User:VetMedIsLife7/Community (ecology)

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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 between coexisting populations. The primary focus of community ecology is on the interactions between populations as determined by specific genotypic and phenotypic characteristics. **When studying community ecology, it is important to understand the origin, maintenance, and consequences of species diversity within a community. **

On a deeper level the meaning and value of the community concept in ecology is up for debate. Communities have traditionally been understood on a fine scale in terms of local processes constructing (or destructing) an assemblage of species, such as the way climate change is likely to affect the make-up of grass communities. Recently this local community focus has been criticized. Robert Ricklefs, a professor of Biology at the University of Missouri and author of Disintegration of the Ecological Community, has argued that it is more useful to think of communities on a regional scale, drawing on evolutionary taxonomy and biogeography, where some species or clades evolve and others go extinct. ''**In the past, community ecology focused mostly on patterns of organisms and species. Today, more focus is placed on conducting experiments and establishing mathematical models.**''

Influential species[edit]
Certain species have a greater influence on the community through their direct and indirect interactions with other species. **Influential species are significant in identifying and categorizing communities., however, their population can be affected by abiotic and biotic disturbances* The loss of these species results in large changes to the community, often reducing the stability of the community. **''Climate change, the introduction of invasive species, and contamination (radioactive contamination, oil spills) can affect the functioning of key species and thus have knock-on effects on the community processes. With industrialization and the production of human-made products, chemical contaminants have dramatically altered communities and entire ecosystems. 2**''

Theories of community structure[edit]
Community structure is the composition of the community and is measured through biological networks that display interactions between two or more species. An example of a biological network that establishes community structure is a food web. **It is often measured through biological networks, such as food webs, that display interactions between species.**

Predation[edit]
Main article: Predation

Predation is hunting another species for food. This is a positive-negative interaction, the predator species benefits while the prey species is harmed. Some predators kill their prey before eating them, also known as kill and consume. For example, a hawk catching and killing a mouse. Other predators are parasites that feed on prey while alive, for example, a vampire bat feeding on a cow. Parasitism can however lead to death of the host organism over time. Another example is the feeding on plants of herbivores, for example, a cow grazing. Predation may affect the population size of predators and prey and the number of species coexisting in a community.**herbivory is a kind of predation in which the prey is a plant. Upon detecting herbivory, the plant may pump toxins into the leaf to dissuade the herbivore. In response, the herbivore may quickly chew out a pattern to isolate part of the leaf from the toxins and then dine in relative salubrity **

Mutualism[edit]
Main article: Mutualism (biology)

Mutualism is an interaction between species in which both **species** benefit.

Neutralism[edit]
Main article: Neutralism (biological interaction)

** Neutralism is where species interact, but the interaction has no noticeable effects on either species involved. Interactions that occur are either indirect or incidental. Due to the interconnectedness of communities, true neutralism is rare. Examples of neutralism in ecological systems are hard to prove, due to the indirect effects that species can have on each other. However, one example is tarantulas living in a barren region and cacti living in a barren region.**

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=== R eferences ===

3) Journal of Advanced Research in Dynamical and Control Systems Vol. 6, Issue. 3, 2014, pp. 62-78 Online ISSN: 1943-023X Stochastic effects on an ecosystem with predation, commensalism, mutualism and neutralism