are defined as morpho-physiophenological traits which impact fitness indirectly via their effects on growth, reproduction and survival. Notice that is definition is not specific to species. Since larger biological organizations grow, reproduce and sustain just as individual organisms do, functional traits can be used to describe ecosystem processes and properties as well. To distinguish between functional traits at different scales, the classification scheme adopts the following nomenclature. Individual organisms have Ecophysiological traits and life-history traits; populations have demographic traits; communities have response traits; and ecosystems have effect traits. At each level, functional traits can directly and indirectly influence functional traits in the levels above or below them. For example, when averaged over an ecosystem, individual plants' heights can contribute to ecosystem productivity or efficiency.
zdroj: wikipedie, podle Viole 2007 Let the concept of the trait be functional!