【摘要】 目的 为建立可供法医学实战的黄河干流甘肃段硅藻种属分布数据库，课题组于2024年秋季（9月）与2025年春季（4月）对该河段进行了两次系统的采样调查。方法 采用微波消解-真空抽滤法处理样品，依托扫描电子显微镜进行识别。沿河道自上游玛曲至下游黑山峡，共布设12个代表性采样断面。结果 两次调查累计检出硅藻24属53种（含变种），常见优势类群为舟形藻属（Navicula）、菱形藻属（Nitzschia）、针杆藻属（Synedra）和脆杆藻属（Fragilaria）。结论 研究发现，硅藻种属组成存在明确的空间梯度与显著的季节性差异。空间上，上游河段物种相对丰富，脆杆藻属等清水型种类常见；中下游河段，耐性较强的梅尼小环藻（Cyclotella meneghiniana）和偏缝菱形藻（Nitzschia palea）等比例上升。季节上，春季（低温期）以脆杆藻属为优势特征，而秋季（高温期）则转变为以菱形藻属和舟形藻属为优势。本文为后续深入研究其动态规律及生态驱动机制提供了基础数据。更多还原

【Abstract】 Objective To establish a forensic practice-oriented database of diatom species distribution in the Gansu section of the main stream of the Yellow River, this study conducted two systematic sampling surveys in the autumn of 2024(September) and the spring of 2025(April). Methods Samples were processed using the microwave digestion-vacuum filtration method and identified via scanning electron microscopy. Twelve representative sampling sections were established along the river from the upstream Maqu to the downstream Heishanxia. Results A total of 53 species(including varieties) belonging to 24 genera were detected in the two surveys, with common dominant groups including Navicula, Nitzschia, Synedra, and Fragilaria. Conclusion The study revealed clear spatial gradients and significant seasonal differences in diatom species composition. Spatially, the upstream section exhibited relatively higher species richness, with clean-water species such as Fragilaria being common, while the mid-to downstream sections showed an increase in more tolerant species like Cyclotella meneghiniana and Nitzschia palea. Seasonally, Fragilaria was dominant during the spring(low-temperature period), whereas Nitzschia and Navicula became dominant in the autumn(high-temperature period). This study provides foundational data for further research on their dynamic patterns and ecological driving mechanisms.更多还原