Botany - B.Ye. Yakubenko 2017

Part Three. The Plant Kingdom (Plantae)
Chapter XII. Fundamentals of Phytocenology. Concepts of Vegetation
12.2. Morphological and Biotic Characteristics of a Phytocenosis. Species Composition

One of the manifestations of a phytocoenosis's vital activity is the formation and determination of a specific species composition. Each plant community is characterized by a unique species composition that best corresponds to The Nature of its biotic and abiotic interactions. Depending on the participation of species in plant communities, we distinguish dominant and codominant species. The dominants of floodplain meadows are reed canary grass, meadow foxtail, and smooth meadow-grass, accounting for up to 80% or more of the herbage. Codominants have a smaller share in the herbage and share it with the dominants.

Plant species that act as the primary environment-forming agents and determine the nature of a plant community are called edificators or phytocoenosis builders. Species whose role is shared with edificators are called co-edificators. In pine and birch forests, the edificators are pine and birch, whereas in mixed pine-birch forests, pine can act as a co-edificator.

Species that are constantly found in a plant community, but in small quantities, are called asectators. In moist pine forests, the asectator is glossy buckthorn, while in oak forests, it is the wild pear.

Communities dominated by a single species are called monodominant, those dominated by two species are bidominant, and those with three or more are polydominant.

Modern natural vegetation undergoes noticeable changes As a result of human economic activity. For instance, undesirable species such as evening primrose, Canadian fleabane, and black cherry infiltrate coenoses. On the other hand, humans introduce more promising economically valuable species into cultivation—such as jack pine on sandy southern arenas, large-leaved lupine in pine plantation interrows, and Sosnowsky's hogweed under the forest canopy in natural forage forest lands, etc. Plants that grow in phytocoenoses as a consequence of human economic activity are called anthropophytes.