Biodiversity conservation and sustainable forest management are becoming increasingly challenging under rapid and complex global environmental change. This book adopts a transhemispheric and transdisciplinary perspective to compare temperate forests in the Southern and Northern Hemispheres. By analysing key bioclimatic gradients, notably the trans-Andean productivity and drought gradient in Northern Patagonia and gradients within Central European beech forests, we address questions of common ancestry and divergent evolution, ecological adaptation, climatic niche differentiation, and ecosystem dynamics that are central to understanding temperate forest responses to climate change. The structural approach presented emphasises the need for long-term collaboration and international networks to implement nature-based solutions, aligned with the UN 2030 Agenda and Sustainable Development Goal 17.