长苞铁杉林倒木不同结构组分难降解物含量的分解程度差异  

Differences in the Decomposition Degree of the Content of Refractory Substances in Different Structural Components of Fallen Wood in Tsuga longibracteata Forest

作　　者：邹向飞 黎棕仁 肖石红 何东进[1,2] 游巍斌 ZOU Xiang-fei;LI Zong-ren;XIAO Shi-hong;HE Dong-jin;YOU Wei-bin(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou,Fujian,350002,China;Fujian Southern Forest Resources and Environmental Engineering Technology Research Center,Fuzhou,Fujian,350002,China;Guangdong Provincial Key Laboratory of Silviculture,Protection and Utilization,Guangzhou,Guangdong,510520,China;Guangdong Academy of Forestry,Guangzhou,Guangdong,510520,China;College of Juncao Science and Ecology,College of Carbon Neutrality,Fujian Agriculture and Forestry University,Fuzhou,Fujian,350002,China)

机构地区：[1]福建农林大学林学院,福建福州350002 [2]福建省南方森林资源与环境工程技术研究中心,福建福州350002 [3]广东省森林培育与保护利用重点实验室,广东广州510520 [4]广东省林业科学研究院,广东广州510520 [5]福建农林大学菌草与生态学院碳中和学院,福建福州350002

出　　处：《林业科学研究》2024年第5期65-73,共9页Forest Research

基　　金：国家自然科学基金(31370624)。

摘　　要：[目的]探究倒木不同结构组分难降解物含量的分解程度差异,为长苞铁杉林科学经营提供理论依据。[方法]以福建省天宝岩国家级自然保护区中的长苞铁杉林倒木为对象,采用空间代替时间法,在4种林分类型(长苞铁杉纯林、长苞铁杉+阔叶树混交林、长苞铁杉+猴头杜鹃混交林、长苞铁杉+毛竹混交林)中,探究倒木不同结构组分(树皮、边材、心材)的难降解物含量在分解过程中的变化趋势。[结果]显示:(1)在倒木分解过程中,纤维素、总酚和缩合单宁含量降低,木质素含量升高;倒木缩合单宁含量除了在长苞铁杉+阔叶树混交林中随腐烂等级增加呈先升后降趋势外,在其它3种林分类型中均呈现逐渐下降趋势;(2)从第Ⅰ腐烂等级到第Ⅴ腐烂等级,长苞铁杉倒木的难降解物质含量变化均为显著,其中树皮、边材和心材的纤维素含量分别下降100.08 g·kg^(-1)(20.6%)、73.79 g·kg^(-1)(15.0%)和89.87 g·kg^(-1)(17.5%);木质素含量分别升高42.53 g·kg^(-1)(37.7%)、36.71 g·kg^(-1)(37.9%)和22.25 g·kg^(-1)(22.0%);缩合单宁含量分别下降34.45 g·kg^(-1)(47.4%)、11.02 g·kg^(-1)(23.5%)和16.83 g·kg^(-1)(44.0%);总酚含量分别下降4.87 g·kg^(-1)(57.6%)、1.78 g·kg^(-1)(32.0%)和2.06 g·kg^(-1)(41.7%)。[结论]长苞铁杉林倒木分解中难降解物含量除了与其自身C、N、P含量有关外,还受到林分类型及其结构组分与林分类型交互作用的综合影响。研究结果为指导长苞铁杉林分经营提供了理论依据。[Objective]This study aimed to investigate the variation in the decomposition degree of refractory substances in different structural components of fallen wood and provide a theoretical basis for the scientific management of Tsuga longibracteata forests.[Method]Based on the fallen wood from Tsuga longibracteata forests within the Tianbaoyan National Nature Reserve of Fujian Province,the space-for-time substitution method was employed to examine changes in the content of refractory substances within different structural components(bark,sapwood,and heartwood)of fallen wood across four forest types(T.longibracteata pure forest,T.longibracteata+broad-leaved mixed forest,T.longibracteata+R.simiarum mixed forest,T.longibracteata+P.pubescens mixed forest)during the decomposition process.TChanges in the content of refractory substances within different structural components(bark,sapwood,and heartwood)of fallen wood were investigated throughout the decomposition process.[Results]Results showed that:(1)During the decomposition process of fallen logs,the contents of cellulose,total phenols,and condensed tannins decreased,while the content of lignin increased.The condensed tannin content of fallen wood exhibited a gradual downward trend in the other three forest types except for the T.longibracteata+broad-leaved mixed forest,which showed an initial increase followed by a decrease with the increase of decay level.(2)There was a significant change in the content of recalcitrant substances in the fallen wood of Tsuga longibracteata.with a decrease of 100.08 g·kg^(-1)(20.6%),73.79 g·kg^(-1)(15.0%)and 89.87 g·kg^(-1)(17.5%)in the cellulose content of bark,sapwood and heartwood,respectively.The lignin content increased by 42.53 g·kg^(-1)(37.7%),36.71 g·kg^(-1)(37.9%)and 22.25 g·kg^(-1)(22.0%),respectively.The condensed tannin content decreased by 34.45 g·kg^(-1)(47.4%),11.02 g·kg^(-1)(23.5%)and 16.83 g·kg^(-1)(44.0%),respectively.The total phenolic content decreased by 4.87 g·kg^(-1)(57.6%),1.78 g·kg^(-1)(32.0%)and 2.06

关 键 词：长苞铁杉林 倒木 难降解物 结构组分 林分类型 

分 类 号：S718.5[农业科学—林学]