Association (ecology)
In phytosociology and community ecology, an association is a ecological community characterized by a definite species composition, a consistent physiognomy, and occurrence under similar habitat conditions. Although the concept has its roots in Alexander von Humboldt's early plant geography, its modern phytosociological definition was developed by Charles Flahault and Carl Joseph Schröter, formally adopted by the Third International Botanical Congress in 1910, and later became the fundamental unit of Braun-Blanquet vegetation classification.