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  

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

作　　者：蒋芬 黄娟[1,2] 褚国伟[1,2] 程严[1,2,3] 刘旭军 刘菊秀 列志旸 JIANG Fen;HUANG Juan;CHU Guo-Wei;CHENG Yan;LIU Xu-Jun;LIU Ju-Xiu;LIE Zhi-Yang(Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;Core Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[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

出　　处：《植物生态学报》2021年第2期197-206,共10页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(41977287、41991285和31971459);广东省林业科技创新项目(2019KJCX023);广州市民生科技攻关项目(201903010021)的资助。

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0–10cm的无机钙磷(Ca-Pi)及20–40cm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。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-

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 

分 类 号：S714.2[农业科学—林学]