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林业科学 ›› 2022, Vol. 58 ›› Issue (8): 99-108.doi: 10.11707/j.1001-7488.20220810

• 研究论文 • 上一篇    下一篇

不同火烈度条件下油松枝功能性状的响应

顾泽1,2,刘晓东1,3,陈锋1,*   

  1. 1. 北京林业大学森林资源生态系统过程北京市重点实验室 北京 100083
    2. 中国林业集团有限公司 北京 100036
    3. 森林草原火灾风险防控应急管理部重点实验室 北京 102202
  • 收稿日期:2022-04-19 出版日期:2022-08-25 发布日期:2022-12-19
  • 通讯作者: 陈锋
  • 基金资助:
    国家重点研发计划项目(2020YFC1511601)

Response of Twig Functional Traits of Pinus tabuliformis to Different Fire Severities

Ze Gu1,2,Xiaodong Liu1,3,Feng Chen1,*   

  1. 1. Beijing Key Laboratory for Forest Resources and Ecosystem Processes, Beijing Forestry University Beijing 100083
    2. China Forestry Group Corporation Beijing 100036
    3. Key Laboratory of Forest and Grassland Fire Risk Prevention of Ministry of Emergency Management Beijing 102202
  • Received:2022-04-19 Online:2022-08-25 Published:2022-12-19
  • Contact: Feng Chen

摘要:

目的: 研究油松枝功能性状在不同火烈度条件下的适应性变化, 揭示油松在不同火环境下的生态权衡策略与适应机制, 为火后油松的生态恢复提供理论基础。方法: 以山西省沁源县火烧迹地内(未过火、轻度火烧、中度火烧)的油松为研究对象, 根据单因素方差分析与Pearson相关分析研究枝功能性状(枝组织密度、枝氮含量、枝磷含量、枝有机碳含量、枝氮磷比、枝碳磷比、枝碳氮比)在不同火烈度条件下的差异性及相关性, 并利用主成分分析探究不同火烈度条件下的油松枝经济谱变化趋势。结果: 1) 在3种火烈度下, 枝碳磷比的变异系数最大, 枝有机碳含量的变异系数最小。随火烈度增加, 枝组织密度先降低后升高, 对照枝组织密度显著高于轻度火烧(11.8%), 显著高于中度火烧(5.6%); 枝磷含量升高, 在中度火烧显著高于对照(27.8%); 枝氮磷比降低, 在中度火烧显著低于对照(19.1%)。其余枝功能性状不随火烈度变化产生显著差异。2)不同火烈度条件下, 枝功能性状的相关性存在共性结果: 枝氮含量与枝碳氮比呈极显著负相关、枝磷含量与枝氮磷比和枝碳磷比呈极显著负相关、枝氮磷比与枝碳磷比呈极显著正相关。因此, 上述性状间的耦合关系在油松枝功能性状中最为稳定。然而, 火烈度的增加减弱了部分性状间的关联: 相比于对照和轻度火烧, 在中度火烧下, 枝氮含量与枝磷含量和枝碳磷比、枝磷含量与枝碳氮比、枝碳磷比与枝碳氮比均无显著相关性。3)火烧迹地内生长的油松存在枝经济谱, 沿着"未过火—轻度火烧—中度火烧"的火烈度, 枝条的资源权衡策略向"快速投资—收益型"移动, 枝条的生长速率会加快。结论: 火烈度对油松枝功能性状产生了显著影响, 改变了养分元素的分配策略, 油松枝条的生长恢复在轻度和中度火烧条件下会加快。

关键词: 油松, 林火, 火烈度, 枝功能性状, 枝经济谱

Abstract:

Objective: Forest fire is one of the important disturbance factors in forest ecosystem. Plants have ecological adaptability to different forest fire environments. Study on the adaptive changes of twig functional traits of Pinus tabuliformis under different fire severities would help to reveal the ecological trade-off strategies and adaptive mechanisms of P. tabulaeformis under different fire environments, and provide a theoretical basis for the ecological restoration of P. tabuliformis after fire. Method: P. tabuliformis in the burned area (unburned, light burned, moderate burned) of Qinyuan county, Shanxi Province was targeted. The differences and correlations among twig functional traits (twig tissue density, twig nitrogen content, twig phosphorus content, twig organic carbon content, twig nitrogen-phosphorus ratio, twig carbon-phosphorus ratio, twig carbon-nitrogen ratio) under different fire severities were studied by one-way analysis of variance and Pearson correlation analysis. The change trend of economic spectrum of P. tabuliformis twigs under different fire severities was explored by principal component analysis. Result: 1) Under three fire severities, the variation coefficient of twig carbon-phosphorus ratio was the largest, and that of twig organic carbon content was the smallest. With the increase of fire severity, twig tissue density first decreased and then increased. Twig tissue density in the control was significantly higher than that in the light burned by 11.8%, and significantly higher than that in the moderate burned by 5.6%. Twig phosphorus content increased with the increase of fire severity, which of the moderate burned was significantly higher than that of the control by 27.8%. Twig nitrogen-phosphorus ratio decreased with the increase of fire severity, which in the moderate burned was significantly lower than that of the control by 19.1%. There were no significant differences among other twig functional traits with the change of fire severity. 2) Under different fire severities, there were similar results in the correlation of twig functional traits: there was a highly significant negative correlation between twig nitrogen content and twig carbon-nitrogen ratio, and a highly significant negative correlation between twig phosphorus content, and twig nitrogen-phosphorus ratio, as well as twig carbon-phosphorus ratio, and a highly significant positive correlation between twig nitrogen-phosphorus ratio and twig carbon-phosphorus ratio. Therefore, the coupling relationship between the above traits was the most stable in the twig functional traits of P. tabuliformis. However, the increase of fire severity weakened the correlation between some traits. Compared with the control and the light burned, there were no significant correlations among twig nitrogen content, twig phosphorus content and twig carbon-phosphorus ratio, between twig phosphorus content and twig carbon-nitrogen ratio, and between twig carbon-phosphorus ratio and twig carbon-nitrogen ratio under the moderate burned. 3) There existed a twig economic spectrum of P. tabuliformis growing in the burned area. Along the fire severity of 'unburned-light burned-moderate burned', the resource trade-off strategy of twig moved to 'fast investment-benefit type', indicating that the growth rate of twigs would be accelerated. Conclusion: Fire severity has a significant effect on the functional traits of P. tabuliformis twigs, changes the allocation strategy of nutrient elements. The growth recovery of P. tabuliformis twig would be accelerated under light and moderate burned conditions. The research result can provide theoretical support for ecological restoration of burned P. tabuliformis.

Key words: Pinus tabuliformis, forest fire, fire severity, twig functional trait, twig economic spectrum

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