Species Specific Division Rates of Diatoms: Response to Changes in Dissolved Silicate Concentrations

确定自然种群中物种的特定生长率是浮游植物生态学中最受欢迎的测量方法之一。这项研究计划将使用荧光染料(罗丹明123)调查硅藻生长速度对溶解硅酸盐供应中扰动的响应。在罗丹明123中孵育的硅藻积极地将其积累到二氧化硅沉积小泡中，罗丹明123与二氧化硅共沉积。由此产生的瓣膜和带状带变得荧光，并为硅藻的细胞分裂提供了一个标记；因此，可以估计物种特定的生长率。将进行实验，以研究低浓度溶解硅酸盐可能限制溶解硅酸盐的吸收和限制硅藻生长速度，最终影响物种演替的环境溶解硅酸盐供应速率的变化。区分吸收限制和生长速度限制的能力对于我们理解水生系统中的营养限制是至关重要的。此外，还将进行实验，以探讨硅藻生长速度可能是影响浮游植物产量对新营养物质输入的关键因素。

The determination of species specific growth rates in natural populations is one of the most sought after measurements in phytoplankton ecology. This research program will investigate the response of diatom growth rates to perturbations in dissolved silicate supplies using a fluorescent dye (Rhodamine 123). Diatoms incubated in Rhodamine 123 actively accumulate it into the silica deposition vesicle and Rhodamine 123 is co- deposited with silica. The resulting valves and girdle bands become fluorescent and provides a marker for cell division in diatoms; thus allowing for the estimation of species specific growth rates. Experiments will be performed to investigate the potential of low dissolved silicate concentrations to limit the uptake of dissolved silicate and to limit diatom growth rates, ultimately influencing species succession with changes in ambient dissolved silica supply rates. The ability to distinguish between the limitation of uptake and the limitation of growth rate is critical to our understanding of nutrient limitation in aquatic systems. In addition, experiments will be performed to investigate the response of diatom growth rate may be a key factor governing the phytoplankton production to new nutrient input.