Biocoenosis in the context of "Aquatic ecosystem"

In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization".

Community ecology or synecology is the study of the interactions between species in communities on many spatial and temporal scales, including the distribution, structure, abundance, demography, and interactions of coexisting populations. The primary focus of community ecology is on the interactions between populations as determined by specific genotypic and phenotypic characteristics. It is important to understand the origin, maintenance, and consequences of species diversity when evaluating community ecology.

An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. Freshwater ecosystems may be lentic (slow moving water, including pools, ponds, and lakes); lotic (faster moving water, for example streams and rivers); and wetlands (areas where the soil is saturated or inundated for at least part of the time).

In ecology, a disturbance is a change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. A disturbance can also occur over a long period of time and can impact the biodiversity within an ecosystem. Ecological disturbances include fires, flooding, storms, insect outbreaks, trampling, human presence, earthquakes, plant diseases, infestations, volcanic eruptions, impact events, etc.

Not only invasive species can have a profound effect on an ecosystem, native species can also cause disturbance by their behavior. Disturbance forces can have profound immediate effects on ecosystems and can, accordingly, greatly alter the natural community’s population size or species richness. Because of these and the impacts on populations, disturbance determines the future shifts in dominance, various species successively becoming dominant as their life history characteristics, and associated life-forms, are exhibited over time.

The hydrology of the Strait of Messina accommodates a variety of populations of marine organisms. The intense currents and characteristic chemistry of the waters of the Strait determine an extraordinary biocoenosis in the Mediterranean Sea with a high abundance and diversity of species; the Strait of Messina, therefore constitutes an area of fundamental importance for biodiversity. Intense and alternate currents, the low temperature and an abundance of transported nitrogen and phosphorus transported to the surface from deep waters supports both pelagic and coastal benthic populations in a cycle of organic substance.

All this, with associated phenomena, determines an ecological rearrangement that simulates Atlantic conditions for species with a prevailing Western distribution. In fact, numerous primarily Atlantic species, for example the laminariae (large tawny algae), though also present in some other zones of the Mediterranean, succeed in forming true structured submarine forests only in the Strait of Messina and are evidence of the optimal environmental conditions there.

A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. Biotope is almost synonymous with the term "habitat", which is more commonly used in English-speaking countries. However, in some countries these two terms are distinguished: the subject of a habitat is a population, the subject of a biotope is a biocoenosis or "biological community".

It is an English loanword derived from the German Biotop, which in turn came from the Greek bios (meaning 'life') and topos ('place'). (The related word geotope has made its way into the English language by the same route, from the German Geotop.)