It remains challenging to describe ecosystem services (ES) provided by grassland diversity and their underlying drivers.Issues for characterising them are related to scale, knowledge and outcomes that are stakeholder-dependent. Forage production interests farmers, while C sequestration, species richness and the landscape mosaic interest society. To address these issues, we developed a methodological framework (MF) based on five grass functional types (GFTs) which enables usable indicators to be easily defined, such as the percentage of plants with a fast (FastGFT) growth strategy in grasslands. The MF consists of characterising plant functional diversity at field and farm levels, analysing its response to environmental and management drivers, and its effects on ES. The MF is applied to eight farms differing in their orientation and in their management intensity. FastGFT responds positively to the amount of fertiliser supplied and negatively to field elevation. At the field level, FastGFT is positively correlated with herbage production and negatively with soil C content and species richness. Within-farm grassland diversity of FastGFT allows examination of how animal feed requirements match available resources and the landscape mosaic created. Our MF addresses grassland diversity with indicators derived from GFT, which allows summarising relations between environmental and management drivers and ES, then examines trade-offs between ES.