摘要
以秦岭太白山南坡为研究区域,海拔每隔50 m设置1个采样点,探究土壤有机碳分布的海拔梯度效应及驱动因素。结果表明,0~10 cm土层,海拔分区对土壤有机碳含量影响明显,随海拔的升高土壤有机碳含量呈递升趋势,表现为高山区[(108.2±46.89)g·kg^(-1)]>中山区[(96.72±65.02)g·kg^(-1)]>低山区[(39.74±8.68)g·kg^(-1)];气候带的影响亦集中于该土层,土壤有机碳含量呈现出亚寒带>寒温带>温带的分异特征;植被带的调控效应在该土层表现尤为清晰,土壤有机碳含量为高山灌丛草甸带>高山针叶林带>桦木林带>松栎混交林带>锐齿栎林带>混交林带。随土层深度的增加,土壤有机碳含量整体呈递降趋势,0~10 cm表层土壤的有机碳含量最富足。总土层深度也因海拔梯度发生分异[高山区(32.90 cm)>低山区(23.13 cm)>中山区(20.13 cm)];单位土层深度土壤有机碳含量体现中海拔优势[中山区(4.93 g·kg^(-1)·cm^(-1))>低山区(2.34 g·kg^(-1)·cm^(-1))>高山区(2.32 g·kg^(-1)·cm^(-1))]。除海拔分区、气候带、植被带和土层深度以外,呈现出土壤水分、土壤温度及土壤容重共同驱动土壤有机碳含量海拔梯度格局,其中,土壤水分贡献最大,是塑造中海拔区域碳汇热点的核心因子。而总土层深度作用不显著,说明中山区的碳汇优势并非由土层深度导致,而是土壤有机碳本身的高值驱动。
This study investigates the altitude gradient effect and driving factors of soil organic carbonSOC distribution on the southern slope of Taibai Mountain in Qinling Mountains,with sampling points established every 50 m along the altitudinal direction.Analysis of 0~10 cm surface soil data revealed that SOC content presented a distinct altitude-dependent increase,progressively decreasing from high-mountain areas[108.2±46.89 g·kg^(-1)]to mid-mountain areas[96.72±65.02 g·kg^(-1)]and low-mountain areas[39.74±8.68 g·kg^(-1)].The climatic zone also showed distinct differentiation,with SOC content exhibiting a pattern of subarctic zone>cold temperate zone>temperate zone.Vegetation belt effects were particularly evident,with SOC content ranking as alpine shrub meadows>alpine coniferous forests>birch forests>pine-oak mixed forests>sharp-toothed oak forests>mixed forests.Notably,SOC content decreased with the increase in soil depth,peaking in the 0-10 cm surface layer.Total soil depth also varied by altitude gradient,showing a pattern of high-mountain zone32.90 cm>low-mountain zone23.13 cm>mid-mountain zone 20.13 cm.SOC content per unit soil depth remained high in the mid-mountain zone,demonstrating a trend of mid-mountain zone4.93 g·kg^(-1)·cm^(-1)>low-mountain zone2.34 g·kg^(-1)·cm^(-1)>high-mountain zone2.32 g·kg^(-1)·cm^(-1).In addition to altitude,climatic zone,vegetation belt,and soil layer depth,this study demonstrated that soil moisturethe primary contributor,soil temperature,and soil bulk density collectively drove the altitude gradient pattern of SOC content,with moisture being the key factor shaping carbon sink hotspots in mid-altitude regions.The findings indicate that on the southern slope of Taibai Mountain in the Qinling Mountains,soil moisture is the critical driver of the altitude-dependent pattern of SOC content,while the total soil layer depth shows no significant effect.This suggests that the carbon sink advantage in the mid-mountain zone is not attributable to soil layer depth but rather driven by the inherently high levels of SOC.
作者
李晶
张彦军
成爱芳
党水纳
李天姿
LI Jing;ZHANG Yanjun;CHENG Aifang;DANG Shuina;LI Tianzi(College of Geography and Environment,Baoji University of Arts and Sciences,Baoji,Shaanxi 721013,China;Tourism College,Inner Mongolia Normal University,Hohhot,Inner Mongolia 010022,China;College of Education,Baoji University of Arts and Sciences,Baoji,Shaanxi 721013,China)
出处
《森林与环境学报》
北大核心
2026年第2期131-140,共10页
Journal of Forest and Environment
基金
国家自然科学基金青年项目“土壤微生物群落结构调控太白红杉林凋落物呼吸温度敏感性的机理研究”(41801069)。
关键词
土壤有机碳
土壤水分
海拔梯度效应
山地土壤碳循环
秦岭太白山南坡
soil organic carbon
soil moisture
altitudinal gradient effect
soil carbon cycle in mountainous ecosystems
southern slope of Taibai Mountain in the Qinling Mountains
