马尾松与乡土阔叶树种混合凋落叶分解的质量损失  

Mass Loss of Mixed Leaf Litter with Pinus massoniana and Native Broad-leaved Species

作　　者：张艳 李勋 宋思梦 张健 ZHANG Yan;LI Xun;SONG Si-meng;ZHANG Jian(Research Center for Ecological Restoration and Characteristic Industry Cultivation in Hengduan Mountains Region,Sichuan Minzu College,Kangding 626000,Sichuan,China;Key Laboratory of Forestry Ecological Engineering in Sichuan,Collaborative Innovation Center of Ecological Security in the Upper Reaches of Yangtze River,Sichuan Agricultural University,Chengdu 611130,Sichuan,China)

机构地区：[1]四川民族学院,横断山区生态修复与特色产业培育研究中心,四川康定626001 [2]四川农业大学林学院生态林业研究所,生态林业工程重点实验室,长江上游生态安全协同创新中心,四川成都611130

出　　处：《林业科学研究》2022年第5期134-145,共12页Forest Research

基　　金：国家自然科学基金项目(31370628);国家科技支撑计划项目(2011BAC09B05);四川省科技支撑计划项目(12ZC0017)。

摘　　要：[目的]了解马尾松凋落叶与不同乡土阔叶树种凋落叶的混合分解特征,探明混合凋落叶的质量损失率与阔叶凋落叶的种类和所占比例之间的关系。[方法]本文以针叶马尾松(P)与乡土阔叶树种香樟(C)、檫木(S)以及香椿(T)凋落叶为研究对象,采用凋落叶分解袋法在野外进行2 a的针阔混合分解实验,通过将上述4个树种凋落叶按照1针1阔、1针2阔和1针3阔组合(即PC、PS、PT、PSC、PST、PCT和PSCT)且每种组合设置不同混合比例,共得到31个混合处理,研究这31个混合处理和4种纯凋落叶(合计35种处理凋落叶)的质量损失变化特征。[结果]分解2 a后,PT、PC、PCT、PST以及PSCT组合的质量损失率高于PS和PSC组合。混合凋落叶的质量损失率基本表现为协同效应且随分解时间的延长呈先增强后减弱的趋势,在分解18个月时最强(67.74%),相对于其它混合处理,PT、PCT和PSCT质量比分别为6:4、7:2:1和7:1:1:1时的质量损失率在4个分解时期均表现出较强的协同效应。PLS回归分析表明,凋落叶的分解系数k值和混合效应均与凋落叶的初始总酚含量、木质素含量、纤维素含量、C/N、C/P、木质素/N以及木质素/P表现为显著的负相关,与初始N和P含量表现为显著的正相关。[结论]总体上看,阔叶所占比例为30%~40%时,尤其是含有香椿(T)的混合凋落叶(PT,PST,PCT和PSCT)有利于促进马尾松凋落叶分解和林地养分循环。[Objective]To understand the mixed litters decomposition characteristics of Pinus massoniana and native broad-leaved trees,and the relationship between the mass loss rate of mixed litter with the species and proportion of broad-leaved litter.[Method]Based on the leaf litter of Pinus massoniana Lamb.(P),Cinnamomum camphora Presl.(C),Sassafras tzumu Hemsl.(S)and Toona sinensis Roem.(T),we conducted a two-year field needle-width mixed decomposition experiment of litter bags to study the mass loss of the pure litter of the above four tree species and their mixed litter,i.e.,combining needles of one conifer with leaves of one,two or three broad-leaved species(i.e.,PC,PS,PT,PSC,PST,PCT and PSCT,respectively),as well as including various ratios of these mixed litters in each treatment.There was a total of35 treatments,including 31 mixed and 4 pure litter treatments.[Result]After two years of decomposition,the combinations of PT,PC,PCT,PST and PSCT had higher mass loss rates of than PS and PSC.The mass loss rate of leaf litters generally showed a synergistic effect and it increased from the 6th to 18th month,and then declined thereafter.It was the highest(67.74%)at the 18th month of decomposition.Compared with other mixed litters,the mass loss rate of PT64,PCT721 and PSCT7111 showed a strong synergistic effect in 4 incubation periods.The results of regression analysis showed that the decomposition coefficient k and mixing effect were negatively correlated with the initial contents of total phenolic,lignin,cellulose,the ratios of C/N,C/P,lignin/N,and lignin/P.In contrast,they were positively correlated with the initial contents of N and P.[Conclusion]Our results show that mixed litters with 30%-40%broadleaved species,especially with the litter of T.sinensis,may benefit the litter mass loss of P.massoniana and promote the nutrient return to forest soils.

关 键 词：马尾松低效林 质量损失 乡土树种 混合凋落叶分解 协同效应 

分 类 号：S718.55[农业科学—林学]