神农架林区天然次生林土壤有机碳分布及影响因素  

Distribution and influencing factors of soil organic carbon in natural secondary forests of Shennongjia Forestry District

作　　者：樊子豪 崔鸿侠[2,3] 沈琛琛 陈吉臻[1] 肖文发 刘常富[1,4] 黄志霖 FAN Zihao;CUI Hongxia;SHEN Chenchen;CHEN Jizhen;XIAO Wenfa;LIU Changfu;HUANG Zhilin(Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation Institute,Chinese Academy of Forestry,Beijing 100091,China;Hubei Academy of Forest,Wuhan 430075,China;Hubei Shennongjia Forestry Ecosysten Research Station,Shennongjia 442421,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]中国林业科学研究院森林生态环境与自然保护研究所,国家林业和草原局森林生态环境重点实验室,北京100091 [2]湖北省林业科学研究院,武汉430075 [3]湖北神农架森林生态系统国家定位观测研究站,神农架442421 [4]南京林业大学南方现代林业协同创新中心,南京210037

出　　处：《生态学报》2024年第16期7130-7139,共10页Acta Ecologica Sinica

基　　金：神农架国家公园本底资源综合调查研究项目(SNJNP2023010);神农架金丝猴保育生物学湖北省重点实验室开放课题基金(SNJGKL2023010)。

摘　　要：神农架林区气候、土壤类型和森林具有明显海拔梯度分布特征,且存在大量植被组成丰富、林分结构复杂的天然次生林。以天然次生林为研究对象,通过系统样地调查、逐步回归和结构方程模型(SEM)揭示天然次生林土壤有机碳分布特征,探索土壤有机碳含量与气候、海拔、土壤和林分结构之间的多变量关系。研究结果表明:在1200—2500 m海拔区间,土壤有机碳含量随海拔升高而增加,土壤有机碳平均含量表现为17.45 g/kg(1200—1600 m)<21.56 g/kg(1600—2000 m)<27.37 g/kg(2000—2500 m)。在0—20 cm、20—40 cm和40—60 cm深度土层土壤有机碳随土层加深而逐步降低,平均含量分别为30.5 g/kg、21.7 g/kg和13.73 g/kg,且各土层之间差异显著(P<0.05);海拔、土壤密度、pH和树种多样性(TSD)在各土层与土壤有机碳含量存在显著相关性。海拔梯度变化通过影响土壤密度和pH间接影响土壤有机碳含量,在各土层具有一致性;20—40 cm、40—60 cm土层,树种多样性变化影响土壤密度间提升进土壤有机碳含量。树种多样性对土壤有机碳含量的正向影响强烈依赖于土壤深度,深层(40—60 cm)土壤有机碳含量对树种多样性更为敏感。天然次生林维持较高的树种多样性有助于提升森林土壤碳汇能力,本研究结果为亚热带天然次生林的森林经营与生态管理提供理论依据。The Shennongjia Forestry District has been widely concerned with species diversity,with a large number of natural forests of rich species types and significant differences in vegetation types along the altitudinal gradient.This study focused on understanding the distribution characteristics of soil organic carbon content in natural secondary forests in the Shennongjia Forestry District.Using stepwise regression and structural equation modeling(SEM),we explored the multivariate relationships between soil organic carbon content and climate,elevation,soil properties,and stand structure.The soil organic carbon content was closely related to altitude,with significantly higher content at high altitudes compared to low altitudes.The average soil organic carbon content in the three altitudinal ranges was 27.37 g/kg(2000—2500 m),21.56 g/kg(1600—2000 m),and 17.45 g/kg(1200—1600 m),respectively.The soil organic carbon content in the 0—20 cm,20—40 cm,and 40—60 cm soil layers was 30.5 g/kg,21.7 g/kg,and 13.73 g/kg,respectively.The contents decreased gradually with increasing soil depth,and there were significant differences among different soil layers(P<0.05).Altitude,soil bulk,pH,and tree species diversity all showed a strong linear relationship with soil organic carbon content in all soil layers.Altitude indirectly affected soil organic carbon content by regulating soil bulk and pH,and this relationship remained consistent across all soil layers.The tree species diversity in the 20—40 cm and 40—60 cm soil layers indirectly contributed to soil organic carbon content by regulating soil bulk.The positive effect of tree species diversity on soil organic carbon content was strongly dependent on soil depth,especially in the deep soil layer(40—60 cm).Maintaining high tree species diversity can promote the carbon sink capacity of forest soils.

关 键 词：土壤有机碳含量 天然次生林 分布特征 树种多样性 神农架林区 

分 类 号：S714.2[农业科学—林学]