南京林业大学学报（自然科学版）2024，Vol.48Issue(5)：28-38,11.
雅长保护区老龄林不同林层功能性状多样性及其影响因素分析
Affecting factors analysis of functional diversity at different forest strata in an old growth forest community in Yachang Natural Reserve
摘要
Abstract
[Objective]Functional diversity is crucial for forest biodiversity protection and maintenance of ecosystem stability.Exploring the characteristics and causes of functional diversity variation at different stratum levels will assist in understanding the maintenance mechanisms of biodiversity and plant community assembly processes.[Method]Leaf traits and environmental factors were collected from forest plot data from an 1.6 hm2 evergreen broadleaved forest in Guangxi Yachang Orchidaceae National Natural Reserve.K-means partitioning and Gaussian kernel density estimation were used for stratification.The direct and indirect effects of species diversity and environmental factors(light,topography,and soil)on functional diversity were explored in different forest strata using structural equation models.[Result]The diversity indices of the understory were greater than those of the canopy(P＜0.05).Species diversity had a significant direct impact on all four functional diversity indices in the understory layer,whereas only the functional richness index(FRic)and quadratic entropy(RAOQ)indices were affected directly by species diversity in the canopy layer(P＜0.05).A significant indirect effect(β=0.278,P＜0.01)of canopy openness on FRic index and a direct effect(β=-0.593,P＜0.01)of canopy openness on functional evenness index(FEve)were found for understory trees.Topographic factors affected canopy functional diversity.Specifically,there was a relatively significant direct effect of aspect on FEve(β=-0.420,P＜0.01)and RAOQ(β=-0.300,P＜0.05)indices for canopy trees.Soil factors mainly affected the functional diversity of different forest layers through species diversity.Soil total phosphorus,available phosphorus,alkaline hydrolysis nitrogen,and available potassium content had a greater effect on the functional diversity of the understory,whereas soil total potassium content affected the FRic and RAOQ indices of the canopy.[Conclusion]There were marked differences in the characteristics of functional diversity at different forest stratum in the study area.Functional diversity was mainly affected by species diversity,canopy openness,and soil nutrients of understory plants,whereas topographic factors determined the functional diversity of the canopy layer.This study reveals the effects of biological and abiotic environmental factors on functional diversity across different forest layers and expands the understanding of the diversity of vertical stratification.The findings provide a further reference for biodiversity protection in natural forests.关键词
老龄林/林冠层/林下层/功能性状多样性/结构方程模型(SEM)Key words
old-growth forest/canopy/understory/functional diversity/structural equation model(SEM)分类
农业科技引用本文复制引用
王耀仪,王宏翔,王永强,曾文豪,叶绍明..雅长保护区老龄林不同林层功能性状多样性及其影响因素分析[J].南京林业大学学报（自然科学版）,2024,48(5):28-38,11.基金项目
广西科技基地和人才专项(AD20297051) （AD20297051）
国家自然科学基金项目(32101520). （32101520）
