Phytocoenosis

phytocoenosis

[¦fīd·ō·sē′nō·səs]
(ecology)
The entire plant population of a particular habitat.

Phytocoenosis

 

(also plant community), the aggregate of vegetable organisms within a relatively homogeneous area. The plants of a phytocoenosis display complex interrelations with other plants, with animals, and with the environment. Each phytocoenosis is a system with a definite composition (consisting as a rule of many ecologically and biologically different species) and a definite structure. The composition and structure of phytocoenoses evolve as a result of the natural selection of plant species capable of coexisting with each other and with animals in certain environmental conditions, and in many instances as a result of the influence of man.

The plants that constitute a phytocoenosis alter their environment in the process of their vital activity, although different groups of plant species (phytocoenotypes) play varying roles. After consuming necessary resources, such as light, water, and minerals, they secrete metabolic wastes into the external environment and leave dead organs in or on the soil, thus leading to the formation of a special phytoclimate. Each phytocoenosis is characterized by specific environmental factors.

The phytocoenosis is the most active part of a biocoenosis and biogeocoenosis (ecosystem). It accomplishes photosynthesis (as a result of the vital activity of photosynthesizing organisms) and nitrogen fixation (by nitrogen-fixing microorganisms) and, together with animals, plays an important part in energy conversion and the cycle of matter on earth. Thus, the phytocoenosis is the major producer of organic substances, which it supplies to heterotrophic organisms, including man. A phytocoenosis is a dynamic system that changes from season to season and year to year. Every phytocoenosis is eventually superseded by another; this process is called succession. The study of phytocoenoses is called phytocoenology.

T. A. RABOTNOV

References in periodicals archive ?
Genetics, plant selection, ecology, and agro-economy scientists mainly from Eastern Europe offer 33 chapters outlining theoretical and mathematical approaches to the taxonomy of biological systems and the problem of plant diversity, with attention to theoretical and practical problems of soil and the environmental sustainability of phytocoenosis.
Therefore, the quantitative estimation of the occurrence of a species in the community need not always be decisive for the determination of the phytocoenosis (Rybnicek 1973).
A forest-brushwood + Carex-Sphagnum community was the parent phytocoenosis of the forest-herbaceous peat.
This phytocoenosis was present in the mire in the Late Glacial and Preboreal and could be identified with the shrub-sedge-brown moss associations described by Liss & Berezina (1981) in Western Siberia.
Seasonality of individual Pseudo-nitzschia species and their relationships with physical-chemical variables in the context of the entire planktonic phytocoenosis must be one of the future priorities to allow evaluation of the potential risk of ASP in the study area.
These communities lie within the association Arenario querioidis-Festucetum gredensis, endemic to the Bejarano-Gredense (Sanchez-Mata, 1989; Sardinero, 1994, 2004; Sardinero & Rivas-Martinez, 1999), although also reaching the Altosalmantino (Amich & Bernardos, 2010), integrated within Hieracio castellani-Plantaginion radicatae, an optimum Carpetan phytocoenosis (although also present in the oroiberian and orocantabric areas) like Minuartio-Festucion.
The presence of phytocoenosis belonging to the Taeniathero-Aegilopion geniculatae alliance in central Italy has been supposed in the territory of the Maremma Natural Park, in the Tyrrhenian province, in extremely arid soil conditions (Izco, 1977); it was later indicated for the surroundings of Pescara River springs, in Abruzzi region (Pirone & al, 1997).
The latter is in fact not correlated with nitrogen-rich soils and does not include nitrophilous phytocoenosis (Izco, 1977; Rivas-Martinez, 1977b; Loidi & al,, 1997), while Thero-Brometalia is usually defined as sub-nitrophilous (Loidi & al.
Floristic characterisation: as shown in Figure 3, numerous species differentiate the phytocoenosis corresponding to Group 1 including Aegilops neglecta, Medi cago orbicularis, Crepis zacintha, Medicago rigidula, Carduus pycnocephalus, Bunias erucago, Vicia lutea, Nigella damascena and Pallenis spinosa.