庄里水库硅藻的时空分布特征及其法医学意义

Spatiotemporal distribution of diatoms in Zhuangli Reservoir and its forensic significance

摘要

目的 探究庄里水库硅藻群落的区域性与季节性差异,为溺死鉴定与落水地点分析提供参考依据。方法 选择东、南、西、北四岸为采样点,分别于秋、冬、春季取表层0.5 m水样。采用微波消解-真空抽滤-扫描电镜方法检测硅藻含量与种类,并以Sorensen相似系数(SSC)与弦平方距离(SCD)评价群落相似性与差异性。结果 共检出15种硅藻,各岸与各季的含量存在差异:总体呈冬、春季高于秋季,且多数岸线春季达到峰值,南岸冬季为峰值;常见共有科包括小环藻、菱形藻、直链藻、舟形藻,春季东岸存在波缘藻、布纹藻等指示意义物种。不同季节和岸线间的硅藻群落具有显著的差异性,部分硅藻种类展现出明显的季节性和空间性特异性。结论 硅藻群落的时空分布特征可作为法医学中溺死鉴定和落水地点分析的辅助证据,具有较好的应用前景。

Abstract

Objective To investigate the spatial and seasonal variation of diatom communities in Zhuangli Reservoir and to provide reference data for drowning identification and prediction of putative immersion sites. Methods Surface water samples (0.5 m depth) were collected from four shoreline sites (eastern,southern,western,and northern banks) in autumn,winter,and spring.Diatom abundance and species composition were examined using a microwave-assisted acid digestion-vacuum filtration-scanning electron microscopy (SEM) protocol.Community similarity and dissimilarity among samples were evaluated by the Sorensen similarity coefficient (SSC) and squared chord distance (SCD),respectively. Results A total of 15 diatom species were identified.Diatom abundance differed among seasons and among shorelines,showing an overall pattern of higher counts in winter and spring than in autumn.Most shorelines reached their maximal abundance in spring,whereas the southern bank peaked in winter.Cyclotella,Nitzschia,Aulacoseira,and Navicula species were common to most samples and formed a set of recurrent "core taxa",while the eastern bank in spring harbored taxa with potential indicator value,such as Tabellaria fenestrata and Melosira varians. Conclusion Diatom assemblages in Zhuangli Reservoir exhibit spatial (among shorelines) and temporal (among seasons) structuring.These patterns may serve as useful clues for supporting drowning diagnosis and for comparing environmental concordance between putative immersion sites and organ-derived diatom profiles.

关键词

法医病理学 / 硅藻检验 / 溺死 / 庄里水库

Key words

Forensic pathology / Diatom examination / Drowning / Zhuangli Reservoir

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基金资助

山东省重点研发计划(重大科技创新工程)项目(2021CXGC011305)