Forests and trees are critical for the survival of life on earth. They conserve a tremendous biodiversity and fulfill essential ecosystem services such as climate regulation, cycling of nutrients and water. They contribute to food and nutrition security, are a major source of raw materials and offer countless livelihood opportunities. However, forests and trees are increasingly threatened by anthropogenic pressures such as overexploitation and land conversion, which are intensified by climate change. At the same time countless tree species and their forest genetic resources (FGR) with exceptional potential uses for supporting the global transition to low carbon food systems and the UN decade on Ecological Restoration are badly conserved and remain critically underutilized. For the last 10 years, the FTA program has set in place research activities that focused on understanding pressures on and threats to populations of socio-economically important tree species; formulating effective, efficient and equitable safeguards for tree genetic resources that are adapted to the local context and species characteristics; and promoting conservation and characterization of germplasm of high-value tree species from forests to farms. FTA has also conducted a range of ecosystem- and landscape-level research projects that explored how silvicultural and monitoring practices can support sustainable timber production while ensuring delivery of multiple ecosystem services, including biodiversity conservation, carbon storage, livelihood support and nutrition security from forest foods. Much of the program’s later work focused on multiple-use forest management. This review of the program’s most salient experiences — derived from a decade of collaborative research — presents a portfolio of the most promising solutions and the significant contributions that FTA has provided to global conservation and sustainable use of tree biodiversity. These achievements also contribute to the international policy arena, particularly to the strategic objectives of various conventions (the Convention on Biological Diversity, United Nations Framework Convention on Climate Change, United Nations Convention to Combat Desertification), and to the efforts led by the Food and Agriculture Organization (FAO) to develop a global conservation strategy for forest genetic resources.