云贵高原富营养化湖泊优势沉水植物维持机制的化学计量内稳性研究

湖泊营养化进程导致水生植被尤其是沉水植被严重退化，高原湖泊也未能幸免，因此弄清营养化湖泊沉水植被的退化机理和优势沉水植物的维持机制，就成为我国富营养化湖泊沉水植被成功恢复的首要任务。基于此，本项目拟在前期沉水植被退化机理研究的基础上，围绕"化学计量内稳性高是富营养化湖泊现存优势沉水植物的维持机制"假设，以云贵高原湖泊和围隔生态系统为研究对象，将野外调查与控制实验相结合，运用生态化学计量学理论，阐释生态系统内C、N、P元素生态过程的改变(富营养化)对沉水植物的生活史、种群动态、群落结构的影响，明确不同营养水平下优势沉水植物的化学计量内稳性特征，揭示化学计量内稳性在富营养化湖泊优势沉水植物维持机制中的作用；并将高原与长江中下游富营养化湖泊中沉水植物的生态化学计量特征进行比较研究，探讨不同区域富营养化湖泊沉水植物的维持机制与恢复策略的异同。

Eutrophication has caused serious degradation of aquatic plants, especially submerged macrophytes, in Yangtze River floodplain lakes besides plateau lakes. Therefore, degradation and maintenance mechanisms of submerged macrophytes has been becoming an urgent task of lake restoration at present. Ecological stoichiometry is a useful concept with which to explore organisms' life forms and ecosystem structure and function in relation to the elemental ratios (stoichiometry) of environment (water, soil) and organisms. Stoichiometric homoeostasis is the ability of an organism to maintain a given elemental composition despite variation in the elemental composition of its environment or diet and re?ects the net outcome of many underlying physiological and biochemical adjustments as organisms respond to their surroundings. It is fundamental for establishment of ecological stoichiometry. Ecosystems are controlled by non-equilibrium flows of both materials (nutrients) and energy (carbon). Environmental stoichiometry can strongly affects an organism's stoichiometry, which may alter competitiveness of a species, leading to a shift of species composition. In the applying project, we want to explore whether/how environmental stoichiometry (eutrophication) change the stoichiometric homeostasis of submerged macrophytes in different eutrophic lakes of Yunnan-Guizhou plateau using the methods of comparative limnology and experimental limnology. The aim is to test the hypothesis that dominant submerged macrophyte has higher stoichiometric homeostasis with the increase of eutrophication. We also compare the differences in maintenance mechanism and restoration strategy of submerged macrophytes between plateau lakes and floodplain lakes. We hope restore aquatic plants in different eutrophic lakes according to stoichiometric homeostasis in order to gain biodiversity.