生态环境学报 ›› 2021, Vol. 30 ›› Issue (10): 1976-1989.DOI: 10.16258/j.cnki.1674-5906.2021.10.005

• 研究论文 • 上一篇    下一篇

典型城市森林旱季土壤团聚体稳定性与微生物胞外酶活性耦合关系

杨洪炳1,2(), 肖以华2,*(), 李明2, 许涵2, 史欣2, 郭晓敏1   

  1. 1.江西农业大学林学院,江西 南昌 330045
    2.中国林业科学研究院热带林业研究所,广东 广州 510520
  • 收稿日期:2021-08-04 出版日期:2021-10-18 发布日期:2021-12-21
  • 通讯作者: * 肖以华(1976年生),男,副研究员,主要从事城市化对森林土壤质量与碳中和潜力研究。E-mail: jxxiaoyihua@126.com
  • 作者简介:杨洪炳(1995年生),男,硕士研究生,研究方向为植被恢复与生态工程。E-mail: yhb1314@vip.qq.com
  • 基金资助:
    中国林科院基本科研业务专项(CAFYBB2018ZB001-7);广东林业生态定位监测网络平台建设项目(2020-KYXM-09);城乡梯度森林土壤微生物结构对重金属污染与植被耦合效应的响应机制(2021A1515010614);广州市林业与园林局“广州市城市森林生态系统效益监测、分析与研究”项目(穗财编[2019]105号)

Coupling Relationship between Soil Aggregate Stability and Microbial Extracellular Enzyme Activities in Typical Urban Forests during the Dry Season

YANG Hongbing1,2(), XIAO Yihua2,*(), LI Ming2, XU Han2, SHI Xin2, GUO Xiaomin1   

  1. 1. College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China
    2. Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China
  • Received:2021-08-04 Online:2021-10-18 Published:2021-12-21

摘要:

为了探究典型城市森林土壤团聚体稳定性旱季变化特征及影响因子,以广州市不同演替阶段的针叶林(Pine forest,PF)、针阔混交林(Mixed pine and broadleaf forest,MF)、常绿阔叶林(Broad-leaved evergreen forests,BF)为研究对象,分析表层土(0—10 cm)和剖面土(10—30 cm)团聚体稳定性、理化性质和微生物生物量及胞外酶活性等相关因子特征,以及土壤团聚体稳定性驱动因素与影响因素的耦合关系。结果表明,(1)土壤团聚体机械稳定性的平均重量直径(DMW)随土壤深度增加呈减小趋势,相反,几何平均直径(DGM)和重量分形维数(Dm)随土壤深度增加呈增大趋势。土壤团聚体水稳性的DMWDGM呈MF>BF>PF,而Dm变化与之相反。(2)土壤微生物酶活性易受磷限制,其受限制程度呈MF>BF>PF,与土壤团聚体水稳性在森林类型中变化规律一致。(3)土壤理化性质、微生物生物量、酶活性等因子对土壤团聚体机械稳定性整体空间差异解释程度为13.3%,而对土壤团聚体水稳性整体空间差异解释程度为40.0%。(4)土壤微生物熵和微生物胞外酶活性是土壤团聚体稳定性的主要驱动因子,水稳性主要受微生物生物量碳和酸性磷酸酶活性影响,而其机械稳定性主要受微生物生物量氮磷影响。(5)演替后期的针阔混交林和常绿阔叶林土壤表现出较高的碳利用效率及较低的氮利用效率,微生物可通过调控微生物生物量和调节碳氮元素利用效率来改善演替后期群落受磷限制状况,进而影响土壤团聚体稳定性。研究结果可为城市森林土壤质量评价和生态环境保护提供理论依据。

关键词: 城市森林土壤, 团聚体稳定性, 胞外酶活性, 结构方程模型, 元素利用效率

Abstract:

Pine forest (PF), mixed pine and broadleaf forest (MF), broad-leaved evergreen forests (BF), along successional stages of forest, were selected to explore the change of soil aggregates stability in typical urban forests in dry season. The distribution of soil aggregates, soil physical and chemical properties, microbial biomass and extracellular enzyme activity at topsoil (0-10 cm) and profile soil (10-30 cm) were analyzed. Furthermore, the coupling relationships between soil enzyme activities and soil aggregates were also linked. The results showed that: (1) the mean weight diameter (DMW) of soil agglomerate mechanical stability decreased with increasing soil depth. However, the geometric mean diameter (DGM) and weight fractal dimension (Dm) increased with soil depth. The DMW and DGM of soil agglomerates of water stability showed in MF>BF>PF, while Dm varied oppositely. (2) Soil microbial enzyme activity was sensitive to phosphorus limitation, and the rule of limitation in successional forests was MF>BF>PF, which was according to the regular pattern of soil aggregate water stability. (3) Soil physicochemical properties, microbial biomass, enzyme activity explained the 13.3% of overall spatial variation of soil agglomerate mechanical stability, while the overall spatial variation of soil agglomerate water stability was 40.0%. (4) Soil microbial entropy and extracellular enzyme activity were the main driving factors to soil agglomerate stability. Water stability was mainly affected by microbial biomass carbon and acid phosphatase activity, while its mechanical stability was mainly affected by microbial biomass nitrogen and phosphorus. (5) The soil of MF and BF, had higher carbon use efficiency and lower nitrogen use efficiency. Microorganisms can improve the phosphorus limitation in MF and BF by regulating microbial biomass and carbon and nitrogen use efficiency, and then affect the stabilities of soil aggregate. These findings have important scientific significances for urban forest soil management and urban environmental protection.

Key words: urban forest soil, agglomerate stability, extracellular enzyme activity, structural equation modelling, elemental use efficiency

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