Fluvial silicon (Si) plays a critical role in controlling primary production, water quality, and carbon sequestration through supporting freshwater and marine diatom communities. Geological, biogeochemical, and hydrological processes, as well as climate and land use, dictate the amount of Si exported by streams. Understanding Si regimes—the seasonal patterns of Si concentrations—can help identify processes driving Si export. We analyzed Si concentrations from over 200 stream sites across the Northern Hemisphere to establish distinct Si regimes and evaluated how often sites moved among regimes over their period of record. We observed five distinct regimes across diverse stream sites, with nearly 60% of sites exhibiting multiple regime types over time. Our results indicate greater spatial and interannual variability in Si seasonality than previously recognized and highlight the need to characterize the watershed and climate variables that affect Si cycling across diverse ecosystems.

中文翻译：

---

建立北半球河流硅体系及其稳定性

河流硅 (Si) 通过支持淡水和海洋硅藻群落，在控制初级生产、水质和碳封存方面发挥着关键作用。地质、生物地球化学和水文过程以及气候和土地利用决定了溪流输出的硅量。了解硅状态（硅浓度的季节性模式）可以帮助识别驱动硅出口的过程。我们分析了北半球 200 多个河流站点的 Si 浓度，以建立不同的 Si 状态，并评估了站点在记录期间在不同状态之间移动的频率。我们在不同的流站点观察到五种不同的状态，近 60% 的站点随着时间的推移表现出多种状态类型。我们的结果表明，硅季节性的空间和年际变化比之前认识的更大，并强调需要描述影响不同生态系统硅循环的流域和气候变量的特征。