Rosaria’s D.Phil research aims to understand the multiple different ecosystem services provided by plant biodiversity in tropical seasonal climate using ethnobotanical study and functional trait data assessment. To then apply this knowledge in the food system resilience planning for local communities in Wallacea and develop a novel methodology for prioritising species conservation based on conservation urgency and ecosystem services. Rosaria will lead a team of over 25 researchers in a field study to Timor, Flores, Sumba, and Sumbawa islands of the Lesser Sunda Archipelago (LSIs), part of Wallacea, Indonesia. LSIs is the only tropical seasonal climate region of Wallacea and unique within SE Asia, comprised of distinctive assemblages of taxa and ecosystem types with high endemicity. Globally, the ES of the seasonally dry forest is poorly known compared to the humid forest. Ethnobotany is the powerful method to understand the provisioning service of the ecosystem in this region due to its many ethnic groups with rich local wisdom in biodiversity use and management. Knowledge about ecosystem service in tropical seasonal climates is not only essential at the global level but also at the local level, where poverty and undernutrition are still a problem due to recurrent dry seasons and poor understanding of biodiversity potential in the area. Doing a field study in four islands in Indonesia, despite its complexity and challenges exacerbated by the pandemic, is made possible by the collaboration between Nusa Cendana and Surya Universities in Indonesia, Royal Botanic Garden Kew, Indonesia Institute of Sciences, and supported by local national parks, botanic gardens, and Governments. Rosaria would also like to thank Prof. Kathy Willis (Oxford), Dr Tim Utteridge and Dr William Milliken (RBG Kew) for their supervision and tremendous support, and the Indonesia Endowment Fund for Education (LPDP) for the D.Phil scholarship.