Functional groups

A functional group is a group of species (for example, tree species) that have similar functional traits. To define a functional group, one has to choose what functional traits to take into account, and then to choose the threshold of difference between groups, or the number of groups to create. As such, functional groups are very contextual as to what we chose to define them; but they can be really useful to asses the functional diversity of forests, or to make things simpler when we want to summarize data.