摘要
[目的]旨在探明火烧迹地内凋落叶分解过程中全碳的释放特征,为川西北地区大面积分布的森林火烧迹地恢复树种筛选提供依据.[方法]以乡土树种高山松(Pinus densata,P)、高山栎(Quercus semicarpifolia,Q)以及冷杉(Abies fabri,A)凋落叶为研究对象,按照不同树种组合、不同质量比例组合设置17个处理(P、Q、A、PQ3∶1、PQ1∶1、PQ1∶3、PA3∶1、PA1∶1、PA1∶3、QA3∶1、QA1∶1、QA1∶3、PQA2∶2∶1、PQA2∶1∶1、PQA1∶1∶1、PQA1∶1∶2 和 PQA1∶2∶2)进行野外分解实验.[结果]①在8个月的分解过程中,火烧迹地内不同处理的凋落叶全碳均表现出富集现象,其中高山松(P)、冷杉(A)、PQ3∶1、QA3∶1、QA1∶1、PA1∶1、PQA2∶2∶1、PQA1∶1∶2 以及PQA1∶2∶2凋落叶的全碳含量随着分解时间的延长表现出先上升(0～4个月)再下降(4～8个月)的变化趋势,而高山栎(Q)、PQ1∶1、PQ1∶3、QA1∶3、PA3∶1、PA1∶3、PQA2∶1∶1和PQA1∶1∶1的全碳含量随着分解时间的延长表现出增加的趋势.②分解4个月后,大部分(85.71％)混合处理凋落叶全碳释放率的观测值-预期值＞0,其中PQ1∶1和QA3∶1表现出协同效应.分解8个月后,50％的混合凋落叶全碳释放率的观测值-预期值＜0,且主要出现在PA组合和部分PQA组合(2∶2∶1、2∶1∶1和1∶1∶1),其中PQA1∶1∶1表现出拮抗效应.③PLS回归分析表明,凋落叶初始全碳、全氮、全磷、纤维素、总酚含量以及C/N、N/P、C/P、纤维素/N、木质素/N、木质素/P与凋落叶碳释放的混合效应显著相关.[结论]总体上看,高山栎分别与高山松、冷杉混合时,尤其是高山松与高山栎凋落叶按照1∶1混合、高山栎和冷杉凋落叶按照3∶1混合时,更有利于其全碳释放.
Abstract
[Objective]The aim of this study is to reveal the release characteristics of total carbon during the decomposition process of leaf litter in burned areas,thereby providing a foundation for selecting ap-propriate tree species for the restoration of extensively distributed forest burned areas in northwest Sichuan.[Method]This research focused on the leaf litter of native tree species,specifically Pinus densata(P),Quercus semicarpifolia(Q)and Abies fabri(A).These species were combined into 17 treatments(P、Q、A、PQ3∶1、PQ1∶1、PQ1∶3、PA3∶1、PA1∶1、PA1∶3、QA3∶1、QA1∶1、QA1∶3、PQA2∶2∶1、PQA2∶1∶1、PQA1∶1∶1、PQA1∶1∶2 and PQA1∶2∶2)based on varying species combinations and mass ratios,fol-lowed by field decomposition experiments conduction.[Result]①During the 8-month decomposition process,different treatments of leaf litter in the burned area showed an enrichment of total carbon.Specifi-cally,the total carbon content of leaf litter for treatments P,A,PQ3∶1,QA3∶1,QA1∶1,PA1∶1,PQA2∶2∶1,PQA1∶1∶2 and PQA1∶2∶2 showed an initial increase(0-4 months),followed by a decrease(4-8 months)as decomposition progressed.In contrast,the total carbon content for treatments Q,PQ1∶1,PQ 1∶3,QA1∶3,PA3∶1,PA1∶3,PQA2∶1∶1 and PQA1∶1∶1 showed a continuous increase throughout the entire decomposition period.②After 4 months of decomposition,the total carbon release rate of the major-ity of mixed leaf litter(85.71％,calculated as observed value-expected value)was greater than 0,with PQ 1∶1 and QA3∶1 exhibiting a synergistic effect.Conversely,after 8 months of decomposition,the total carbon release rate of mixed leaf litter(50％,calculated as observed value-expected value)was less than 0,and predominantly observed in the PA and certain PQA combinations(2∶2∶1,2∶1∶1,and 1∶1∶1),with PQA1∶1∶1 showing an antagonistic effect.③PLS regression analysis showed that the initial content of C,N,P,cellulose,total phenols and the ratios of C and N,N and P,C and P,cellulose and N,lig-nin and N,lignin and P were significantly correlated with the mixed effect of carbon release from leaf lit-ter.[Conclusion]The synergistic effect of leaf litter decomposition is enhanced when Q.semicarpifolia(Q)is mixed with either P.densata(P)or A.fabri(A),thereby facilitating greater release of total carbon.
维普
万方数据