As  a key part of actions to reach net zero carbon emissions by 2050, the UK Government set a target of up to 19% woodland cover. Key decisions therefore are required concerning how and where we expand tree cover.  Modern  forestry has generally been based on even-aged monocultures largely  because of  timber production. However, future forests will play a key role in  climate change mitigation. It is  therefore crucial that appropriate  informed decisions are made with regard to the structure, composition  and planning of future forests, in  order to provide sustainable solutions that provide environmental, economic, and health benefits to society. Genetically diverse, mixed, and irregular forests with their higher biodiversity and  niche complementarity, are promising new forest configurations for  regulating the water cycle, storing carbon, and delivering other goods and services.