Originating in environments with warmer and drier conditions, non-native tree species can support the adaptation of European forests and urban areas to climate change and therefore, they have the potential to respond positively to the effects of climate change on the Alpine environment. On the other hand, non-native trees involve risks for biodiversity and ecosystem functions, as some are considered invasive and can alter the ecosystem of the area they grow in. The ALPTREES project investigated the opportunities and risks that non-native tree species provide for the future of our urban and forest areas. Furthermore, it developed guidelines for their use and management within the Alpine Space.