广西大瑶山国家级自然保护区不同海拔森林土壤有机碳矿化特征  

Characteristics of soil organic carbon mineralization under different altitude forest types in Dayaoshan National Nature Reserve of Guangxi,China

作　　者：黄远泽 胡彬 张凌睿 徐武 蒙检 卢峰 金恒 覃林[1] HUANG Yuan-ze;HU Bin;ZHANG Ling-rui;XU Wu;MENG Jian;LU Feng;JIN Heng;QIN Lin(Guangxi Key Laboratory of Forest Ecology and Conservation,College of Forestry,Guangxi University,Nanning 530004,China;Guangxi Forest Resources and Environment Monitoring Center,Nanning 530020,China;Laibin Jinxiu Dayaoshan Forest Ecosystem Observation and Research Station of Guangxi,Laibin 546100,China;Management Office for Dayaoshan National Nature Reserve of Guangxi,Jinxiu 545700,China)

机构地区：[1]广西大学林学院广西森林生态与保育重点实验室,广西南宁530004 [2]广西壮族自治区森林资源与生态环境监测中心,广西南宁530020 [3]来宾金秀大瑶山森林生态系统广西野外科学观测研究站,广西来宾546100 [4]广西大瑶山国家级自然保护区管理局,广西金秀545700

出　　处：《环境生态学》2025年第1期46-52,130,共8页Environmental Ecology

基　　金：广西高校大学生创新训练计划项目(202310593540);国家自然科学基金项目(31560109)资助。

摘　　要：研究不同海拔森林土壤有机碳矿化特征对于深入理解山地森林生态系统碳循环具有重要意义。以广西大瑶山国家级自然保护区不同海拔的常绿阔叶林(660 m)、针阔混交林(1430 m)和高山矮林(1750 m)为研究对象,基于各森林类型土壤(0~10 cm)室内25℃矿化培养试验,探讨南亚热带向中亚热带过渡区不同海拔森林土壤有机碳的矿化特征。结果表明,在40 d培养期内,高海拔森林土壤有机碳累积矿化量、矿化速率均显著高于低海拔森林土壤(p<0.05)。土壤有机碳(SOC)与土壤矿化速率正相关,含量更高的土壤有机碳提供了更多的矿化底物能够支持更高的微生物量,同时还有利于惰性土壤有机碳向易分解有机碳转化从而利于土壤有机碳的分解。全氮(TN)增加会显著降低反硝化功能基因丰度,增加土壤有效氮含量,促进微生物生物量增加,并促进微生物分泌获取能量的酶活性,有利于提高土壤有机碳矿化速率。不同海拔森林土壤有机碳矿化过程能用一阶动力学模型较好地拟合。海拔梯度上,土壤有机碳潜在矿化量(C_(p))高海拔森林土壤显著高于低海拔森林土壤,但土壤矿化速率常数(k)却是高海拔森林显著小于低海拔森林(p<0.05)。Mantle test和随机森林回归分析结果表明,TN和SOC是影响C_(p)的重要因素,而k主要受硝态氮(NO_(3)^(-)-N)和SOC的制约。总之,在全球气候持续变暖趋势下,该保护区高海拔森林土壤预计将释放更多的CO_(2),从而对大气条件产生较大影响。Investigating the characteristics of soil organic carbon mineralization in different altitude forest types is of great significance to deeply understand the carbon cycle of mountain forest ecosystems.Taking evergreen broadleaf forest(660 m),mixed broadleaf-conifer forest(1430 m),and alpine dwarf forest(1750 m)at different altitudes in Dayaoshan National Nature Reserve of Guangxi as the research objects,and the mineralization characteristics of soil organic carbon(SOC)in the transition zone from south to middle subtropics were examined based on the indoor 25℃mineralization incubation experiment of soil(0~10 cm)at each forest type.The results showed that the cumulative mineralization amount and mineralization rate of SOC from high-elevation forest soils were obviously greater than that from low-elevation forest soils during 40 d incubation period(p<0.05).SOC was found to be positively correlated with the rate of soil mineralisation.The higher content of soil organic carbon provided a greater quantity of mineralised substrate,which supported higher microbial populations.Furthermore,the conversion of inert soil organic carbon to readily decomposable organic carbon was facilitated,thereby contributing to the decomposition of soil organic carbon.A significant reduction in the abundance of denitrifying functional genes was observed in total nitrogen(TN),accompanied by an increase in the effective nitrogen content of the soil and a promotion of microbial biomass.Additionally,the secretion of energy-acquiring enzyme activities by microorganisms was facilitated,contributing to an increase in the rate of mineralisation of soil organic carbon.An increase in TN will result in a notable reduction in the abundance of denitrification genes,an elevation in the effective nitrogen content of the soil,and an enhancement in microbial biomass and microbial secretion of energy-acquiring enzymes.This is conducive to an increase in the rate of soil organic carbon mineralisation.The process of organic carbon mineralization in forest soi

关 键 词：森林类型 土壤有机碳 海拔 有机碳矿化 一阶动力学模型 

分 类 号：X171.1[环境科学与工程—环境科学]