摘要
[目的]研究苦竹新鲜残体的分解过程及影响因素可以预测苦竹林在受到极端气候事件导致的机械损伤后生态系统物质循环变化过程,评估灾害对森林碳汇功能的影响,为灾后森林科学管理提供依据。[方法]以广东南岭地区皆伐后苦竹大量扩张的次生林为对象,设置对照(CK)和移除林下竹子(RB)两种林内环境,采用分解袋法研究了苦竹各器官新鲜残体的分解特征。[结果]苦竹各器官新鲜残体的分解过程可以分为两个阶段,即前期阶段(前2个月)质量快速损失,后期阶段(后24个月)缓慢分解。前期阶段各器官平均质量损失率依次为竹叶(51.2%)>竹枝(31.7%)>竹根(24.4%)>竹秆(16.6%),各器官间均存在显著差异(P<0.05),RB环境下竹叶的质量损失率显著低于CK。后期阶段各器官平均质量损失率依次为竹枝(40.3%)>竹叶(29.1%)>竹秆(28.1%)>竹根(19.6%),各器官间除竹叶与竹秆外均存在显著差异,RB环境下竹枝的质量损失率显著高于CK,竹根的质量损失率显著低于CK。Olson分解模型能够较好地模拟各器官的分解过程,平均分解系数(k)依次为竹叶(0.891)>竹枝(0.554)>竹秆(0.249)>竹根(0.242),各器官间除竹秆和竹根外均存在显著差异,RB环境下竹叶的k显著低于CK。各器官分解50%的周期(T_(0.5))依次为竹秆(2.48 a)>竹根(2.44 a)>竹枝(0.97 a)>竹叶(0.51 a),其中竹根和竹秆显著高于竹枝和竹叶,RB环境下竹根的T_(0.5)显著高于CK。各器官分解周期(T_(0.95))依次为竹根(12.81a)>竹秆(12.12 a)>竹枝(5.22 a)>竹叶(3.22 a),其中竹根和竹秆显著高于竹枝和竹叶,RB环境下竹秆的T0.95显著低于CK,竹根的T_(0.95)显著高于CK。各器官基质质量与分解指标间的相关系数总体上表现为前期阶段高于后期阶段,CK环境下高于RB环境下,其中碳(C)、钾(K)、C/氮(N)、C/磷(P)与分解指标间相关系数较小,N、P、N/P与分解速率呈正相关,木质素/N与分解速率呈负相关。[结论]苦
[Objective]To study the decomposition process of fresh residues of Pleioblastus amarus(Keng)keng and its influential factors,predict the changes in processes of ecosystem material cycling in bamboo forests after being mechanically damaged by extreme climatic events,and assess the impacts of the dis-aster on the function of forest carbon sinks for providing a basis for the scientific management of forests after the disaster.[Methods]Based on the secondary forests,where P.amarus expanded greatly after clearcutting,in the Nanling area of Guangdong Province,two treatments including removal of understory bamboos(RB)and control(CK)were set uo to generate distinct in-forest environments,and the decom-position characteristics of fresh residues from various organs of P.amarus were studied using the decom-position bag method.[Results]The decomposition process of fresh residues of each organ of P.amarus could be divided into two stages,rapid mass loss in the early stage(first 2 months)and slow decomposi-tion in the later stage(last 24 months).The average mass loss rate of each organ in the early stage was in the order of leaves(51.2%)>twigs(31.7%)>roots(24.4%)>culms(16.6%),and there were significant differences(P<0.05)among all organs,with a significantly lower mass loss rate of leaves in RB environ-ment than that of CK.The average mass loss rate of each organ at the later stage was in the order of twigs(40.3%)>leaves(29.1%)>culms(28.1%)>roots(19.6%),and there were significant differences among the organs except for leaf and culm.The mass loss rate of branches in RB environment was significantly higher than that of CK,while the mass loss rate of roots was significantly lower than that of CK.The Olson decomposition model could well fit the decomposition processes of various organs.The average decom-position coefficient(k)of leaves(0.891)was the largest,followed by the twigs(0.554),culms(0.249),and roots(0.242).There were significant differences of the k among all organs except for culms and roots,and the k of leaves in RB en
作者
林大雪
赵厚本
黄春华
许伟华
李兆佳
周志平
LIN Da-xue;ZHAO Hou-ben;HUANG Chun-hua;XU Wei-hua;LI Zhao-jia;Zhou Zhi-ping(Guangdong Tianjingshan Forest Farm(Guangdong Tianjingshan National Forest Park Management Office),Ruyuan 512726,Guangdong,China;Research Institute of Tropical Forestry,Chinese Academy of Forestry,Guangzhou 510520,Guangdong,China;Guangdong Nanling National Nature Reserve,Ruyuan 512727,Guangdong,China;Nanling Beijiangyuan National Forest Ecosystem Research Station,Guangzhou 510520,Guangdong,China)
出处
《林业科学研究》
CSCD
北大核心
2024年第3期183-192,共10页
Forest Research
基金
广东省林业科技创新项目(2019KJCX026)
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2021SY002)。
关键词
苦竹
亚热带
次生林
凋落物分解
基质质量
林下环境
木质素/N
Pleioblastus Amarus
subtropical zone
secondary forest
litter decomposition
substrate quality
understory environment
lignin/N
