The aim of the current study was to assess the biochemical methane potential (BMP) of different functional groups harvested from different semi-natural grassland types that are valuable for nature conservation purposes. Ensiling of particular biomass did not significantly influence its methane yield, however, the ranking of functional groups by their methane yield varied during the experiment. During the first days of the experiment, methane was released most rapidly by legumes and other forbs with higher N and P contents. At the end of the BMP experiment the quantity of methane produced was higher in grasses and sedges/rushes with lower K, Mg and lignin content. Hence, measurement of feedstock chemical composition is an essential input to develop suitable technology for anaerobic digestion of late harvested biomass from semi-natural grasslands. (C) 2014 Elsevier Ltd. All rights reserved.