and Ca in A.mangium litter

关 键 词：滨海沙地 林分类型 凋落物 养分释放 生态化学计量 

分 类 号：S718.55[农业科学—林学]