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林业科学 ›› 2025, Vol. 61 ›› Issue (7): 157-169.doi: 10.11707/j.1001-7488.LYKX20240646

• 研究论文 • 上一篇    下一篇

降水减少和间伐对日本落叶松人工林根系分布与生理特性的影响

冉馨1,孙晓梅1,吴春燕1,陈东升1,王宏星2,张守攻1,*()   

  1. 1. 林木遗传育种国家重点实验室 国家林业和草原局林木培育重点实验室 中国林业科学研究院林业研究所 北京 100091
    2. 吉林农业大学林学与草学学院 长春 130118
  • 收稿日期:2024-10-31 出版日期:2025-07-20 发布日期:2025-08-19
  • 通讯作者: 张守攻 E-mail:larchrif@163.com
  • 基金资助:
    “十四五”国家重点研发计划项目(2023YFD2200801)。

Effects of Precipitation Reduction and Thinning on the Root Distribution and Physiological Characteristics of Larix kaempferi

Xin Ran1,Xiaomei Sun1,Chunyan Wu1,Dongsheng Chen1,Hongxing Wang2,Shougong Zhang1,*()   

  1. 1. National Key Laboratory of Tree Genetics and Breeding Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration Research Institute of Forestry,Chinese Academy of Forestry Beijing 100091
    2. College of Forestry and Grassland Science, Jilin Agricultural University Changchun 130118
  • Received:2024-10-31 Online:2025-07-20 Published:2025-08-19
  • Contact: Shougong Zhang E-mail:larchrif@163.com

摘要:

目的: 设置培育措施与人工模拟气候变化的耦合试验,探讨间伐和降水减少双重影响下日本落叶松人工林土壤理化性质、根系分布与生理特性变化,为未来气候变化背景下落叶松人工林的合理经营提供科学依据。方法: 以辽宁省东部山区19年生日本落叶松人工林为研究对象,2019年4月设置对照(CKN)、未间伐+30%降水减少(CKR)、45%间伐强度+自然降水(T45N)、45%间伐强度+30%降水减少(T45R)4种处理,2023年7月分土层进行土壤和根系取样,测定土壤理化性质、根系分布与生理特性。结果: 1) 间伐和持续降水减少4年后,与对照相比,30%降水减少显著降低0~20 cm土层的土壤含水率、孔隙度、田间持水量,水解性氮、全氮、有效磷、全磷、速效钾和全钾含量,显著增加土壤密度;45%间伐强度和45%间伐强度+30%降水减少显著改善0~20 cm土层的土壤理化性质,间伐的正效应显著高于降水减少的负效应。2) 降水减少显著降低各土层不同水平距离的林木根系特征(根长密度、根表面积密度、根体积密度、根生物量密度),促进根系在20~60 cm土层和各土层水平100~200 cm的分布占比;间伐显著提高各土层水平距离的根系分布和生理特性。3) 主成分综合得分为T45N(1.54)>T45R(1.00)>CKN(–0.62)>CKR(–1.92),45%间伐强度和45%间伐强度+30%降水减少对土壤理化性质和根系特性具有正向影响,间伐可缓解降水减少对土壤理化性质以及根系分布与生理特性的负向影响。4) 相关性分析结果表明,根系呼吸和活力与根系分布、土壤含水率显著正相关,与土壤密度显著负相关。结论: 降水减少显著降低日本落叶松人工林土壤质量以及根系密度与生理活性,间伐显著提高土壤质量以及根系密度与生理活性,且间伐的正向影响显著高于降水减少的负向影响,合理间伐可作为应对未来气候变化背景下降水减少的有效营林措施之一。

关键词: 间伐, 降水减少, 日本落叶松人工林, 土壤性质, 根系分布, 生理特性

Abstract:

Objective: The effects of thinning and precipitation reduction on soil physical and chemical properties, root distribution and physiological characteristics of Japanese larch (Larix kaempferi) plantations were analyzed by developing a combined experiment of forest cultivation and artificial simulation of climate change, so as to provide scientific basis for the rational management of larch plantations under the background of future climate change. Method: In April 2019, four experimental treatments were conducted: control (CKN), no-thinning + 30% precipitation reduction (CKR), 45% thinning intensity + natural precipitation (T45N), and 45% thinning intensity+30% precipitation reduction (T45R) on a 19-year-old Japanese larch plantations located in the mountainous region of eastern Liaoning Province. In July 2023, soil and root samples were collected from different soil layers, and the soil physicochemical properties, root distribution, and root physiological characteristics were measured. Result: 1) Four years after the implementation of thinning and continuous precipitation reduction, compared to control, a 30% precipitation reduction significantly reduced soil moisture content, porosity, field capacity, hydrolyzed nitrogen, total nitrogen, available phosphorus, total phosphorus, available potassium, and total potassium in the 0–20 cm soil layer, while significantly increasing the soil bulk density. The 45% thinning intensity and 45% thinning intensity + 30% precipitation reduction significantly improved the physicochemical properties of the 0–20 cm soil layer, indicating that the positive effects of thinning were significantly greater than the negative effects of precipitation reduction. 2) Precipitation reduction significantly decreased root characteristics (root length density, surface area density, volume density, and biomass density) at different horizontal distances in each soil layer, and promoted root distribution in the 20–60 cm soil layer and at horizontal distance of 100–200 cm. Thinning significantly enhanced root distribution and physiological characteristics across soil layers and horizontal distances. 3) The comprehensive scores of principal components were as follows: T45N (1.54) > T45R (1.00) > CKN (–0.62) > CKR (–1.92), further demonstrating that 45% thinning intensity and 45% thinning intensity + 30% precipitation reduction had positive effects on soil physicochemical properties and root characteristics. Thinning mitigated the negative impact of precipitation reduction on soil physicochemical properties, root distribution, and physiological characteristics. 4) The correlation analysis results revealed that root respiration and vitality were significantly positively correlated with root distribution and soil water content, while significantly negatively correlated with soil bulk density. Conclusion: Precipitation reduction significantly deteriorates the soil quality, root density, and physiological activity of L. kaempferi plantations, whereas thinning notably improves these attributes. Moreover, the positive effects of thinning are significantly greater than the negative effects of precipitation reduction, indicating that appropriate thinning can be an effective management strategy to counteract the impacts of future climate change.

Key words: thinning, precipitation reduction, Larix kaempferi plantations, soil properties, root distribution, physiological characteristics

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