南京林业大学学报(自然科学版) ›› 2023, Vol. 47 ›› Issue (6): 77-84.doi: 10.12302/j.issn.1000-2006.202204052

所属专题: 山水林田湖草一体化保护和生态修复——土壤侵蚀修复研究

• 专题报道Ⅱ:山水林田湖草一体化保护和生态修复——土壤侵蚀修复研究(执行主编 张金池) • 上一篇    下一篇

水蚀作用下红壤丘陵区土壤特性的空间分异特征

张相1(), 丁鸣鸣2, 林杰1,*(), 李卓远1, 崔琳琳1, 郭赓1, 杨皓1   

  1. 1.南京林业大学林草学院、水土保护学院,南方现代林业协同创新中心,江苏省水土保持与生态修复重点实验室,江苏 南京 210037
    2.南京市水务局,江苏 南京 210036
  • 收稿日期:2022-04-21 修回日期:2022-06-17 出版日期:2023-11-30 发布日期:2023-11-23
  • 通讯作者: *林杰(jielin@njfu.edu.cn),教授。
  • 基金资助:
    国家自然科学基金面上项目(31870600)

Spatial differentiation of soil properties in hilly red soil region under water erosion

ZHANG Xiang1(), DING Mingming2, LIN Jie1,*(), LI Zhuoyuan1, CUI Linlin1, GUO Geng1, YANG Hao1   

  1. 1. College of Forestry and Grassland, College of Soil and Water Conservation, Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University, Nanjing 210037,China
    2. Nanjing Water Affairs Bureau, Nanjing 210036,China
  • Received:2022-04-21 Revised:2022-06-17 Online:2023-11-30 Published:2023-11-23

摘要:

【目的】揭示由水蚀引起的土壤质量变异的规律,为南方红壤丘陵区水土流失防治及低效林改造提供科学性的数据支撑。【方法】选取江西省吉安市青原山小流域作为南方红壤丘陵区的典型区,按照典型性和代表性将小流域划分坡位,对各坡位土壤团聚体组成进行分析,并应用相关性分析探究水蚀过程中各指标间的影响关系。【结果】水力侵蚀改变了土壤容重和土壤孔隙的空间分布格局,致使侵蚀区的土壤抗蚀性变弱,沉积区影响不大,加速了土壤侵蚀的发生。长期侵蚀后土壤容重增大,与其他坡位相比,坡脚处土壤容重显著增加了0.16 g/cm3(P<0.05),而饱和持水量和毛管孔隙度均表现为显著减小(P<0.05);水蚀后,土壤质地的组成也发生了变化,土壤砂粒含量显著增加,黏粒和粉粒含量显著减小(P<0.05)。水蚀过程对不同坡位的土壤养分影响不一,侵蚀后坡上、坡中和坡下土壤全氮、速效磷、有机碳含量和碳氮比降低,坡上各养分含量显著降低(P<0.05);与侵蚀前相比,侵蚀后坡脚处的养分含量均增加,速效磷显著增加了39.31%(P<0.05)。水蚀后不同坡位的水稳性团聚体质量分数(R0.25)、平均质量直径(MWD)和几何平均直径(GMD)均呈现降低的变化,坡脚处的变化不明显,土壤结构稳定性最高。【结论】南方红壤丘陵区生态系统脆弱,长期水蚀作用可使红壤的团聚体稳定性降低,水蚀过程使侵蚀-沉积部位的土壤理化性质发生了空间分异,植被覆盖度和枯落物厚度是主要的环境影响因素。

关键词: 土壤侵蚀, 水蚀作用, 理化性质, 团聚体, 空间分异, 南方红壤丘陵区

Abstract:

【Objective】This study aims to reveale the law of soil quality variation caused by water erosion provides scientific data support for soil erosion control and low-efficiency forest transformation in hilly red soil region of southern china.【Method】The small watershed of Qingyuan Mountain in Ji ’an City, Jiangxi Province was selected as a typical area of red soil hilly area in southern China. According to the typicality and representativeness, the small watershed was divided into slope positions, and three sections were set up to collect soil repeatedly. The composition of soil aggregates was analyzed, and the correlation analysis was used to explore the relationship between various indicators in the process of water erosion.【Result】Water erosion changed the spatial distribution pattern of bulk density and soil porosity, resulting in weaker soil anti-erodibility in erosion area and less influence in deposition area, which accelerated the occurrence of soil erosion. Soil bulk density increased after long-term erosion. Compared with other slope positions, soil bulk density at slope toe increased significantly by 0.16 g/cm3 (P < 0.05), while saturated water holding capacity and capillary porosity decreased significantly (P < 0.05). After water erosion, the composition of soil texture also changed, soil sand content increased significantly, clay and silt content decreased significantly (P < 0.05). The water erosion process had different effects on soil nutrients at different slope positions. The soil total nitrogen, available phosphorus, organic carbon content and carbon-nitrogen ratio decreased on the upper, middle and lower slopes, and the content on the slope decreased significantly (P < 0.05). Compared with other slope positions, the nutrient content at the toe of the slope increased, and the available phosphorus increased significantly by 39.31% (P < 0.05). After water erosion, the mass fraction (R0.25), mean mass diameter (MWD) and geometric mean diameter (GMD) of water-stable aggregates at different slope positions showed a decreasing trend, and the change at the foot of the slope was not obvious, and the stability of soil structure was the highest.【Conclusion】The ecosystem of red soil hilly area in southern China is fragile. Long-term water erosion can reduce the stability of red soil aggregates. The water erosion process causes spatial differentiation of soil physical and chemical properties in erosion-deposition sites. Vegetation coverage and litter thickness are the main environmental factors.

Key words: soil erosion, water erosion, physicochemical properties, aggregates, spatial differentiation, red soil hilly area in southern China

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