JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2022, Vol. 46 ›› Issue (3): 74-82.doi: 10.12302/j.issn.1000-2006.202008002

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Changes of seedling growth and C、N、P stoichiometric characteristics in Chinese fir under shading

LIU Qingqing1(), HUANG Zhijun1, MA Xiangqing1, WANG Zhengning1, XING Xianshuang2, LIU Bo1,3,*()   

  1. 1. College of Forestry, Fujian Agriculture and Forestry University, Chinese Fir Engineering Technology Research Center, National Forestry and Grassland Administration, Fuzhou 350002, China
    2. Shandong Hydrological Center, Ji’nan 250002, China
    3. College of Life Sciences, Qufu Normal University, Qufu, 273165, China
  • Received:2020-08-02 Accepted:2021-10-14 Online:2022-05-30 Published:2022-06-10
  • Contact: LIU Bo E-mail:liuqqing222@126.com;lboshandong@126.com

Abstract:

【Objectives】To explore the adaptive strategy of seedlings under different shade intensities, the growth, biomass accumulation and allocation as well carbon (C), nitrogen (N) and phosphorus (P) accumulation, allocation and stoichiometric characteristics were measured in different organs of Chinese fir seedlings. The results help to elucidate changes in C, N, P elements under different shading treatments, and provide a theoretical basis for cultivation at the seedling stage, stand light environment regulation and management. 【Method】After one year of growth, Chinese fir seedlings were selected as the research object in this study, and five different light intensities were set up with artificial shading 0% (as control, no shade), 40%, 60%, 85% and 95% shading. The experiment was undertaken over one year. The height increment, diameter increment, biomass accumulation and allocation, root to shoot ratios, C, N, P accumulations, and their stoichiometric characteristics were measured at the end of the experiment in different organs of Chinese fir seedlings under various shade intensities.【Result】(1) The height of seedlings increased as the shade increased, while the diameter significantly decreased. Biomass of the root, stem, leaf, total, and root to shoot ratios decreased as the shade increased, while the stem and leaf biomass ratios increased. (2) The accumulations of C, N, P of root, stem, leaf and the total accumulations decreased with the increased of shade intensities. The C and N distribution ratios increased in the aboveground part (stem and leaf) of the seedlings, and decreased in the underground part of the seedling (root). (3) C/N (the mass ratio, same as below) and C/P of seedlings showed the same change trend, which initially increased and then decreased with increasing shading intensities. The N/P in each organ was lower than 14, indicating that Chinese fir seedling growth under different shading intensities was restricted by nitrogen. 【Conclusion】Chinese fir seedlings could regulate nutrient accumulation and distribution under different shading treatments, affecting biomass accumulation. Chinese fir seedlings showed different growth and physiological strategies under different shading intensities, such as greater growth in height, slower growth in diameter, with biomass allocation being invested in the aboveground parts under high shading intensities. Seedlings gradually changed from “short and thick” to “thin and tall”. However, the excessive shading may inhibit seedling growth, and result in less biomass accumulations, and low C, N, P accumulations.

Key words: Chinese fir (Cunninghamia lanceolata) seedling, shade intensities, stoichiometric characteristics, nutrient utilization strategy

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