Traditional knowledge of medicinal plants on Gau Island, Fiji: differences between sixteen villages with unique characteristics of cultural value

BACKGROUND: Traditional resource management (TRM) systems develop depending on local conditions, such as climate, culture, and environment. Most studies have focused on the TRM system itself, excluding the people who manage the system, and the relationship between the system and the people. The use of resources and people is intimately linked through the practice of TRM systems on Gau Island and this relationship needs to be understood to advance sustainable resource use. METHODS: A survey was conducted on the use of medicinal plants on Gau Island, Fiji. Interviews were conducted from September 2013 to January 2015 with knowledgeable members of each community. The types of plants, prescriptions, and health problems were documented, and social and ecological factors affecting the sustainability of TRM of medicinal plants used in each of the 16 villages were statistically analysed by linear regression analysis. RESULTS: A total of 58 medicinal plants used on a daily basis to treat 27 health problems were identified on Gau. Two medicinal plants, Botebotekoro (Ageratum conyzoides) and Totodro (Centella asiatica), were used in all districts to treat various health problems. There were contrasts between the villages in the medical lore and prescriptions, and villages often used different traditional treatments than others for the same ailment; therefore, the status and knowledge of medicinal plants have developed distinctly in each village. Geographical and social factors have been suggested as possible reasons for the differences in regional resource utilisation among villages. Statistical analysis of the relationship between the state of TRM and social and ecological factors suggest that community solidarity has a positive impact on the sustainable practice of TRM. This study showed that traditional practices simultaneously contribute to the conservation of the natural environment and the binding of communities. CONCLUSIONS: The results highlight the importance of understanding how TRM systems can contribute to the conservation of the natural environment. Cultural activities are essential to raise community solidarity, which has led to the sustainable use of natural resources. This suggests that merely documenting the use of medicinal plants is not enough to ensure that the skills and knowledge are passed down to the next generation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13002-021-00481-w.