光环境差异对杉木幼林林下植被多样性及根系种间竞争的影响  

Effects of Light Environment Differences on Understory Vegetation Diversity and Root Interspecific Competition of Young Cunning-hamia lanceolata Plantation

作　　者：林芳馨 胥清利 曲晓宇 黄樱 陈宇[1,3,4] 林开敏 曹光球[1,3,4] Lin Fangxin;Xu Qingli;Qu Xiaoyu;Huang Ying;Chen Yu;Lin Kaimin;Cao Guangqiu(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou Fujian 350002,China;Pushang State-owned Forest Farm of Shunchang County,Nanping Fujian 353200,China;Chinese Fir Engineer Research Center of National Forestry and Grassland Administration,Fuzhou Fujian 350002,China;Fujian Provincial Key Laboratory in Universities on Forest Stress Physiology,Ecology and Molecular Biology,Fuzhou Fujian 350002,China)

机构地区：[1]福建农林大学林学院,福建福州350002 [2]福建省顺昌埔上国有林场,福建南平353200 [3]国家林业和草原局杉木工程技术研究中心,福建福州350002 [4]林木逆境生理生态及分子生物学福建省高校重点实验室,福建福州350002

出　　处：《西南林业大学学报（自然科学）》2024年第5期35-43,共9页Journal of Southwest Forestry University：Natural Sciences

基　　金：国家重点研发计划项目(2016YFD0600301)资助。

摘　　要：为了解光环境变化与林下植被多样性、根系竞争的相关关系,以5年生不同造林密度(833、2500、6667株/hm2)杉木幼林为研究对象,测定分析林内光环境、林下植被多样性变化和根系竞争关系,探究造林密度引起的光环境差异对林下植被组成及根系竞争的影响。结果表明:造林密度增大显著影响林内光环境,833、2500、6667株/hm^(2)密度冠下总辐射分别为77.82、31.94、14.03μmol/(m^(2)·s),林下总照度分别为5893.13、1130.7、761.5 Lx。草本层Shannon-Wiener指数、Pielou均匀度指数随密度增加呈先增后降的规律;灌木层Simpson优势度指数、Pielou均匀度指数随造林密度的增大而下降。随密度的增大,杉木细根生物量与杉木根系竞争指数均逐渐增加,而林下植被生物量及其根系竞争指数逐渐下降。光环境相关指标与灌木层Pielou均匀度指数、草本层Simpson优势度指数呈显著正相关,与杉木根系竞争指数呈显著负相关,与林下植被根系竞争呈极显著正相关。因此,造林密度变化显著影响林内光环境,光环境相关指标随着造林密度增加而降低,造成杉木幼林林下植被生物量降低并影响林下植被多样性变化,并增强了杉木的根系竞争能力。综合杉木的生长状况,2500株/hm2为杉木适宜的造林密度更适合构建优质杉木人工林。The study focuses on 5-year-old Cunninghamia lanceolata saplings at 3 afforestation densities(833,2500,6667 trees/hm2),analyzing the forest light environment,changes in understory vegetation diversity,and root competition to examine the effects of afforestation density on understory vegetation composition and root competition.The findings revealed that increased afforestation density significantly affected the light environ-ment within the forest,with total radiation under the canopy at densities of 833,2500,and 6667 trees/hm^(2) being 77.82,31.94,and 14.03μmol/(m^(2)·s),respectively,and total illuminance in the understory being 5893.13,1130.7,and 761.5 Lx,respectively.The Shannon-Wiener index and Pielou's evenness index of the herb layer showed an initial increase followed by a decrease with increasing density;the Simpson's dominance index and Pielou's even-ness index of the shrub layer decreased with increasing afforestation density.As density increased,the biomass of C.lanceolata fine roots and the C.lanceolata root competition index both gradually increased,while the biomass of understory vegetation and its root competition index gradually decreased.Light environment indicators were significantly positively correlated with the Pielou's evenness index of the shrub layer and the Simpson's domin-ance index of the herb layer,significantly negatively correlated with the C.lanceolata root competition index,and showed a highly significant positive correlation with the root competition of understory vegetation.From this,changes in afforestation density significantly affect the forest's light environment,with light-related indicators de-creasing as afforestation density increases,leading to a reduction in the biomass of understory vegetation in C.lanceolata saplings and affecting the diversity changes of understory vegetation,as well as enhancing the root competition ability of C.lanceolata.Considering the growth condition of C.lanceolata,an afforestation density of 2500 trees/hm2 is deemed more suitable for constru

关 键 词：杉木 造林密度 林下光环境 细根竞争 植被 

分 类 号：S725[农业科学—林木遗传育种]