上海大金山岛常见木本植物功能性状对生长和死亡的影响

Functional traits influence the growth and mortality of common woody plants in Dajinshan Island,Shanghai,China

揭示功能性状如何影响关键植物种群特征有助于深化对群落动态的理解。该研究基于上海大金山岛26种常见木本植物5年期(2016-2021年)生长死亡动态的监测数据,通过测量各物种与光、水和养分资源竞争与利用策略相关的9个叶片和木质性状,分析了不同功能性状单独及其综合形成的植物经济谱与物种相对生长率和死亡率的关系。结果显示:叶面积和叶片氮含量与物种相对生长率显著正相关,叶片厚度、小枝密度和叶干物质含量与相对生长率显著负相关。干材密度和小枝密度与物种相对死亡率显著负相关。由9个功能性状构成的植物经济谱可解释物种相对生长率32.8%的变异,但是与相对死亡率无显著相关关系;资源获取型物种比保守型物种具有更高的相对生长率。以上结果表明,植物功能性状是影响植物生长的重要因素,植物经济谱可较准确地预测物种间相对生长率的差异,但对物种相对死亡率的预测较弱。

Aims Trait-based methods have provided a new viewpoint for predicting community dynamics.We use these approaches to reveal how functional traits influence the key demographic rates of plant species,thereby improving our understanding of community dynamics.Methods We monitored the growth and mortality rates of 26 common woody plant species from Dajinshan Island,Shanghai,over a five-year period(2016–2021).Nine leaf and wood traits related to competition and utilization strategies for light,water and nutrient resources were measured.Then,the relationships between the relative growth and mortality rates and each of individual trait,as well as the multi-trait synthesized plant economics spectrum,were analyzed.Important findings Our results showed that leaf area and leaf nitrogen content were significantly and positively correlated with the relative growth rate,while leaf thickness,twig wood density and leaf dry matter content were significantly and negatively correlated with the relative growth rate.Stem wood density and twig wood density were significantly negatively correlated with the relative mortality rate.The plant economics spectrum that is formulated by nine traits,could explain 32.8% variation in relative growth rate;however,it did not correlate with the relative mortality rate.The relative growth was higher for acquisitive species than that for conservative species.Our results suggest that plant functional traits are important in affecting their growth,and that plant economics spectrum can accurately predict variations in relative growth rates among species,but its predictions for relative mortality are weaker.