Diversity and Ecological Factors Influencing Medicinal Plant Use Among Ethnolinguistic Groups in the Philippines

ABSTRACT Many human populations rely on natural remedies for health and healing, with traditional medicinal plants playing a vital role in diverse ethnolinguistic cultures and contributing to biodiversity conservation. Research and conservation efforts to integrate traditional knowledge into healthcare are vital for preserving this heritage and for promoting sustainable healthcare in the Philippines. However, many of these systems are increasingly threatened by rapid environmental changes. In this study, we performed a nationwide synthesis to understand the diversity, distribution, and relationship of traditional plant use among various ethnolinguistic groups. We identified at least 796 plant species from 160 families and 65 orders that were utilised by 34 ethnolinguistic groups to treat 25 disease types. Our findings revealed a strong relationship between linguistically similar groups, indicating that geographical proximity, linguistic background, shared cultural practices, and environmental factors collectively influence medicinal plant use patterns among different groups. Furthermore, we developed the Species Use Priority Importance (SUPRIM) indicator to assess the priority level of plant species based on their use among ethnolinguistic groups and disease types. Factors such as the availability of healthcare facilities, proximity to roads, educational facilities, and tree density were significantly associated with higher SUPRIM indicator values. We posit that, despite modernisation and rapid development in the Philippines, the relationship between Indigenous Peoples and their environment continues to shape the value of medicinal plant species within communities. Our findings further highlight the need for conservation efforts in indigenous lands that prioritise cultural protection and integrate ecological sustainability.