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持续干旱下沙地樟子松幼苗C、N、P化学计量变化规律

王凯1*,沈潮1,宋立宁2,吕林有3,张大鹏1   

  1. 1辽宁工程技术大学环境科学与工程学院, 辽宁阜新 123000;  2中国科学院沈阳应用生态研究所, 沈阳 110016;  3辽宁省沙地治理与利用研究所, 辽宁阜新 123000)
  • 出版日期:2020-07-10 发布日期:2021-01-09

Variations in C, N and P stoichiometry of Pinus sylvestris var. mongolica seedlings under continuous

WANG Kai1*, SHEN Chao1, SONG Li-ning2, LÜ Lin-you3, ZHANG Da-peng1   

  1. (1College of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, Liaoning, China; 2Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; 3Liaoning Institute of Sandy Land Control and Utilization, Fuxin 123000, Liaoning, China).
  • Online:2020-07-10 Published:2021-01-09

摘要: 为明确沙地樟子松幼苗在干旱胁迫过程中C、N和P化学计量的变化规律及分配特征,通过盆栽试验,对2年生沙地樟子松幼苗进行自然干旱处理,当土壤含水量下降到田间持水量的60%、40%、30%和20%时,测定各器官(当年生叶、一年生叶、茎、粗根和细根)的C、N和P含量。结果表明:持续干旱过程中,沙地樟子松幼苗N、P含量及C∶P和N∶P变异系数在粗根中最大,C含量变异系数在细根中最大;C、P含量及C∶P变异系数在一年生叶中最小,N含量和C∶N变异系数在当年生叶中最小,N∶P变异系数在茎中最小。随着田间持水量下降,C含量在当年生叶中先下降再上升后下降,在一年生叶、茎和粗根中先升高后降低,在细根中先下降后上升;N含量在当年生叶中先下降后上升,在一年生叶、茎和粗根中下降,在细根中先降低再升高后降低;P含量在当年生叶中上升,在一年生叶、茎、粗根和细根中先下降后上升;C∶N在一年生叶、茎、粗根和细根中增加,C∶P在当年生叶中下降,各器官N∶P均降低。相同元素在不同器官间紧密相关,而不同元素间相关性较差。因此,随着干旱加剧,沙地樟子松幼苗生长受N限制逐渐增强,N利用效率提高,各元素在叶和茎中稳定性高于粗根和细根。

关键词: 玉米与马铃薯间作, 养分利用, 养分吸收, 间作优势

Abstract: We examined the stoichiometric responses of Pinus sylvestris var. mongolica seedlings to drought stress by growing two-year-old P. sylvestris var.mongolica seedlings in pots and setting continuous natural drought treatment. We measured C, N and P contents in different organs (current-year needle, one-year-old needle, stem, coarse root and fine root) of the seedlings under the conditions of 60%, 40%, 30% and 20% of field waterholding capacity. Under drought stress, the variation coefficients of N and P content, C∶P and N∶P were the highest in coarse root, and the variation coefficient of C content was the highest in fine root. Meanwhile, the variation coefficients of C and P content and C∶P were the lowest in one-year-old needle, the minimum variation coefficients of N content and C∶N were found in currentyear needle, and the minimum variation coefficient of N∶P was found in stem. With decreasing soil field capacity, C content in current-year needle showed a hump change, whereas it elevated and then reduced in one-year-old needle, stem and coarse root, and it decreased and then increased in fine root. Nitrogen content decreased and then increased in current-year needle, but it declined in one-year-old needle, stem and coarse root, whereas it showed a hump pattern in fine root. Phosphorus content was promoted in current-year needle, but it declined and then increased in one-year-old needle, stem, coarse root and fine root. In addition, C∶N increased in one-year-old needle, stem, coarse root and fine root, but C∶P declined in currentyear needle, while N∶P decreased in all organs. There were close correlations among different organs for the same element but not for different elements. Therefore, with increasing drought stress, N limitation was gradually aggravated to the growth of P. sylvestris var.mongolica seedlings, and N use efficiency improved. Meanwhile, the contents of various elements were more stable in needle and stem than that in coarse root and fine root.

Key words: nutrient utilization, intercropping advantage., nutrient uptake, maize and potato intercropping