Diversity and use of medicinal plants for soup making in traditional diets of the Hakka in West Fujian, China

Background Wild edible and medicinal plants were an important component of traditional diets and continue to contribute to food security, nutrition, and health in many communities globally. For example, the preparation and consumption of soup made of medicinal plants for promoting health and preventing disease are a key component of the traditional diets of the Hakka socio-linguistic group of China's West Fujian Province. As environmental and socio-economic factors drive the shift away from traditional diets, there is a need for ethnobotanical documentation of the diversity of wild edible and medicinal plants as well as associated knowledge and practices. Method Ethnobotanical surveys were conducted in Hakka communities in West Fujian Province between 2017 and 2018 to document plants used in medicinal soups as well as associated traditional ecological knowledge, practices, and conservation status. Surveys included semi-structural interviews, key informant interviews, participatory rural appraisal, and focus group discussions. Quantitative indices, including cultural food significance index (CFSI) and relative frequency of citation (RFC), were calculated to evaluate the importance of documented plants to Hakka communities. The species with the highest CFSI and RFC values were ranked by informants and further evaluated according to their individual properties and growth environment. Results A total of 42 medicinal plant species, belonging to 25 families and 41 genera, were documented for making soup by the Hakka. The Asteraceae botanical family was the most prevalent, and their root or the entire plant is used for soup making. Informants incorporate different ingredients in soups for their flavors as well as medicinal properties on the basis of the local ethnonutrition system. The most prevalent medicinal uses of the documented plants for making soups were used for clearing inner heat (58.1% of the species), treating inflammation (37.2%), and counteracting cold in the body (20.9%). Informants perceived that the medicinal properties of soup-making plants are influenced by the time of harvest, the local environment, and the climate. Conclusion Efforts are needed to preserve the ecological knowledge associated with traditional diets towards supporting both environmental and human well-being in rapidly developing communities experiencing the nutrition transition and biodiversity loss.