武夷山不同海拔杜鹃和黄山松叶片功能性状的变化

Altitudinal variations of leaf functional traits of Rhododendron simsii and Pinus taiwanensis in Wuyi Mountain,Jiangxi

研究不同海拔生境下同种植物叶片功能性状的变化,有望揭示植物对环境变化的潜在适应策略,为预测气候变化下植物物种分布、群落动态和森林生态系统结构功能的变化提供依据。本研究以江西武夷山3个海拔(>1900,1500~1700,1000~1300 m)生长的2个共有树种杜鹃(Rhododendron simsii)和黄山松(Pinus taiwanensis)为对象,分析了与防御(脂质、木质素、水溶性酚、有机酸、非结构性碳水化合物、结构性碳水化合物含量)和生长(比叶面积、蛋白质、矿物质、碳(C)、氮(N)、磷(P)含量和N/P)相关的功能性状、叶片构建成本及其之间的相关性。结果表明:2个树种叶片构建成本在不同海拔生境间差异不显著;2个树种叶片水溶性酚含量均随海拔升高显著降低,蛋白质、N和P含量则显著增加;随海拔升高,杜鹃叶片木质素含量显著降低,结构性碳水化合物和矿物质含量显著增加,而黄山松针叶的非结构性碳水化合物含量则显著增加;杜鹃叶片构建成本与有机酸、矿物质含量和比叶面积呈显著负相关,与非结构性碳水化合物呈显著正相关;黄山松叶片构建成本仅与水溶性酚含量呈显著正相关;杜鹃叶片蛋白质与结构性碳水化合物、黄山松针叶蛋白质与非结构性碳水化合物呈显著正相关。杜鹃和黄山松都能通过调节与生长和防御相关的叶片功能性状来响应生境的变化,对环境变化具有一定的适应能力。

Understanding the variation of leaf functional traits of plant species from different elevations provides basis for assessing the adaptive strategies of plants and predicting the potential shifts in plant species distribution,community dynamic,and forest ecosystem structure and function under climate changes.In this study,we quantified the variations in leaf traits of two species(Rhododendron simsii and Pinus taiwanensis)commonly growing at three elevations(>1900,1500-1700,1000-1300 m above sea level)in Wuyi Mountain National Nature Reserve in Jiangxi Province.Leaf traits related to defence(i.e.,concentrations of lipids,lignin,soluble phenolics,organic acids,total non-structural carbohydrates,total structural carbohydrates),traits related to growth(i.e.,specific leaf area,concentrations of protein,minerals,carbon(C),nitrogen(N),phosphorus(P),and N/P ratio),and leaf construction costs(CC)were compared for species from different elevations.Correlations among the different leaf traits were also examined.The results showed that leaf CC of both species did not vary significantly among the elevations.The concentrations of soluble phenolics in leaves of both species significantly decreased with elevation,while foliar protein,N and P concentrations increased.With increasing elevation,lignin concentrations in leaves of R.simsii decreased,whereas the concentrations of total structural carbohydrates and minerals in leaves of R.simsi and the concentration of total non-structural carbohydrates in leaves of P.taiwanensis increased.Leaf CC of R.simsii was negatively correlated with the concentrations of organic acids and minerals and specific leaf area,and positively correlated with the concentration of total non-structural carbohydrates.Leaf CC of P.taiwanensis was positively correlated with the concentration of soluble phenolics.The concentration of leaf protein was positively correlated with the concentration of leaf total structural carbohydrates in R.simsii,and positively correlated with the concentration of leaf non-structural carbohydrates in P.taiwanensis.The variations of leaf functional traits related to growth and defence across the altitudinal gradient indicate that both species could adapt to environmental change.