不同立地条件下杉木细根生物量和功能属性的变异特征及其对树木生产力的影响

细根是木本植物吸收水分和养分的重要器官，在不同环境条件下，树木细根通过调整生物量或功能属性来获取资源以适应环境，进而维持或促进树木生长。然而目前对细根生物量和功能属性如何响应土壤养分的变化，进而影响树木生产力的机制仍不清楚。我们前期研究发现不同地区不同气候主导所形成的生境条件对杉木人工林细根生物量、功能属性以及人工林生物量均有显著影响。然而这种综合生境条件的研究并不能区分以土壤养分为主导的立地条件对细根的影响。本研究拟对同一地区立地指数差异较大的杉木人工林细根生物量、功能属性（菌根侵染率、分枝比、养分吸收速率等）、土壤理化性质（碳、氮、磷及土壤菌丝密度）以及杉木生产力进行分析，结合温室苗木盆栽实验，阐明不同立地条件下杉木细根生物量和功能属性的变异特征，不同功能属性之间的关系以及对杉木生产力的影响。研究结果将对认知植物对环境变化的响应，促进根系生态学的发展，提高森林管理水平具有重要参考意义。

Fine roots are important organs for woody plants to absorb water and nutrients, and their functional properties play a decisive role in tree growth. Under different environmental conditions, fine roots of trees acquire resources to adapt to the environment by adjusting biomass or functional traits, thus maintaining or affecting productivity. However, it is still unclear how fine root biomass and functional traits respond to changes in soil nutrients, thereby affecting tree productivity. Our previous studies have found that different climate-dominated conditions have significant effects on fine-root biomass, functional traits and productivity of Chinese fir plantations. However, these climate zonal conditions cannot determine the effect of site conditions dominated by soil nutrients on fine roots. Thus this project intends to analyze the biomass and functional traits (mycorrhizal colonization, branch ratio and nutrient uptake rate) of fine roots, soil physical and chemical properties (total nitrogen, total phosphorus and soil fungal density), and productivity of Chinese fir (Cunninghamia lanceolata) with different site indices using combination of field investigation with greenhouse nutrient controlling experiments. Our purposes are to quantify the possible relationship between the biomass and functional traits of fine roots, the interrelationship among functional traits and their effects on tree productivity. The results of this study will be of great significance for understanding the responses of plants to environmental changes, promoting the development of root ecology and improving sustainable forest management.