Carbon (C) and silicon (Si) are essential lake ecosystem components, impacting both phytoplankton growth and other available elements and nutrients. In this study, we selected a typical floodplain-lake system to explore the seasonal role of coupled C and Si as matter is imported and exported through lotic water processes. Results showed considerably higher dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and dissolved total carbon (DTC) concentrations during the transitional stage between the dry and wet season (here referred to as TDW) compared to the other seasonal stages (5.81 mg/L–28.80 mg/L), indicating that imported runoff significantly effects the transport of C and Si. Rock weathering was the main source of dissolved silicon (DSi). The dilution effect and water temperature may also impact DIC, DOC, and DTC concentrations. Except for the wet season, Bacillariophyta was the dominant phytoplankton taxon, and diatom growth as well as the growth of other algae taxon may influence DSi and DTC concentrations through several biochemical processes. This study describes effects of coupled C and Si and highlights variation in environmental variables driven by the resident phytoplankton communities in a lake ecosystem.

碳 (C) 和硅 (Si) 是湖泊生态系统的重要组成部分，影响浮游植物的生长以及其他可用元素和养分。在本研究中，我们选择了一个典型的洪泛区-湖泊系统来探索 C 和 Si 耦合的季节性作用，因为物质通过水流过程进出。结果表明，与其他季节相比，在旱季和雨季之间的过渡阶段（此处称为 TDW），溶解的无机碳 (DIC)、溶解的有机碳 (DOC) 和溶解的总碳 (DTC) 浓度要高得多。 5.81 mg/L–28.80 mg/L)，说明输入径流对 C 和 Si 的迁移影响显着。岩石风化是溶解硅（DSi）的主要来源。稀释效应和水温也可能影响 DIC、DOC 和 DTC 浓度。除雨季外，Bacillariophyta 是主要的浮游植物分类群，硅藻生长以及其他藻类分类群的生长可能通过几个生化过程影响 DSi 和 DTC 浓度。本研究描述了耦合 C 和 Si 的影响，并强调了由湖泊生态系统中常驻浮游植物群落驱动的环境变量的变化。