Ethnomedicinal value of karst paddy weeds: insights from Zhuang communities in Jingxi, China.

backgroundIn rice paddy ecosystems, weeds have long been regarded as harmful organisms that restrict crop yields. Traditional management models rely heavily on chemical herbicides, which have triggered issues such as soil pollution, biodiversity decline, and disruption of ecological chains, becoming prominent challenges to the sustainable development of modern agriculture. This study is conducted in the Zhuang ethnic settlement area of Jingxi, Guangxi, China. As a typical distribution area of karst landforms and a biodiversity hotspot, this region is rich in ethnic traditional knowledge. It aims to break through the cognitive dichotomy between weeds and resources. The research focuses on the traditional utilization practices of paddy field weeds by local Zhuang people, with an emphasis on exploring their ethnic medicinal value. The aim of this study is to supplement the deficiencies of existing pharmacopoeias in the inclusion of ethnic medicinal plants, while providing a scientific basis and practical reference for exploring resource utilization-based sustainable management strategies for paddy field weeds.

methodsEthnobotanical survey methods (snowball sampling, semi-structured interviews, and participatory rural appraisal) were adopted to interview 160 local herbalists and villagers who provided informed consent. Simultaneously, plant specimens from field ridges were collected and identified, and the reliability of Traditional Ecological Knowledge (TEK) was ensured through cross-validation. Quantitative ethnobotanical indices, including Relative Importance (RI), Informant Consensus Factor (FIC), Fidelity Level (FL), and Economic Value Index (EV), were applied to validate TEK.

resultsA total of 154 weed species with ethnic medicinal value in Jingxi's paddy field ecosystem were recorded, belonging to 60 families, with Asteraceae and Poaceae as the dominant families. One hundred and twenty-eight species (83.1%) were not included in the Chinese Pharmacopoeia, and 19 already included species showed significant differences in traditional efficacy compared with pharmacopoeia records. High-consensus uses (FIC ≥ 0.94) included tonsillitis, pancreatitis, and hair darkening. The significant medicinal properties presented by invasive species such as Bidens pilosa and Ageratum houstonianum provide pivotal empirical evidence for the resource-oriented management of invasive species. TEK was highly concentrated in the elderly group (43.13% aged 61-70), while cognitive gaps among the younger generation and excessive herbicide use posed dual threats to knowledge inheritance.

conclusionThis study is the first to systematically reveal that paddy field weeds in Jingxi are an underdeveloped treasure trove of ethnic medicinal resources. The strategy of "utilization-based prevention, control, and conservation" not only provides a scientific basis for the sustainable management of weeds but also offers crucial support for supplementing medicinal resources, protecting biocultural diversity, and preserving traditional ecological knowledge.