不同混交比例的杉阔混交林对林下物种多样性和土壤养分的影响  

Effects of fir and broad-leaved mixed forest with different mixing proportions on the species diversity and soil nutrients under the forest

作　　者：石昊楠 李伟坡[2] 李智华 王义贵 杨小周 SHI Haonan;LI Weipo;LI Zhihua;WANG Yigui;YANG Xiaozhou(Northwest Survey,Planning and Design Institute of the State Forestry and Grassland Administration,Xi’an 710048,Shaanxi,China;Central South University of Forestry and Technology,Changsha 410000,Hunan,China)

机构地区：[1]国家林业和草原局西北调查规划设计院,陕西西安710048 [2]中南林业科技大学,湖南长沙410000

出　　处：《中南林业科技大学学报》2022年第12期34-41,共8页Journal of Central South University of Forestry & Technology

基　　金：国家重点研发计划项目“重点区域速丰林丰产增效技术集成与示范”(2017YFD0601201)。

摘　　要：【目的】为了研究不同混交比例的杉木针阔混交林对林下物种多样性和土壤养分的影响。【方法】以青羊湖林场的5种不同混交比例的杉木针阔混交林为研究对象,采用典型抽样法,按照群落中杉木材积所占的不同比例(50%、60%、70%、80%、90%),把调查的森林群落分为5种类型,分别监测各类型群落林下物种组成及多样性差异,测定土壤理化性质,以及林下物种多样性与土壤养分的相关性。【结果】1)不同混交比例的针阔混交林林下物种组成和优势种存在差异。在杉木比例50%的混交林中,灌木层的优势种为胡枝子和楤木,草本层优势种为狗脊蕨等阴生性植被;在杉木比例90%的混交林中,灌木层优势种为山苍子等阳生性植物,草本层优势种为瓜蒌等阳生性植被。灌草的物种多样性在杉木比例50%与60%的混交林中达到最大值。2)不同土层间各种土壤养分变化趋势基本一致,不同混交比例间土壤养分变化趋势不同。除了pH、全钾、速效磷外,其他土壤养分受混交比例的影响相似,均随杉木比例的增加而减小。更多的土壤养分在杉木比例50%下达到最大。3)土壤容重、有机质、碱解氮、速效钾和有效硼与灌草层物种多样性指数的相关性最为密切。【结论】杉木比例在50%~70%之间更有利于土壤养分的累积和林下物种多样性的稳定。在与本研究区立地条件相似地区营造杉阔混交林时,可将杉木比例营造为50%~70%,本研究结果可对杉阔混交林的可持续经营提供理论指导。【Objective】This work was designed to study the effects of different mixing proportions of fir and broad-leaved mixed forest on understory species diversity and soil nutrients.【Method】Five kinds of Chinese fir coniferous and broad-leaved mixed forests with different mixing proportions in Qingyanghu forest farm were selected as the research objects.According to the proportion of Chinese fir volume(50%,60%,70%,80%,90%),the investigated forest communities were divided into five types.The differences in species composition and diversity,soil physical and chemical properties,and species abundance under the forest were monitored.The correlation between soil samples and soil nutrients was determined.【Result】1)There were differences in the species composition and dominant species among the coniferous and broad-leaved mixed forests with different mixing proportions.In the mixed forest with 50%of fir,Lespedeza and Aralia were the dominant species in the shrub layer,while the dominant species in the herb layer were Woodwardia japonica and other shade vegetation.In the mixed forest with 90%of Chinese fir,the dominant species in the shrub layer were Litsea cubeba(Lour)Pers.and other sun plants,while the dominant species in the herb layer was Trichosanthes kirilowii Maxim.The species diversity of shrub and grass was the highest in the mixed forest with 50%and 60%of fir.2)The changing trend of soil nutrients in different soil layers was the same,while the changing trend of soil nutrients was different among different mixing proportions.Except for pH,total K and available P,other soil nutrients were affected by the mixing proportion,which decreased with the increase of Chinese fir proportions.More soil nutrients reached the maximum when the proportion of fir was 50%.3)Soil bulk density,organic matter,available nitrogen,available K and available B were closely related to the species diversity index of shrub and grass layers.【Conclusion】A proportion of Chinese fir between 50%and 70%is more conducive to the accumulat

关 键 词：针阔混交林 混交比例 土壤养分 林下植被 物种多样性 

分 类 号：S725.2[农业科学—林木遗传育种]