The targets of the UN Convention on Biological Diversity (CBD) explicitly call for preservation and restoration of forest biodiversity and ecosystem integrity. Guidance on how tree diversity should be managed to restore ecosystems and mitigate climate change is urgently needed. The rapid increase in the establishment and analysis of forest biodiversity experiments over the past two decades provides a basis for insights on how to manage global forests to achieve the CBD targets. This session aims to advance the understanding of consequences of tree diversity for ecosystem resilience and climate mitigation using these experiments. We encourage contributions on deciphering resilience mechanisms as well as promoting biodiversity-positive climate solutions. Contributions could consider different aspects of biodiversity effects regarding climate mitigation (e.g., carbon storage, temperature buffering) and adaptation (e.g., stability, resistance, resilience), approaches to measure these (e.g., remote sensing, genetic approaches to detecting adaptation), and discussion of potential mechanisms. We also welcome submissions on how to design experiments for the future to co-benefit climate mitigation actions and biodiversity conservation from researchers across continents, climate zones and different research backgrounds.