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2 期           杨帆等: 增温对川西亚高山冷杉林凋落叶分解过程中有机碳含量的短期影响                                            3 2 1

                                1ꎬ2            2ꎬ3             1ꎬ2                 2ꎬ4          2ꎬ5ꎬ6∗
                    YANG Fan ꎬ ZENG Xin ꎬ LIU Yuwei ꎬ YANG Jiaping ꎬ TAN Yu
               ( 1. College of Tourismꎬ Kaili Universityꎬ Kaili 556011ꎬ Guizhouꎬ Chinaꎻ 2. College of Forestry/ Center of Carbon Sink Researchꎬ Sichuan
               Agricultural Universityꎬ Chengdu 611130ꎬ Chinaꎻ 3. Chongqing Fuling District Forestry Bureauꎬ Chongqing 408099ꎬ Chinaꎻ 4. College of
                  Life Sciencesꎬ Mianyang Normal Universityꎬ Mianyang 621000ꎬ Sichuanꎬ Chinaꎻ 5. Guangxi Key Laboratory of Plant Conservation
                       and Restoration Ecology in Karst Terrainꎬ Guangxi Institute of Botanyꎬ Guangxi Zhuang Autonomous Region and
                         Chinese Academy of Sciencesꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 6. Guangxi Guilin Urban Ecosystem National
                                      Observation and Research Stationꎬ Guilin 541006ꎬ Guangxiꎬ China )

                 Abstract: Global warming profoundly impacts the decomposition of surface litter in terrestrial ecosystems. Understanding
                 the response of litter decomposition and its organic carbon components in alpine forests to warming is of great significance
                 for comprehending forest carbon turnover under climate change. To explore the short ̄term impact of warming ̄induced
                 hydrothermal changes on organic carbon components during litter decompositionꎬ a one ̄year in ̄situ decomposition
                 experiment was carried out in a subalpine fir forest in western Sichuan. The dynamic changes of leaf litter mass and its
                 organic carbon components were monitored through continuous sampling using simulated warming in an open ̄top chamber
                 (OTC). The results were as follows: (1) Compared with the controlꎬ simulated warming significantly increased soil
                 temperature (+0.55 ℃)ꎬ while significantly decreased litter water content by 7.46%ꎬ howeverꎬ it had no significant
                 effect on soil water content. (2) Simulated warming did not significantly change the mass remaining and the content of
                 major organic carbon components (such as total organic carbonꎬ hot water ̄soluble organic carbonꎬ and non ̄structural
                 carbon) of leaf litter. Howeverꎬ the content of dissolved organic carbon ( DOC)ꎬ dissolved sugarꎬ and starch was
                 significantly affected by the interaction between warming and the sampling periodꎬ indicating that litter mass remaining
                 and the content of most organic carbon components are not sensitive to short ̄term warming. (3) The partial least squares
                 structural equation model (PLS ̄SEM) analysis showed that although simulated warming did not alter the association
                 pathways among soil temperature and water contentꎬ litter massꎬ and organic carbon componentsꎬ it significantly
                 strengthened the negative correlation between litter water content and organic carbon components. This suggests that
                 future temperature increases in subalpine areas of western Sichuan may affect the input of litter organic carbon into soil as
                 a source of nutrients by altering the moisture status of surface litter. This study emphasizes that future research should
                 focus more on the impact of warming on litter moisture dynamics and its role in carbon turnover. These findings provide
                 an important basis for a deeper understanding of the carbon cycle in alpine ecosystems and for optimizing forest response
                 prediction models under future global climate change scenarios.
                 Key words: warmingꎬ litterꎬ organic matter decompositionꎬ organic carbonꎬ subalpine forest



                凋落物分解是森林生态系统物质循环和能量                            素和木质素等较复杂有机质开始缓慢分解ꎬ凋落
            流动的核心环节ꎮ 地上植物通过落叶和枯枝等形                             物中 的 大 分 子 碳 转 化 为 可 溶 性 有 机 碳 ( Don &
            式将有机质归还土壤ꎬ这一过程不仅维持着生态                              Kalbitzꎬ 2005)ꎻ后期ꎬ难分解有机质成为主要成
            系统内部的碳和养分循环ꎬ还在全球碳循环中发                              分ꎬ分解速率稳定维持在较低水平ꎬ同时凋落物有

            挥着 重 要 的 碳 汇 调 节 作 用 ( Yue et al.ꎬ 2016ꎻ           机质与土壤环境结合形成稳定的腐殖质ꎮ 该分解
            Krishna & Mohanꎬ 2017)ꎮ 凋落物分解过程中有机                 阶段意味着凋落物分解会在初期出现较大的质量
            碳的动态变化是评估生物地球化学循环的重要指                              损失和元素释放ꎮ 然而ꎬ在高寒地区针叶森林的
            标ꎬ其存留量和转化效率直接影响森林生态系统                              凋落物往往表现出难分解特征ꎬ以及微生物活性

            的固碳能力、碳的流动方向与速率 (Baldock et al.ꎬ                   较低的环境限制ꎬ使其分解过程延长 ( Xu et al.ꎬ
            2004)ꎮ 通常ꎬ凋落物分解具有阶段性特征:初期ꎬ                         2024)ꎮ 这导致针叶林凋落物将养分归还土壤的
            易分解的有机碳 ( 如碳水化合物和简单蛋白质)                            过程变得漫长ꎬ进而调控了森林生态系统生产力
            迅速被 微 生 物 利 用ꎬ 导 致 凋 落 物 质 量 快 速 下 降               (Canessa et al.ꎬ 2021)ꎮ 凋落物分解主要受初始
            (Krishna & Mohanꎬ 2017)ꎻ中期ꎬ纤维素、半纤维                 物质的化学成分和环境因子驱动ꎮ 一方面ꎬ凋落
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