The Amazon region, Earth's most important ecosystem, is home to more than 400 Indigenous groups that use thousands of rainforest plant species. They pass on their knowledge of the flora primarily through oral tradition, usually from parents or other family members to their children. This creates a "living library of knowledge" about how to use native plants. Until now, little was known about how this treasure trove of knowledge is affected by the combined effects of climate change and language loss. A new study by the University of Zurich (UZH) provides the first reliable scientific data on the impact of global change on the biocultural heritage of the Amazon region.