Chin J Plant Ecol ›› 2026, Vol. 50 ›› Issue (2): 306-317.DOI: 10.17521/cjpe.2025.0097  cstr: 32100.14.cjpe.2025.0097

• Research Articles • Previous Articles     Next Articles

Important role of organ age in variation and coordination of stoichiometry in Pinus tabuliformis leaves, twigs and roots

YU Jiang-Shan1, XU Hao2,3,4, GUO Yong-Zhong2,3,4, HOU Ji-Hua1,*()   

  1. 1 School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
    2 Institute of Forestry and Grassland Ecology, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan 750002, China
    3 Ningxia Key Laboratory of Desertification Control and Soil and Water Conservation, Yinchuan 750002, China
    4 Research Center for Ecological Restoration and Multi-Functional Forestry of Ningxia, Yinchuan 750002, China
  • Received:2025-03-19 Accepted:2025-05-13 Online:2026-02-28 Published:2026-04-01
  • Contact: HOU Ji-Hua
  • Supported by:
    National Natural Science Foundation of China(31872683)

Abstract:

Aims As a dominant and keystone species in temperate coniferous forests of China, Pinus tabuliformis exhibits strong environmental adaptability. Investigating the stoichiometric characteristics of leaves, twigs and roots in both current-year (newly developed) and perennial (≥1 year old, mature) organs, as well as their relationships, is essential for understanding intraspecific variation and plant resource allocation strategies.

Methods This study was conducted in natural P. tabuliformis forests across nine regions in China. A total of 81 individual trees were sampled to measure the carbon (C), nitrogen (N) and phosphorus (P) content in their six organs (current-year leaves, perennial leaves, current-year twigs, perennial twigs, absorptive roots and transport roots).

Important findings (1) Current-year organs exhibited higher N and P contents but lower C:N, C:P, and N:P ratios compared to perennial organs. Stoichiometric traits showed considerable intraspecific variation across organs of different ages, with organ age identified as the primary factor influencing these differences. (2) Standardized major axis analysis revealed that perennial leaves had higher P content per unit mass than current-year leaves, whereas current-year twigs and absorptive roots showed higher C, N and P contents than their perennial counterparts (perennial twigs and transport roots). (3) Additionally, absorptive roots had significantly higher C, N and P contents per unit mass than both current-year leaves and twigs. (4) Redundancy analysis indicated that the main environmental drivers of stoichiometric traits in current-year and perennial leaves were mean annual temperature and soil P content, respectively. The most significant environmental factors affecting the stoichiometric traits of current-year and perennial twigs were annual precipitation and soil P content, respectively; while the main environmental factors influencing absorptive and transport roots were soil moisture and soil N content, respectively. This study reveals the resource allocation strategies and environmental adaptability of leaves, twigs, and roots across different age classes in P. tabuliformis. The findings demonstrate that the studies on the stoichiometry of evergreen species should fully consider age-related differences among organs, which is essential for elucidating their nutrient allocation strategies and environmental adaption mechanisms.

Key words: intraspecific variation, Pinus tabuliformis, leaf, twig, root, age, stoichiometric characteristic