植物生态学报 ›› 2021, Vol. 45 ›› Issue (2): 197-206.DOI: 10.17521/cjpe.2020.0263

• 研究论文 • 上一篇    下一篇

增温对南亚热带森林土壤磷形态的影响及其对有效磷的贡献

蒋芬1,2,3, 黄娟1,2, 褚国伟1,2, 程严1,2,3, 刘旭军1,2,3, 刘菊秀1,2, 列志旸1,2,3,*()   

  1. 1中国科学院华南植物园植被退化与生态系统管理重点实验室, 广州 510650
    2中国科学院核心植物园, 广州 510650
    3中国科学院大学, 北京 100049
  • 收稿日期:2020-08-03 接受日期:2020-12-12 出版日期:2021-02-20 发布日期:2021-03-09
  • 通讯作者: 列志旸
  • 作者简介:*(liezhiyang@scbg.ac.cn)
  • 基金资助:
    国家自然科学基金(41977287);国家自然科学基金(41991285);国家自然科学基金(31971459);广东省林业科技创新项目(2019KJCX023)

Effects of warming on soil phosphorus fractions and their contributions to available phosphorus in south subtropical forests

JIANG Fen1,2,3, HUANG Juan1,2, CHU Guo-Wei1,2, CHENG Yan1,2,3, LIU Xu-Jun1,2,3, LIU Ju-Xiu1,2, LIE Zhi-Yang1,2,3,*()   

  1. 1Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
    2Core Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
    3University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-08-03 Accepted:2020-12-12 Online:2021-02-20 Published:2021-03-09
  • Contact: LIE Zhi-Yang
  • Supported by:
    National Natural Science Foundation of China(41977287);National Natural Science Foundation of China(41991285);National Natural Science Foundation of China(31971459);Science and Technology Innovation Project of Guangdong Province Forestry(2019KJCX023)

摘要:

磷(P)是森林生态系统生产力的重要限制性元素。土壤磷的有效性取决于磷的存在形态及其转化过程。目前有关增温如何调控磷形态转化过程, 从而促进土壤有效磷含量增加的机制尚未明确。该研究以南亚热带森林为研究对象, 采用沿海拔高度从300 m下降至30 m以模拟温度自然上升的方法, 采集该林型0-10、10-20、20-40 cm的土壤, 并用适用于酸性土壤的连续浸提方法分离不同形态磷, 研究增温对土壤不同形态磷含量的影响, 探讨土壤不同形态磷与有效磷的关系, 识别对土壤有效磷在增温背景下增加有重要贡献的磷组分。结果表明增温使0-10 cm的无机钙磷(Ca-Pi)及20-40 cm的无机铁磷(Fe-Pi)和总无机磷含量分别显著增加了65.5%、17.9%和18.5%, 但对总有机磷及各有机磷组分含量均无显著影响。土壤不同形态磷与有效磷含量的相关分析表明, 有效磷与无机态的不同形态磷及有机铝磷、有机铁磷含量均显著正相关, 其中与Fe-Pi含量的相关性最强。通过土壤不同形态磷与有效磷含量的通径分析进一步发现, 无机铝磷、Fe-Pi是土壤磷转化过程中的重要中间过渡性磷组分, 且Fe-Pi是促进有效磷含量增加最重要的直接贡献磷组分。结合前期研究结果, 增温可能增大了凋落物磷对土壤磷的输入, 还可能强化了土壤的吸附和沉淀过程, 使得更多进入到土壤的溶解态磷转化为Ca-Pi、Fe-Pi等缓效磷源, 其中Fe-Pi可能成为南亚热带森林在气候变暖背景下最重要的有效磷来源。

关键词: 增温, 磷形态, 有效磷, 吸附-解吸附过程, 溶解-沉淀过程, 通径分析

Abstract:

Aims Phosphorus (P) is generally considered to be the important limiting element for forest ecosystem productivity. The availability of soil P depends on the existing fractions of P and their transformation processes. Many researches showed that warming increases soil available P concentration. However, it is still uncertain that how warming increases soil available P concentration through regulating the P cycle processes. The objective of this study was to investigate the effects of warming on concentration of different soil P fractions and to explore the relationships between different soil P fractions and available P concentration, thus identifying the important P fractions contributing to the increased available P concentration and its corresponding mechanisms under warming.
Methods A field warming experiment was conducted by translocating model forest ecosystems from 300 m to 30 m in south subtropical area. Soils with different treatments at 0-10, 10-20 and 20-40 cm depth were collected, respectively, and then different soil P fractions were separated by continuous extraction method applied in acid soils. The correlation analysis and path analysis were performed to explore the relationships between different soil P fractions and available P concentration in the soils.
Important findings The results showed that warming significantly increased the concentrations of inorganic P associated with calcium (Ca-Pi) at 0-10 cm depth and inorganic P concentration associated with iron (Fe-Pi) and total inorganic P concentration at 20-40 cm depth by 65.5%, 17.9% and 18.5%, respectively. However, it had no significant effects on total organic P and all organic P fractions. The correlation analysis results showed that available P concentration was significantly positively correlated with all inorganic P fractions and organic P associated with aluminum and iron. Furthermore, the correlation between available P and Fe-Pi concentration was the strongest. In addition, the path analysis highlights that inorganic P associated with aluminum and Fe-Pi were the important intermediate transitional P fractions in the conversion process of soil P, and Fe-Pi was the greatest direct contributor to the increased available P. Based on the results of previous studies, we propose that warming probably not only increased the input of plant litter P to soil P, but also strengthened desorption and dissolution processes, facilitating more dissolved P converted to moderately available P fractions including Fe-Pi and Ca-Pi. Furthermore, Fe-Pi may become the most important contributor of available P in south subtropical forests under warming.

Key words: warming, phosphorus fractions, available phosphorus, adsorption-desorption process, dissolution- precipitation process, path analysis