高级检索
    张俪予, 张军辉, 张蕾, 陈伟, 韩士杰. 兴安落叶松和白桦细根形态对环境变化的响应[J]. 北京林业大学学报, 2019, 41(6): 15-23. DOI: 10.13332/j.1000-1522.20180396
    引用本文: 张俪予, 张军辉, 张蕾, 陈伟, 韩士杰. 兴安落叶松和白桦细根形态对环境变化的响应[J]. 北京林业大学学报, 2019, 41(6): 15-23. DOI: 10.13332/j.1000-1522.20180396
    Zhang Liyu, Zhang Junhui, Zhang Lei, Chen Wei, Han Shijie. Response of fine root morphology of Larix gmelinii and Betula platyphylla to environmental changes[J]. Journal of Beijing Forestry University, 2019, 41(6): 15-23. DOI: 10.13332/j.1000-1522.20180396
    Citation: Zhang Liyu, Zhang Junhui, Zhang Lei, Chen Wei, Han Shijie. Response of fine root morphology of Larix gmelinii and Betula platyphylla to environmental changes[J]. Journal of Beijing Forestry University, 2019, 41(6): 15-23. DOI: 10.13332/j.1000-1522.20180396

    兴安落叶松和白桦细根形态对环境变化的响应

    Response of fine root morphology of Larix gmelinii and Betula platyphylla to environmental changes

    • 摘要:
      目的细根是树木吸收养分和水分的主要器官,在陆地生态系统养分循环和能量流动中发挥着重要作用。尽管人们已经理解了细根对碳和养分循环的重要性,但是对细根在不同环境条件下的响应和适应机制仍需深入探索。本文通过比较同一树种在不同环境条件下细根形态的可塑性以及不同树种细根形态上的差异,了解环境因子和外生菌根侵染对细根形态特征的影响。
      方法以东北大兴安岭和小兴安岭多年冻土区(伊春冻土退化区、南翁河冻土退化敏感区、漠河永久冻土区)的优势树种兴安落叶松和白桦为研究对象,在植物生长季节采样,挖掘法获取完整根系,测定初级发育根(1、2级根)的细根直径,比根长,比表面积,组织密度,等形态特征和外生菌根侵染率。
      结果土壤有效氮、土壤全碳以及生长季月均温是影响细根形态特征的主要因素。在伊春冻土退化区、南翁河冻土退化敏感区、漠河永久冻土区条件下,兴安落叶松细根形态差异均不显著(P > 0.05),外生菌根侵染率差异显著(P < 0.05);白桦细根直径、比根长、比表面积和外生菌根侵染率差异显著(P < 0.05),组织密度差异不显著(P > 0.05),白桦细根直径在南翁河冻土退化敏感区最小,而比根长和比表面积最大。兴安落叶松和白桦两树种之间细根形态特征和外生菌根侵染率存在较大差异(P < 0.05)。兴安落叶松和白桦菌根侵染率与细根直径显著正相关(r = 0.64,P < 0.01;r = 0.61,P < 0.01),与其他细根形态特征相关性不显著。
      结论土壤养分和生长季月均温是影响不同冻土区兴安落叶松和白桦细根形态的主要因素,兴安落叶松主要依赖外生菌根真菌适应环境变化,而白桦则是通过调整细根直径、比根长、比表面积以及外生菌根侵染率以响应环境空间异质性,外生菌根真菌的存在是兴安落叶松和白桦的重要替代性吸收策略。

       

      Abstract:
      ObjectiveFine root is the primary organ for trees to absorb nutrients and water, and plays a significant role in the nutrient cycling and energy flowing of terrestrial ecosystems. Despite our understanding of the importance of fine roots for carbon and nutrient cycling, lack of understanding of acclimation and adaptation mechanisms of fine roots under different environmental conditions is a key shortcoming in the future projection about the consequences of climate change. The purpose of this paper is to compare the plasticity of fine root morphology under different environmental conditions and the morphology of fine roots of two tree species, and to analyze the effects of environmental factors and ectomycorrhizal colonization on fine root morphology.
      MethodThis paper takes the dominant species of Larix gmelinii and Betula platyphylla in the permafrost regions of the Xing ’an Mountains (Yichun permafrost degraded area, Nanwenghe permafrost degraded sensitive area, Mohe permafrost area of northeastern China) as the research object, the intact root segments were sampled by excavation method in the growing season. We measured the diameter, specific root length, specific surface area, tissue density and ectomycorrhizal colonization rate of primary development roots (1st and 2nd root).
      ResultSoil available nitrogen, soil total carbon and monthly mean temperature of growing season were the main factors affecting the morphology. The fine root morphology of Larix gmelinii differed little (P > 0.05) among the three research sites, and the ectomycorrhizal colonization rate made significant difference (P < 0.05). For Betula platyphylla, the diameter, specific root length, specific surface area and ectomycorrhizal colonization rate were significantly different (P < 0.05), but tissue density did not differ (P > 0.05). The diameter of fine root of Betula platyphylla was the smallest in the Nanwenghe permafrost degraded sensitive area, but specific root length and specific surface area were the largest; the morphological characteristics of fine roots and the colonization rate of ectomycorrhizal fungi exhibited different between two tree species; and the colonization rates of Larix gmelinii and Betula platyphylla were significantly positively correlated with fine root diameter (r = 0.64, P < 0.01; r = 0.61, P < 0.01).
      ConclusionThe soil nutrient and the monthly mean temperature of the growing season are the main factors influencing the morphology of fine roots. Larix gmelinii mainly relies on ectomycorrhizal fungi to adapt to environmental changes, while Betula platyphylla is adjusted by fine root diameter, specific root length and specific surface area and ectomycorrhizal infection rate in response to environmental spatial heterogeneity and the existence of ectomycorrhizal fungi is a crucial alternative absorption strategy.

       

    /

    返回文章
    返回