This book includes papers presented at the 2021 online meeting of the Fodder Crops and Amenity Grasses Section of EUCARPIA. The theme of the meeting 'Exploiting genetic diversity of forages to fulfil their economic and environmental roles' was presented in four sessions (1) Natural diversity - a valuable source for breeding, (2) Characterizing genetic diversity - the basis for selection, (3) Strategies to optimally exploit genetic diversity and (4) ""Minor"" and ""new"" species - solution for future challenges. Parts I to IV of this book correspond to these four sessions. Part V contains the contributions from the Festulolium Working Group Workshop. The book provides a unique source of information on the most recent results on breeding and research of forage species.