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林业科学 ›› 2025, Vol. 61 ›› Issue (6): 75-84.doi: 10.11707/j.1001-7488.LYKX20240089

• 研究论文 • 上一篇    下一篇

马尾松人工林土壤有机碳及其组分对林龄的响应及驱动因素

胡建文1,2,刘常富1,3,4,*(),勾蒙蒙1,3,4,雷蕾1,3,4,陈会玲1,张佳佳1,朱粟锋1,斛如媛1,肖文发1,3,4   

  1. 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. 山西大同大学煤基生态碳汇技术教育部工程研究中心 大同 037009
    3. 南京林业大学南方现代林业协同创新中心 南京 210037
    4. 湖北秭归三峡库区森林生态系统国家定位观测研究站 秭归 443600
  • 收稿日期:2024-02-14 出版日期:2025-06-10 发布日期:2025-06-26
  • 通讯作者: 刘常富 E-mail:liucf898@163.com
  • 基金资助:
    中央级公益性科研院所基本科研业务费专项资金(CAFYBB2022XD002);国家自然科学基金重大项目课题(32192434)。

Response and Driving Factors of Soil Organic Carbon and Its Fractions to Stand Age in Pinus massoniana Plantation

Jianwen Hu1,2,Changfu Liu1,3,4,*(),Mengmeng Gou1,3,4,Lei Lei1,3,4,Huiling Chen1,Jiajia Zhang1,Sufeng Zhu1,Ruyuan Hu1,Wenfa Xiao1,3,4   

  1. 1. Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation Institute, CAF Beijing 100091
    2. Engineering Research Center of Coal-Based Ecological Carbon Sequestration Technology of the Ministry of Education Shanxi Datong University Datong 037009
    3. Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University Nanjing 210037
    4. Three Gorges Reservoir National Forest Ecosystem Observation and Research Station, Zigui, Hubei Province Zigui 443600
  • Received:2024-02-14 Online:2025-06-10 Published:2025-06-26
  • Contact: Changfu Liu E-mail:liucf898@163.com

摘要:

目的: 分析不同林龄马尾松人工林土壤有机碳(SOC)及其组分碳库变化特征和影响因素,为厘清人工林SOC固存机制提供参考。方法: 以亚热带马尾松人工幼龄林(6 a)、中龄林(13 a)、近熟林(29 a)、成熟林(38 a)和过熟林(57 a)为对象,探索0~10 cm土层SOC及其组分的林龄梯度规律,分析SOC组分变化与林木特征、土壤化学性质和微生物生物量等指标的关系,探讨人工林SOC固存机制。结果: SOC含量在成熟林[(21.90±1.07) g·kg?1]显著(P<0.05)高于幼龄林[(15.35±0.37) g·kg?1]和中龄林[(13.22±0.83)g·kg?1]。成熟林矿物结合组分的干质量分数(72.98%)显著(P<0.05)低于幼龄林、中龄林、近熟林和过熟林,而轻颗粒组分的干质量分数(26.08%)和重颗粒组分的干质量分数(0.93%)显著(P<0.05)高于幼龄林和中龄林(P<0.05)。成熟林矿物结合组分有机碳含量[(21.90±1.07) g·kg?1]显著(P<0.05)高于幼龄林、中龄林、近熟林和过熟林,重颗粒组分有机碳含量[(21.00±1.76)g·kg?1]显著(P<0.05)低于过熟林[(55.81±9.89 g·kg?1],轻颗粒组分有机碳含量[(286.99±3.69)g·kg?1]显著(P<0.05)低于中龄林[(335.68±12.45) g·kg?1]。所有龄组矿物结合组分有机碳质量分数均大于50%,主导SOC积累。成熟林矿物结合组分有机碳质量分数(66.78%)显著(P<0.05)低于幼龄林、中龄林、近熟林和过熟林。相关性分析显示,SOC含量与轻颗粒组分的干质量分数、重颗粒组分的干质量分数和矿物结合组分有机碳含量显著(P<0.05)正相关,与轻颗粒组分有机碳含量显著(P<0.05)负相关。逐步回归分析显示,地表凋落物、轻颗粒组分的干质量分数、重颗粒组分的干质量分数和矿物结合组分有机碳含量驱动SOC积累(R2=0.98)。偏最小二乘模型显示,林分发育过程中矿物结合组分(包含矿物结合组分有机碳含量和碳磷比)对SOC积累总效应最高(0.91)。结论: 马尾松人工林林分发育过程中矿物结合有机碳主导SOC积累,且成熟林SOC的高效固存受地表凋落物和SOC组分的共同调控。

关键词: 马尾松人工林, 土壤有机碳, 土壤有机碳组分, 林龄

Abstract:

Objective: Analyzing the variation characteristics and influencing factors of soil organic carbon (SOC) and its fraction carbon pools in Pinus massoniana plantations of different stand ages, to provide a reference for clarifying the SOC sequestration mechanisms in plantations. Method: This study investigated subtropical P. massoniana plantations across stand age classes: young (6 a), middle-aged (13 a), near-mature (29 a), mature (38 a), and over-mature (57 a). Explored age-dependent patterns of SOC and its fractions in the 0–10 cm soil layer, analyzed relationships between SOC fraction dynamics and key indicators (tree characteristics, soil chemical properties, and microbial biomass), and further discussed the underlying mechanisms of SOC sequestration in plantation ecosystems. Result: The SOC content in mature plantation was significantly higher than that in young plantation and middle-aged plantation. The dry mass fraction of mineral-associated fraction (72.98%) in mature plantation was significantly lower than young plantation, middle-aged plantation, near-mature plantation and over-mature plantation (92.67%–93.33%), while the dry mass fraction of light particle fraction (26.08%) and heavy particle fraction (0.93%) were significantly higher than young and middle-aged plantations. The organic carbon content of mineral-associated fraction in mature plantation was significantly higher than young, middle-aged, near-mature, and over-mature plantations, the organic carbon content of heavy particulate fraction was significantly lower than that in over-mature plantation, and the organic carbon content of light particulate fraction was significantly lower than middle-aged plantation. The organic carbon mass fraction of mineral-associated fraction in all age groups was > 50%, which dominated the accumulation of SOC. The organic carbon dry mass fraction of mineral-associated fraction in mature plantation (66.78%) was significantly lower than young, middle-aged, near-mature and over-mature plantations. Correlation analysis revealed that SOC content was significantly positively correlated with the dry mass fraction of light particle fraction, the dry mass fraction of heavy particle fraction and the mineral-associated fraction organic carbon content, and was significantly negatively correlated with the light particle fraction organic carbon content. Stepwise regression analysis showed that SOC accumulation was driven by forest floor litter, dry mass fraction of light particle fraction, dry mass fraction of heavy particle fraction and mineral-associated fraction organic carbon content (R2=0.98). The partial least squares model showed that the total effect of mineral-associated fraction (including organic carbon content and carbon-phosphorus ratio of mineral‐associated fraction) on SOC accumulation was the highest (0.91) during stand development. Conclusion: The mineral-associated protection mechanisms mediate the dynamics of soil organic carbon sequestration during stand development in P. massoniana plantations. In the mature plantation, synergistic effects between forest floor litter and SOC fractions facilitated highly efficient SOC sequestration.

Key words: Pinus massoniana plantation, soil organic carbon, soil organic carbon fraction, stand age

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