J Plant Ecol ›› 2023, Vol. 16 ›› Issue (4): rtac093.DOI: 10.1093/jpe/rtac093

• Research Articles •    

Divergent leaf nutrient-use strategies of coexistent evergreen and deciduous trees in a subtropical forest

Xiaoping Chen1,2,3,4, Xingui Le5, Karl J. Niklas6, Dandan Hu2,3,4, Quanlin Zhong2,3,4, Dongliang Cheng2,3,4,*   

  1. 1College of Tourism and Resources Environment, Zaozhuang University, Zaozhuang 277160, China;
    2Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China;
    3Key Laboratory of Humid Subtropical Eco-geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China;
    4Fujian Provincial Key Laboratory of Plant Ecophysiology, College of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China;
    5Yangjifeng National Nature Reserve Administration, Yingtan, China, 6Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca 14850, NY, USA
  • Received:2022-05-22 Revised:2022-07-08 Accepted:2022-10-07 Online:2022-10-21 Published:2023-08-01
  • Contact: E-mail: chengdl02@aliyun.com

基于不同养分策略的亚热带常绿与落叶树种的共存机制

Abstract: Evergreen and deciduous species coexist in the subtropical forests in southeastern China. It has been suggested that phosphorus (P) is the main limiting nutrient in subtropical forests, and that evergreen and deciduous species adopt different carbon capture strategies to deal with this limitation. However, these hypotheses have not been examined empirically to a sufficient degree. In order to fill this knowledge gap, we measured leaf photosynthetic and respiration rates, and nutrient traits related to P-, nitrogen (N)- and carbon (C)-use efficiencies and resorption using 75 woody species (44 evergreen and 31 deciduous species) sampled in a subtropical forest. The photosynthetic N-use efficiency (PNUE), respiration rate per unit N and P (Rd,N and Rd,P, respectively) of the deciduous species were all significantly higher than those of evergreen species, but not in the case of photosynthetic P-use efficiency. These results indicate that, for any given leaf P, evergreen species manifest higher carbon-use efficiency (CUE) than deciduous species, a speculation that is empirically confirmed. In addition, no significant differences were observed between deciduous and evergreen species for nitrogen resorption efficiency, phosphorus resorption efficiency or N:P ratios. These results indicate that evergreen species coexist with deciduous species and maintain dominance in P-limited subtropical forests by maintaining CUE. Our results also indicate that it is important to compare the PNUE of deciduous species with evergreen species in other biomes. These observations provide insights into modeling community dynamics in subtropical forests, particularly in light of future climate change.

Key words: photosynthetic nutrient-use efficiency, carbon-use efficiency, nitrogen resorption efficiency, phosphorus resorption efficiency, species coexistence

摘要:
常绿和落叶树种共存于中国东南部的亚热带森林中。为探究常绿和落叶树种应对亚热带磷限制所采用的碳获取策略,我们选取阳际峰常绿阔叶林中75种共存的木本植物,包括44种常绿树种和31种落叶树种,测定了其叶片的光合和呼吸速率,以及与碳(C)、氮(N)和磷(P)利用效率和再吸收效率的相关性状。落叶树种的光合氮利用效率(PNUE)、单位氮和磷的呼吸速率(Rd,NRd,P)均显著高于常绿树种,但光合磷利用效率(PPUE)在二者之间无显著差异。对于任意给定的叶片P,常绿树种的碳利用效率(CUE)高于落叶树种。此外,落叶和常绿植物的氮再吸收效率(NRE)、磷再吸收效率(PRE)和N:P均无显著差异。这些结果表明,常绿树种维持高CUE使其在P限制的亚热带森林中成为优势树种。这些结果对其他生物群落中落叶和常绿物种的养分策略比较具有重要意义,也为未来的气候变化下的亚热带森林的群落动态建模提供了新见解。

关键词: 光合养分利用效率, 碳利用效率, 氮吸收效率, 磷吸收效率, 物种共存