树种与城市绿地类型通过微生物-酶途径共同驱动根际土壤有机碳组分与稳定性

doi:10.1093/jpe/rtaf224

Journal of Plant Ecology

树种与城市绿地类型通过微生物-酶途径共同驱动根际土壤有机碳组分与稳定性

收稿日期:2025-09-02 接受日期:2025-11-26

Tree species and urban green space types jointly drive rhizosphere SOC fractionation and stability via microbial-enzymatic pathways

Yushu Tian¹, Pin Li^1*, Chenhan Ma¹, Yun Li¹, Qiannan Lin¹, Xiaofan Hou¹, Xilin Yuan¹, Xiaotong Zhu¹, Congcong Shen^2*

¹State Key Laboratory of Efficient Production of Forest Resources, The Key Laboratory for Silviculture and Conservation of Ministry of Education, Key Laboratory for Silviculture and Forest Ecosystem of State Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China

²State Key Laboratory of Regional and Urban Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China

^*Corresponding author: Pin Li

Received:2025-09-02 Accepted:2025-11-26
Supported by:
This work was supported by the National Natural Science Foundation of China (32271673), and 5·5 Engineering Research & Innovation Team Project of Beijing Forestry University (No: BLRC2023B06). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

摘要/Abstract

摘要： 城市土壤有机碳(SOC)动态受植物—微生物相互作用的复杂调控，但树木功能类型与绿地管理对根际SOC组分与稳定性的协同效应尚不明确。本研究揭示了2种本地树种——毛白杨(Populus tomentosa)与油松(Pinus tabuliformis)——在四种城市绿地类型(城市公园、居住区、道路防护林、城郊森林)中调控SOC稳定的不同机制。通过整合胞外酶化学计量、微生物群落装配与SOC组分分离分析，我们发现碳(C)与磷(P)有效性是城市土壤微生物代谢的主要限制因子。毛白杨根际SOC含量(在居住区最高可达77.0%)与稳定性(MAOC/SOC比值在道路防护林最高达73%)均显著高于油松，这主要受真菌主导的C/P限制以及更高的水解酶活性(β-1,4-葡萄糖苷酶、β-1,4-N-乙酰氨基葡萄糖苷酶和碱性磷酸酶；高出1.3−2.1倍)驱动。相反，油松倾向于氧化酶活性(酚氧化酶高出13%)，导致SOC积累较少，尽管其在城郊森林中的稳定性较高(MAOC/SOC比值为63%)。关键的是，绿地类型调节了这一权衡关系：高强度管理(如城市公园)通过养分富集提升了SOC绝对储量，而低干扰地点(如城郊森林)则通过微生物生态位分化提高了稳定效率(MAOC/SOC)。本研究提出了一个将树种功能性状、微生物代谢限制与酶活权衡与SOC动态相联系的机理框架，为优化城市绿地碳汇功能提供了基于科学的规划设计策略。

关键词: 城市土壤固碳, 酶化学计量, 微生物群落装配, 土壤有机碳组分, 根际微生物组, 绿色基础设施, 养分限制

Abstract: Urban soil organic carbon (SOC) dynamics are governed by complex vegetation-microbe interactions, but the synergistic effects of tree functional types and green space management on rhizosphere SOC fractionation and stability remain unclear. This study elucidates the distinct mechanisms by which two native tree species—Populus tomentosa (deciduous broadleaf) and Pinus tabuliformis (evergreen conifer)—regulate SOC stabilization across four urban green space types (urban parks, residential areas, roadside shelterbelts, and suburban forests). Combining extracellular enzyme stoichiometry, microbial community assembly, and SOC fractionation analyses, we demonstrate that carbon (C) and phosphorus (P) availability are the primary constraints on microbial metabolism in urban soils. P. tomentosa rhizospheres exhibited significantly higher SOC content (up to 77.0% in residential areas) and stability (MAOC/SOC ratio, peaking at 73% in roadside shelterbelts) than P. tabuliformis, driven by fungal-dominated C/P limitation and elevated hydrolytic enzyme activity (β-1,4-glucosidas, β-1,4-N-acetylglucosaminidase, and alkaline phosphatase; 1.3-2.1-fold higher). In contrast, P. tabuliformis favored oxidative enzyme activity (13% greater phenol oxidase), leading to diminished SOC accumulation despite greater stability in suburban forests (63% MAOC/SOC ratio). Critically, green space type mediated this trade-off: intensive management (e.g. urban parks) boosted absolute SOC storage via nutrient enrichment, whereas low-disturbance sites (e.g. suburban forests) enhanced stabilization efficiency (MAOC/SOC) through microbial niche partitioning. Our results provide a novel mechanistic framework linking tree functional traits, microbial metabolic constraints, and enzymatic trade-offs to SOC dynamics, offering science-based strategies for urban green space design to optimize carbon sequestration.

Key words: urban soil carbon sequestration, enzyme stoichiometry, microbial community assembly, SOC fractionation, rhizosphere microbiome, green infrastructure, nutrient limitation

. 树种与城市绿地类型通过微生物-酶途径共同驱动根际土壤有机碳组分与稳定性[J]. Journal of Plant Ecology, DOI: 10.1093/jpe/rtaf224.

Yushu Tian, Pin Li, Chenhan Ma, Yun Li, Qiannan Lin, Xiaofan Hou , Xilin Yuan, Xiaotong Zhu, Congcong Shen. Tree species and urban green space types jointly drive rhizosphere SOC fractionation and stability via microbial-enzymatic pathways[J]. J Plant Ecol, DOI: 10.1093/jpe/rtaf224.

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