不同火烈度火烧迹地内油松叶功能性状的变化

叶功能性状对林火的响应是林火生态领域的研究热点之一,研究火后油松叶功能性状变化能够揭示油松为适应火环境形成的生长策略,为促进油松火后恢复提供参考。以山西省沁源县火烧迹地内油松为研究对象,选择当年生叶片分析叶功能性状在不同火烈度(未过火、轻度火烧、中度火烧)火烧迹地间的变化规律,并研究不同火烧迹地内叶经济谱的变化特征。结果表明: 除氮磷比外,叶功能性状在不同火烈度的火烧迹地间存在显著差异,其中,叶面积的差异最为明显,是最敏感的性状。随火烧迹地内火烈度的增加,叶面积、叶厚度、叶干物质含量、叶氮含量和叶磷含量升高,比叶面积、叶有机碳含量降低。部分叶功能性状间存在显著的相关关系,但其相关性在不同火烈度的火烧迹地间存在差异。叶经济谱沿着“未过火-轻度火烧-中度火烧”的火烧迹地环境总体向“快速投资-收益型”的资源权衡策略移动,低烈度火烧迹地内油松的生长恢复会加快。

Changes of leaf functional traits of Pinus tabuliformis in burned areas with different fire severities

The response of leaf functional traits to forest fire is one of the research hotspots in the forest fire ecology. Studying post-fire changes in leaf functional traits of Pinus tabuliformis can reveal its growth strategies to adapt to fire environment and provide reference for the post-fire recovery. We analyzed the changes of leaf functional traits in burned areas with different fire severities (unburned, light burn and moderate burn) in Qinyuan County burned area of Shanxi Province, and studied the variation characteristics of leaf economic spectrum in different burned areas. The results showed that there were significant differences in burned areas with different fire severities for all leaf functional traits except N/P. Among them, the difference of leaf area was the most obvious, which was the most sensitive trait. With the increases of fire severity in burned areas, leaf area, leaf thickness, leaf dry matter content, leaf nitrogen content and leaf phosphorus content increased, while specific leaf area and leaf organic carbon content decreased. There were significant correlations among some leaf functional traits, with the correlations being distinct in burned areas with different fire severities. The leaf economic spectrum moved from ‘unburned-light burn-mode-rate burn’ to the resource trade-off strategy of ‘rapid investment-return type’ along the fire environment. The recovery of P. tabuliformis would be accelerated in burned area with low fire severity.