Ecology and Environmental Sciences ›› 2025, Vol. 34 ›› Issue (9): 1386-1397.DOI: 10.16258/j.cnki.1674-5906.2025.09.006

• Papers on Carbon Cycling and Carbon Emission Reduction • Previous Articles     Next Articles

Spatio-temporal Characteristics of Soil Organic Carbon and Its Components in Typical tea Gardens in Hunan Province, China

LIU Qing1,2,3(), GONG Yushun4, WANG Wei1,*(), FANG Xiantao2,3, WU Jinshui2,3, SHEN Jianlin2,3,*()   

  1. 1. Resources and Environment College of Tibet Agriculture and Animal Husbandry College, Linzhi 860000, P. R. China
    2. Institute of Subtropical Agricultural Ecology, Chinese Academy of Sciences/Key Laboratory of Subtropical Agricultural Ecological Process, Changsha 410125 P. R. China
    3. Subtropical Agricultural Ecology Institute, Chinese Academy of Sciences/Changsha Agricultural Environment Observation and Research Station, Changsha 410125 P. R. China
    4. Key Laboratory of Tea Science of Ministry of Education/Hunan Agricultural University, Changsha 410128, P. R. China
  • Received:2025-01-09 Online:2025-09-18 Published:2025-09-05

湖南典型茶园土壤有机碳及其组分时空特征

刘卿1,2,3(), 龚雨顺4, 王伟1,*(), 方贤滔2,3, 吴金水2,3, 沈健林2,3,*()   

  1. 1.西藏农牧学院资源与环境学院,西藏 林芝 860000
    2.中国科学院亚热带农业生态研究所/亚热带农业生态过程重点实验室,湖南 长沙 410125
    3.中国科学院亚热带农业生态研究所/长沙农业环境观测研究站,湖南 长沙 410125
    4.湖南农业大学/茶学教育部重点实验室,湖南 长沙 410128
  • 通讯作者: *沈健林。E-mail: jlshen@isa.ac.cn;王伟。Email: xzwangwei@xza.edu.cn
  • 作者简介:刘卿(1999年生),女,硕士研究生,研究方向为土壤碳循环。E-mail: 2111972814@qq.com
  • 基金资助:
    国家自然科学基金国际项目(42161144002);国家自然科学基金国际项目(U23A2009);中国科学院青年创新促进会优秀会员项目(Y2021102)

Abstract:

Soil organic carbon pool is the largest carbon pool in terrestrial ecosystems. The quantity and quality of the soil organic carbon (SOC) pool determines the soil fertility status; thus, it is an important indicator for assessing soil quality. Tea plantations are one of the most important land use types in China, and the study of the composition and spatio-temporal variations of soil organic carbon pools in tea plantations is of great significance for accurately assessing regional carbon sinks. In this study, 12 typical tea-planting areas in Hunan Province, located in the subtropical zone, were selected as research subjects. Soil samples were collected from tea gardens with different planting years (0‒5 years, 10‒15 years, and over 20 years) in each area. The effects of planting year, soil depth, and tea ridge/row distribution on the content and composition characteristics of soil organic carbon in tea gardens were studied to provide a scientific basis for carbon sink assessment and fertility improvement in tea garden soils. The results showed that in typical tea gardens in Hunan Province, soil organic carbon contents in the 0‒20 cm and 20‒40 cm soil layers were 11‒48.88 g·kg−1 and 1.79‒33.08 g·kg−1, respectively. Soil organic carbon content showed an increasing trend with increasing planting years. The average soil organic carbon contents were 11.12 g·kg−1, 12.89 g·kg−1, and 17.91 g·kg−1 in the 0‒40 cm soil layer with 0‒5 years, 10‒15 years, and over 20 years of planting, respectively. Soil organic carbon content of the tea ridges was significantly lower than that of the tea rows. The average soil organic carbon content in the 0-40 cm soil layer of tea rows were1.37 times that of the tea ridges. The dissolved organic carbon, microbial biomass carbon, particulate organic carbon, and mineral-associated organic carbon content in tea garden soil accounted for 1.21%, 1.31%, 25.71%, and 41.59% of soil organic carbon, respectively. The spatial and temporal variations of soil organic carbon components in tea plantations showed that with the increase in planting years, the content of soil organic carbon components increased, but the proportion of mineral-associated carbon in soil organic carbon decreased in tea gardens for more than 20 years, and the content of soil organic carbon components in tea rows was significantly higher than that in tea ridges. Random forest analysis showed that attitude was the most critical factor affecting the SOC content in tea gardens in Hunan Province. We estimated that the soil organic carbon storage reached 18.6×10⁶ t in the 0‒40 cm soil layer of tea gardens in Hunan Province. In summary, with increase soil depth, the content of soil organic carbon and its components in tea gardens decreased. The increase in planting years was beneficial to the accumulation of soil organic carbon and its components in tea gardens, which had the potential to act as carbon sinks.

Key words: tea-planting years, soil depth, tea garden, soil organic carbon, components of organic carbon

摘要: 土壤有机碳库是陆地生态系统中最大的碳库,其数量和质量决定土壤肥力状况,是评估土壤质量的重要指标。茶园是中国重要的土地利用类型,研究其土壤有机碳库组成与时空变化特征对精准评估区域碳汇具有重要意义。以位于亚热带区的湖南省12个典型植茶区为研究对象,采集不同种植年限(0-5、10-15、20年以上)茶园土壤,研究种植年限、土层深度、茶垄/茶行分布对茶园土壤有机碳质量分数及组成特征,以期为茶园土壤碳汇评估和茶园培肥提供科学依据。结果表明,湖南典型茶园在0-20 cm和20-40 cm土层土壤有机碳(SOC)质量分数分别为11-48.88 g·kg−1和1.79-33.08 g·kg−1,随种植年限的增加,土壤有机碳呈上升趋势,在0-5年茶园、10-15年茶园和20年以上茶园0-40 cm土层土壤有机碳平均质量分数分别为11.12、12.89、17.91 g·kg−1。茶垄土壤有机碳质量分数显著低于茶行,茶行0-40 cm土层土壤有机碳平均质量分数是茶垄的1.37倍。茶园土壤可溶性有机碳、微生物量碳、颗粒有机碳和矿物结合态质量分数分别占到土壤有机碳的1.21%、1.31%、25.71%和41.59%,各土壤有机碳组分的时空变化特征为随着种植年限的延长,土壤有机碳组分质量分数增加,但矿物结合态有机碳占土壤有机碳比例到20年以上茶园开始降低,茶行土壤有机碳组分质量分数显著高于茶垄。随机森林分析显示影响区域茶园土壤有机碳及其组分质量分数的因子中最关键的因子是海拔,估算得到湖南省茶园表层0-40 cm土壤有机碳储量达18.6×106 t。综上,随土层深度的增加,茶园土壤有机碳及其组分质量分数减少,植茶年限的增加有利于茶园土壤有机碳及其组分质量分数的累积,茶园具有一定的碳汇功能。

关键词: 植茶年限, 土层深度, 茶园, 土壤有机碳, 有机碳组分

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