Hazard assessment of spontaneous plants based on plant diversity: A case study of the Jiahu Archaeological Site, China

This study fills a long-standing research gap in systematic vegetation hazard assessment for Chinese archaeological sites, a field previously dominated by Mediterranean-focused cases. Taking the Jiahu Archaeological Site in Henan as the research object, it explores the correlation between spontaneous plant diversity and heritage fabric risks to support targeted site vegetation conservation. In July to August 2025, 54 sampling plots (162 quadrats in total) were deployed for field vegetation investigation. By integrating the Hazard Index (HI) and Deteriogenic Index (DI), the study evaluated the potential risks of plants and vegetation communities. A total of 139 spontaneous herbaceous plant species across 114 genera and 44 families were recorded, dominated by Asteraceae, Poaceae and Amaranthaceae, with therophytes and native species as the main components. The flora shows distinct East Asian features, and some of its floristic components possess high ornamental value. Within the 8 cluster groups, group D3 has a significantly higher Margalef index.Thirteen hazardous species were screened out, with Rumex crispus , Alternanthera philoxeroides , and Humulus scandens identified as core risk sources. The shrub community dominated by Cirsium arvense var. integrifolium and Broussonetia papyrifera showed the highest HI ( p < 0.01) and DI ( p < 0.001), while the Setaria viridis grassland had the lowest risk. This study clarifies the differentiation pattern of plant diversity and its hazard risks at Jiahu Site, provides a scientific basis for dynamic vegetation monitoring and precise management of the site, and enriches East Asian case evidence for the global archaeological vegetation conservation assessment system.