不同温度下杉木凋落叶分解过程中碳氮磷释放及其化学计量比变化  

Carbon,Nitrogen and Phosphorus Release and Their Stoichiometric Ratio Change During Decomposition of Cunninghamia lanceolata Leaf Litter at Different Temperatures

作　　者：邹志广 张马啸 黄小艳 张新阳 李树斌[1,3] 周丽丽 ZOU Zhi-guang;ZHANG Ma-xiao;HUANG Xiao-yan;ZHANG Xin-yang;LI Shu-bin;ZHOU Li-li(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,Fujian,China;College of Geography and Oceanography,Minjiang University,Fuzhou 350108,Fujian,China;Chinese Fir Engineering Technology Research Center of the National Forestry and Grassland Administration,Fuzhou 350002,Fujian,China;College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002,Fujian,China)

机构地区：[1]福建农林大学林学院,福建福州350002 [2]闽江学院地理与海洋学院,福建福州350108 [3]国家林业和草原局杉木工程技术研究中心,福建福州350002 [4]福建农林大学资源与环境学院,福建福州350002

出　　处：《林业科学研究》2024年第1期52-62,共11页Forest Research

基　　金：国家自然科学基金项目(32271864);福建省自然科学基金项目(2021J011045);福建省林业科学技术研究项目(2022FKJ30);福州市林业科技专项(榕财农(指)【2022】81号)。

摘　　要：[目的]研究升温对不同发育阶段杉木凋落叶分解过程中碳(C)、氮(N)、磷(P)释放规律及其生态化学计量特征的影响,揭示气候变暖背景下杉木人工林凋落叶分解过程中养分释放特征。[方法]收集中龄林(18年生)、成熟林(30年生)和过熟林(42年生)3个发育阶段的杉木凋落叶,设置25、30和35℃3个温度梯度进行室内模拟分解试验。[结果](1)在264 d的分解周期内,各发育阶段杉木凋落叶C、N、P残留率总体表现为随分解时间的增加而减小,但不同元素残留率变化模式不同,C残留率表现为释放—富集—释放模式,N残留率表现为富集—释放模式,P残留率表现为释放—富集模式。(2)拟合模型结果表明,成熟林与过熟林凋落叶分解过程中N周转期在35℃处理下比25℃处理分别缩短了34.4%和16.9%,P周转期分别缩短了38.4%和43.8%。(3)不同发育阶段杉木凋落叶分解过程中C:N、N:P比总体呈波动变化,C:P比呈先增大后减小的变化趋势,杉木凋落叶C:N、C:P、N:P比变幅分别为9.32~39.0、949~2194、32.7~153,升温处理在凋落叶分解过程总体上增大了C:P、N:P,降低了C:N比。[结论]温度升高能够缩短成熟林、过熟林凋落叶分解过程中N、P的周转期,提高各发育阶段杉木凋落叶分解过程中的C:P、N:P,说明杉木凋落叶分解明显受P限制,建议根据不同发育阶段杉木的生长需求,适当增加磷肥的施用。[Objective]To explore the effects of rising temperature on the release of carbon(C),nitrogen(N)and phosphorus(P)during leaf litter decomposition of Chinese fir at different developmental stages and their stoichiometric variations under the scenarios of climate warming.[Methods]The leaf litter of Chinese fir at three developmental stages,i.e.middle-aged forest(18-years old),mature forest(30-years old)and overmature forest(42-years old),was collected for decomposition experiments at three temperature treatments(i.e.,25,30 and 35℃).[Results](1)During the 264-day decomposition period,the residual rates of C,N and P in leaf litter at each development stage generally decreased over time.The residual rates of C,N and P showed patterns with release-enrichment-release,release-release,and release-enrichment,respectively.(2)The results of Olson fitting model revealed that the N turnover time of mature forest and over-mature forests during litter decomposition was shortened by 34.4 and 16.9%,respectively under 35℃compared with 25℃.In comparison,the P turnover time was shortened by 38.4%and 43.8%,respectively.(3)During litter decomposition,the ratios of C∶N and N∶P generally fluctuated,and C∶P increased first and then decreased.The variation of C∶N,C∶P and N∶P ratios were 9.32-39.0,949-2194 and 32.7-153,respectively.In the decomposition process of leaf litter,rising temperature increased C∶P,N∶P,and decreased C∶N.[Conclusion]Rising temperature can shorten the turnover rate of N and P during litter decomposition in mature and overmature forests by increasing C∶P and N∶P ratios during litter decomposition,indicating that litter decomposition of Chinese fir is obviously limited by P.It is suggested to appropriately increase the application of P fertilizer according to the growth needs of Chinese fir at different developmental stages.

关 键 词：杉木 不同发育阶段 凋落叶 温度升高 碳氮磷含量 化学计量比 

分 类 号：S714.2[农业科学—林学]