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生态学杂志 ›› 2021, Vol. 40 ›› Issue (3): 664-671.doi: 10.13292/j.1000-4890.202103.023

• 研究报告 • 上一篇    下一篇

遮荫对青桐幼苗生长性状与化学计量特征的影响  

智西民,王梦颖,牛畔青,杨瑶,蒋梦琳,胡云一,陈良华,高顺*     

  1. (四川农业大学林学院, 长江上游森林资源保育与生态安全国家林业和草原局重点实验室, 成都 611130)
  • 出版日期:2021-03-10 发布日期:2021-03-15

Effects of shading on the growth indices and stoichiometric characteristics of Firmiana platanifolia seedlings.

ZHI Xi-min, WANG Meng-ying, NIU Pan-qing, YANG Yao, JIANG Meng-lin, HU Yun-yi, CHEN Liang-hua, GAO Shun*   

  1. (National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Faculty of Forestry, Sichuan Agricultural University, Chengdu 611130, China).
  • Online:2021-03-10 Published:2021-03-15

摘要: 营养元素含量及化学计量比可反映植物器官营养元素的分配及互作关系,亦可反映其营养利用效率及生长环境的养分限制状况。以青桐(Firmiana platanifolia)幼苗为材料,分析4种不同光强(全光照,50%、75%和95%遮荫)对青桐幼苗生长,C、N、P、K含量及其化学计量特征的影响。结果表明:遮荫对青桐幼苗的生长性状、生物量、元素含量和积累量及化学计量比均有显著影响(P<0.05)。苗高和比叶面积随遮荫强度增加而升高,而地径和粗壮度随遮荫强度增加而减小。总生物量在75%遮荫下最大,在95%遮荫下最小。在各遮荫处理下,叶片C、N、P、K含量均大于根和茎,且N含量顺序为叶>根>茎,K含量顺序为叶>茎>根。C、P、K积累量随遮荫强度增大而增加,在75%遮荫下达到最大值,而在95%遮荫下达到最小值。青桐幼苗C∶N和C∶P呈现出相同的变化趋势,随遮荫强度变大先增加后减小,均在50%遮荫下达最大值。青桐各器官N∶P远低于14,即青桐幼苗在不同遮荫条件下的生长严重受N限制。这些结果说明,遮荫可调节青桐幼苗在不同光环境中的养分积累与分配,进而影响生物量。因此,青桐苗期培育宜选75%遮荫,有助于苗高、比叶面积、生物量、养分含量和积累量的增加,而过度遮荫可抑制幼苗生长发育。

关键词: 遮荫, 生物量, 元素含量, 积累量, 化学计量比

Abstract: The content and stoichiometry of nutrients in plant tissue reflect the distribution and interaction of elements in plants, as well as plant nutrient use efficiency and the nutrient limitation of the environment. Here, we analyzed the effects of four light intensities (full light, 50%, 75% and 95% shading) on the growth and the contents and stoichiometric characteristics of C, N, P, and K in Firmianaplatanifolia seedlings. Results showed that shading significantly affected growth traits, biomass, element content and accumulation, and stoichiometric ratio of seedlings (P<0.05). The height and specific leaf area of seedlings increased with the increases of shading intensity, while the basal diameter and roughness decreased. The total biomass was the highest under 75% shade and the lowest under 95% shade. Across those shading treatments, foliar C, N, P and K concentrations were higher than that in roots and stems. The N content in different organs followed the order of leaf>root>stem, while K content was in order of leaf>stem>root. The total accumulation of C, P and K increased with the increases of shading intensity, with the maximum and minimum values occurring under 75% shade and 95% shade, respectively. The changes of C∶N and C∶P of seedlings were similar, which increased first and then decreased with the increases of shading intensity, and reached the maximum value under 50% shading. N∶P in each organ was much lower than 14, indicating that seedling growth under different shading conditions was severely restricted by nitrogen availability. Our results highlight that shading can regulate the nutrient accumulation and distribution of F.platanifolia seedlings under different light environments, with consequences on biomass production. The 75% shading is optimal for seedling breeding, which helps to increase the height, specific leaf area, biomass, nutrient content and accumulation. Excessive shading might inhibit seedling growth.

Key words: shading, biomass, element content, accumulation, stoichiometric ratio.