模拟降水减少对亚热带杉木人工林不同深度土壤CH_(4)吸收能力的影响  

The Effects of Simulated Reduced Precipitation on Soil CH_(4)Uptake Capacity at Different Depths in Subtropical Cunninghamia lanceolata Plantation

作　　者：万冬梅 陈匆琼[1,2] 杨智杰 陈仕东[1,2] WAN Dong-mei;CHEN Cong-qiong;YANG Zhi-jie;CHEN Shi-dong(College of Geographic Sciences/Carbon-Neutral Institute of Future Technology,Fujian Normal University,Fuzhou,Fujian 350007,China;Fujian Sanming Forest Ecosystem and National Field Scientific Observatory,Sanming,Fujian 365002,China)

机构地区：[1]福建师范大学地理科学学院/碳中和未来技术学院,福建福州350007 [2]福建三明森林生态系统与国家野外科学观测研究站,福建三明365002

出　　处：《林业科学研究》2025年第1期86-94,共9页Forest Research

基　　金：国家自然科学基金项目31930071;国家自然科学基金项目32271727。

摘　　要：[目的]土壤水分是影响森林土壤CH_(4)吸收能力的关键因子。探究降雨减少对不同土层CH_(4)吸收的影响,对森林温室气体研究具有重要意义。[方法]以亚热带杉木人工林为研究对象,在野外模拟自然降水减少实验(对照、降水减少20%、60%、100%),结合室内原状土培养实验探究降水减少对森林不同土层CH_(4)吸收能力的影响。[结果]表层土壤CH_(4)吸收能力最强,干旱程度的加深使得土壤CH_(4)吸收增加,随着土层的降低CH_(4)吸收能力也降低。不同土层间的土壤CH_(4)吸收速率存在显著差异(p<0.05),不同减水处理土壤CH_(4)吸收速率仅在表层土壤(0~5 cm)表现出显著差异(p<0.05),其他土层土壤CH_(4)吸收速率差异不显著,表明降水减少处理后土壤CH_(4)吸收速率差异主要是由于0~5 cm的土壤吸收能力不同造成的。表层土壤(0~5 cm)CH_(4)吸收速率与铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)呈正相关(p<0.05);不同土层的CH_(4)吸收速率与土壤有机碳(SOC)、可溶性有机碳(DOC)含量极显著正相关(p<0.001)。[结论]本研究中降雨减少引起的表层土壤NH_(4)^(+)-N、NO_(3)^(-)-N含量的增加促进了土壤对大气CH_(4)的吸收速率,土壤中SOC、DOC含量是调控不同土层CH_(4)吸收速率的关键因子。[Objective]Soil moisture is a key factor affecting the CH_(4)uptake of forest soils.It is important to investigate the impact of reduced precipitation on CH_(4)uptake in different soil layers for advancing forest greenhouse gas research.[Method]The study was conducted in an in-situ Cunninghamia lanceolata plantation to explore the effects of precipitation reduction on CH_(4)uptake across various soil layers.A throughfall gradient exclusion experiment was implemented with four treatments:control(CT),20%reduction(-20),60%reduction(-60),and total exclusion(-100).[Result]CH_(4)uptake rates varied significantly with soil depth,peaking in the topsoil and decreasing with increasing soil depth.The uptake increased with drought severity,showing significant variation among different soil layers(p<0.05).However,significant differences in CH_(4)uptake under varied throughfall gradient exclusion treatments were only observed in the 0-5 cm depth(p<0.05),with no significant differences in deeper soil layers.This implied that the change in CH_(4)uptake of throughfall exclusion treatments was mainly attributed to the distinct uptake capacity of the topsoil.Topsoil(0~5 cm)CH_(4)uptake positively correlated with NH_(4)^(+)-N and NO_(3)^(-)-N contents(p<0.05).CH_(4)uptake was significantly correlated with SOC and DOC(p<0.001)in each soil layer.[Conclusion]Overall,our findings indicate that throughfall exclusion led to increased NH_(4)^(+)-N and NO_(3)^(-)-N contents in the topsoil,which in turn enhanced CH_(4)uptake.Moreover,the contents of SOC and DOC play pivotal roles in modulating CH_(4)uptake across soil layers.

关 键 词：降水减少 土壤CH_(4)吸收 铵态氮 硝态氮 土壤有机碳 可溶性有机碳 

分 类 号：S714[农业科学—林学]