草本竞争对云杉更新苗叶片生物量和形态特性的影响

Effects of Herbal Competition on Leaf Biomass and Morphological Characteristics of Picea asperata Regenerated Seedling

以关帝山晚期演替树种云杉更新幼苗为研究对象,分析草本竞争对云杉幼苗叶片特性的影响;利用冗余分析探究草本和环境因子对云杉更新幼苗叶片特性间的竞争强度,进一步探究草本竞争及其环境因子与更新幼苗叶片特性间的作用机制和途径。结果表明:在不同草本株数竞争下,高、中、低3种草本株数竞争对更新苗叶片特征具有显著影响。不同草本株数竞争对云杉更新幼苗当年生叶片的表面积、生物量、比叶面积具有极显著影响,对往年生、草上叶片和草下叶片的表面积、生物量有极显著影响。草本竞争和环境因子对更新苗叶片特性影响的顺序为冠幅>苗龄>草本株数>草本种类,除了更新苗自身的特性,草本竞争对叶片特性的影响占重要地位。苗龄与由草本株数、草本种类和草本盖度构建的潜变量F1对云杉更新苗叶片表面积具有正向直接影响;F1、冠幅、苗龄与碱解氮对更新苗叶片比叶面积和生物量产生正向直接作用。

This experiment took the regenerating saplings of late succession tree species Picea asperata in Guandi Mountain as the research object,analyzed the influence of herb competition on the leaf characteristics of P.asperata seedlings,explored the competition intensity between herbs and environmental factors on the leaf characteristics of P.asperata seedlings by using redundancy analysis,and further explored the mechanism and path of herb competition,environmental factors and the leaf characteristics of the seedlings.The results showed that under the competition of different herb plant numbers,the competition among the low number of 3 herbs had a significant effect on the leaf characteristics of regeneration seedlings.The competition of different herbaceous plant numbers has a very significant impact on the surface area(SA),biomass(BIO),specific leaf area(SLA)of the current year's leaves of spruce regeneration seedlings,and has a very significant impact on the surface area and biomass of the previous year's,above grass's and under grass's leaves.The order of influence of herbaceous competition and environmental factors on leaf characteristics of regeneration seedlings was crown width>seedling age>number of herbaceous plants>herbaceous species.In addition to the characteristics of regeneration seedlings,herbaceous competition played an important role in leaf characteristics;seedling age and potential variable F1 constructed by herbaceous trees,herbaceous species and herbaceous coverage have a direct positive effect on leaf surface area of spruce regeneration seedlings;F1,crown width,seedling age and alkali hydrolyzed nitrogen had a direct positive effect on the specific leaf area and biomass of the regenerated seedlings.