茂兰喀斯特森林倒木呼吸特征及呼吸速率模型构建  

Respiratory characteristics and models construction of fallen woods in Maolan Karst Forests

作　　者：赵祖燕 王科 戚玉娇 ZHAO Zuyan;WANG Ke;QI Yujiao(College of Forestry,Guizhou University,Guiyang 550025,China;Kaiyang County Nanmudu Town Agriculture and Rural Comprehensive Service Center,Guiyang 550025,China)

机构地区：[1]贵州大学林学院,贵阳550025 [2]开阳县楠木渡镇农业农村综合服务中心,贵阳550025

出　　处：《生态学报》2025年第4期1890-1899,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(32060266);贵州省科技计划项目(黔科合基础-ZK[2024]重点005)。

摘　　要：倒木是森林碳库的重要组成部分,其呼吸释放的CO_(2)对全球气候变化和碳循环具有重要意义。采用动态密闭气室分析法(EGM-4便携式环境气体检测系统连接自制腔室)对贵州茂兰喀斯特常绿落叶阔叶混交林中分别处于轻度、中度和重度腐烂等级的狭叶润楠(Machilus rehderi)、细叶青冈(Cyclobalanopsis gracilis)、化香(Platycarya strobilacea)和枫香(Liquidambar formosana)4种常见树种倒木呼吸进行日、季节动态监测,分析时间、树种、腐烂程度、倒木温度和倒木基质特性对倒木呼吸速率的影响,提取影响倒木呼吸速率的关键性影响因子,并以单木作为随机效应构建倒木呼吸速率与各影响因子的线性混合效应模型。结果表明:1)喀斯特森林不同树种倒木呼吸的年变化均表现出一致的单峰曲线模式,最大值出现在夏季(平均1.14 g CO_(2)m^(-2)h^(-2)),最小值出现在冬季(平均0.13 g CO_(2)m^(-2)h^(-2))。2)倒木呼吸速率受到季节因素的显著影响(P<0.001),且季节、树种、腐烂程度之间存在显著的交互效应(P<0.01)。倒木呼吸速率与倒木温度、倒木初始氮含量呈显著正相关,与倒木含水量呈显著负相关。3)考虑单木水平随机效应的混合模型拟合精度(R^(2)=0.90,AIC=125.241,BIC=146.082)优于扩展模型(R^(2)=0.83,AIC=139.062,BIC=152.881)和基础线性模型(R^(2)=0.73,AIC=151.660,BIC=159.476)。本研究揭示了倒木呼吸速率的年动态特征及其主要影响因素,强调了腐烂程度和环境因素对倒木CO_(2)释放的重要作用。这些结果为喀斯特森林碳循环的深入研究提供了重要依据,也为森林碳模型的改进提供了数据支持。Fallen wood constitutes a critical component of the forest carbon pool,and the CO_(2)emitted through its respiration is of great significance to global climate change and carbon cycle.In-depth study of the changing characteristics of respiration rate of fallen wood and its influencing factors can help to improve the understanding of the carbon dynamics of forest ecosystems.Karst forest is a natural forest with strong originality and more fallen woods in China,but the understanding of the respiratory model and driving factors of karst forest fallen woods is still unclear.Fallen woods are vital part of forest carbon pool,and the CO_(2)released by their respiration is relevant to global climate change and carbon cycle.The dynamic closed-air chamber analysis method,utilizing the EGM-4 portable environmental gas detection system linked to a self-made chamber,was employed to monitor the daily and seasonal respiration dynamics of fallen woods from four prevalent tree species(Machilus rehderi,Cyclobalanopsis gracilis,Platycarya strobilacea,and Liquidambar formosana)at varying decay stages in karst evergreen and deciduous broad-leaved mixed forests.We assessed the impacts of time,tree species,decay degree,and physicochemical properties on the respiration rate of fallen wood,identified the principal factors influencing this rate,and developed a linear mixed-effects model incorporating these factors,with individual pieces of wood treated as a random effect.The results indicated:1)The annual respiration variation of fallen wood from different tree species in karst forests exhibited a uniform pattern of single-peaked curves,peaking in summer(average 1.14 g CO_(2)m^(-2)h^(-2))and bottoming out in winter(average 0.13 g CO_(2)m^(-2)h^(-2)).2)The respiration rate of fallen wood was profoundly influenced by seasonal factors(P<0.001),with a notable interactive effect observed among seasons,species,and decay degree(P<0.01).The respiration rate of fallen woods was positively correlated with the temperature and initial elemental nitro

关 键 词：喀斯特森林 倒木 呼吸速率 影响因素 线性混合模型 

分 类 号：S718.5[农业科学—林学]