Natural, semi-natural, and temporary grasslands harbour tremendous plant diversity. In this study, we identified various functional categories of plants to better characterise their levels of forage production and ecosystem services. The categories were defined based on species' growth rates (fast or slow) and timing (growth concentrated in the spring or more spread out over the year). A review of the literature showed that the functional composition of plant communities influences forage production (level and timing), carbon sequestration, and pollination. We developed indices that can be used to characterise functional composition; they can be calculated using simple plant survey data.