种内套种提升亚热带杉木人工林根际磷有效性：对可持续森林管理的启示

doi:10.1093/jpe/rtaf160

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种内套种提升亚热带杉木人工林根际磷有效性：对可持续森林管理的启示

收稿日期:2025-07-07 接受日期:2025-09-15

Intraspecific underplanting enhances rhizospheric phosphorus availability in subtropical Chinese fir plantations: Implications for sustainable forest management

Ming Li^1,2†, Pingping Lian^3†, Xinyu Zhang¹, Junjiao Ma¹, Yuhui Jiang¹, Yangyang Sun³, Shundan Chen¹, Xia Hu¹, Pengfei Wu^1,2, Shuisheng Fan^3*, Xiangqing Ma^1,2*

¹College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China

²Chinese Fir Engineering and Technological Research Center, National Forestry and Grassland Administration, Fuzhou 350002 , China

³College of JunCao Science and Ecology (College of Carbon Neutrality), Fujian Agriculture and Forestry University, Fuzhou 350002, China

^*Corresponding author. E-mail: shuisheng@fafu.edu.cn (S.F.); lxymxq@126.com (X.M.)

^†These authors contributed equally to this work.

Received:2025-07-07 Accepted:2025-09-15
Supported by:
This work was financially supported by the National Natural Science Foundation of China (Grant No. 32471906) and the First-Class Discipline Construction Funding of Forestry at Fujian Agriculture and Forestry University（725025030).

摘要/Abstract

摘要： 林下套种是一种传统的营林实践，优化的套种模式能增强植物对磷等限制性营养元素的获取。杉木（Cunninghamia lanceolata）广泛种植于亚热带贫磷土壤，杉木林下套种阔叶树被认为是提升土壤磷有效性的重要途径。然而，不同树种搭配如何通过特定的根际过程调控磷有效性的机制尚不明确。本研究以46年生杉木林为对象，分析了持续10年的四种林下套种模式（杉木种内套种, CF；套种木荷, CS；套种鹅掌楸, CL；套种木莲, CM）的根际磷循环机制。研究发现，CF处理的根际土壤有效磷、有机磷和全磷含量均显著高于三种阔叶树套种处理，且CF处理表现出最高的微生物生物量磷和碱性磷酸酶（ALP）活性。功能基因分析表明，CF处理中溶磷基因（ppx, pqqC, gcd）和矿化基因（phoD, phnK, phoX）的丰度更高。根系分泌物测定表明，CF处理分泌的草酸量高于CS和CL，且ALP活性更强，是有机磷矿化的主要驱动因素。本研究表明，杉木种内套种主要通过微生物驱动的有机磷矿化来提升根际磷有效性，而有机酸分泌则辅助活化了矿物态磷。杉木种内套种在最小化种间竞争的同时，维持了更高的微生物生物量和磷酸酶活性，而套种阔叶树处理中养分竞争降低了微生物效率。本研究提出，杉木种内套种作为一种可持续策略，可通过微生物驱动的有机磷矿化和有机酸介导的溶磷作用，缓解亚热带成熟人工林林下套种早期阶段的磷限制问题。

关键词: 磷活化, 根际微生物生物量, 酸性磷酸酶活性, 有机酸分泌, 种内套种

Abstract: Underplanting represents a traditional silvicultural practice, and optimal underplanting can enhance plant acquisition of limiting nutrients, especially phosphorus (P). Chinese fir (Cunninghamia lanceolata) is widely planted in low-latitude P-deficient regions. However, the beneficial companion species and species-specific rhizospheric mechanisms governing soil P availability in these systems remain poorly resolved. To address this, the study evaluated rhizospheric P cycling mechanisms in a 46-year-old plantation underplanted for 10 years with four treatments: autospecific Chinese fir (CF), Schima superba (CS), Liriodendron chinense (CL), and Manglietia fordiana (CM). After ten years, CF exhibited significantly higher available P (AP), organic P, and total P compared to broadleaf systems (CM, CS, CL), along with elevated microbial biomass P (MBP) and alkaline phosphatase (ALP) activity. Functional gene analysis reveals higher abundances of P-solubilizing (ppx, pqqC, gcd) and mineralizing (phoD, phnK, phoX) genes in CF. Root exudation profiles demonstrate that CF secreted more oxalic acid than CS and CL, and exhibited significantly higher ALP activity, which was a primary driver of organic P mineralization. These results highlight that intraspecific underplanting enhances rhizospheric P availability primarily through microbial-driven organic P mineralization, supported by organic acid-mediated solubilization of mineral-bound P. CF systems maintained higher microbial biomass and phosphatase activity while minimizing interspecific competition, unlike broadleaf treatments, where nutrient competition reduced microbial efficiency. This study proposes CF intraspecific underplanting as a sustainable strategy to alleviate P limitation during the early stages of underplantation in mature subtropical plantations via microbial-driven organic P mineralization and organic acid mediated solubilization, offering a sustainable strategy to alleviate P limitation in subtropical plantations.

Key words: Phosphorus mobilization, rhizosphere microbial biomass, acid phosphatase activity, organic acid secretion, intraspecific underplanting

. 种内套种提升亚热带杉木人工林根际磷有效性：对可持续森林管理的启示[J]. Journal of Plant Ecology, DOI: 10.1093/jpe/rtaf160.

Ming Li, Pingping Lian, Xinyu Zhang, Junjiao Ma, Yuhui Jiang, Yangyang Sun, Shundan Chen, Xia Hu, Pengfei Wu, Shuisheng Fan, Xiangqing Ma. Intraspecific underplanting enhances rhizospheric phosphorus availability in subtropical Chinese fir plantations: Implications for sustainable forest management[J]. J Plant Ecol, DOI: 10.1093/jpe/rtaf160.