元江干热河谷植物枝叶功能性状的海拔变异及权衡OA

To investigate the ecological adaptation strategies of dominant plants to altitudes in the Yuanjiang dry-hot valley,this study focused on 13 dominant species(five tree species,six shrub species,and two herb species)across four altitudinal zones in the Yuanjiang National Nature Reserve of Yunnan Province.Six functional traits of current-year twigs were measured,including twig cross-sectional area,volume-based leafing intensity,specific leaf area,leaf dry matter content,blade thickness,and branch length.One-way analysis of variance and principal component analysis were conducted to explore the variations and trade-offs of functional traits among different altitudes.The results revealed that the total variations in the functional traits of branches and leaves of dominant plants across different altitudes ranged from 3.3%to 144.0%.For arbor and shrub species,the twig cross-sectional area,volume-based leafing intensity,and leaf dry matter content exhibited strong variations ranging from 53.5%to 144.0%,while blade thickness showed weak variations ranging from 11.2%to 18.3%.The plant economic spectrum constructed based on principal component 1,which had a high contribution rate,indicated that both arbor and shrub species shifted from acquisition-oriented to conservation-oriented resource utilization strategies as the altitude raised,whereas herb species exhibited the opposite pattern.