Community

A. Definition of Community

Community is a collection of various populations who live at a time and specific regions that interact and influence each other. Community has a degree of integration is more complex when compared with individuals and populations.

B. Community Name

Name of the community should be able to provide information on the nature of the community. The most simple way, naming it by using words which may indicate how the form communities like grasslands, deserts, forests of teak.

The best way to call the community is to take some clear and steady nature, whether living or not. This summary is based on the naming of the community can:

1. Establish or major structures like the kind of dominant form of life or other indicators such as the pine forest, forest agathis, teak forests, or forests Dipterocarphaceae, can also be based on the nature of the dominant vegetation such as forests sclerophyll

2. Based on the physical habitat of the community, such as community mudflats, sand beach community, the community of the oceans, etc.

3. Based on the properties or signs of functional eg metabolic type community. Based on the properties of the natural environment such as climate, for example, found in tropical regions with rainfall evenly distributed throughout the year, it is called a tropical rain forest.

C. Various Communities

In nature there are various communities that can be broadly divided into two parts:

1.Aquatic Communities

The Communityfor example contained in the sea, lake, river, ditch or pond

2. Communityterrestrial

Namelygroups of organisms found in the yard, in a forest, grassland, desert, etc.

D. Community Structure

Character kominitas

1. Qualitative, such as composition, life form, phenology and vitality.

Vitality describes the growth and proliferation capacity of the organism.

2. Quantitative, such as frequency, density and relative density.

Frequency of attendance is the value that states the amount of presence of a species in a habitat.

Density (density) expressed as a number or biomass per unit sample, or per unit area / volume, or unity arrest

3. Synthesis is a process of change in the community that goes toward a direction that takes place regularly definite directional slow and predictable. Succession succession occurs as a result of the modification of the physical environment in the community and takes time. The process ends with a community or ecosystem called klimas. In this level the community has experienced homoestosis. According to the leading edge concept of succession is the turn of the kinds of pioneer by species more solid that is in accordance with the environment.

Succession can be divided into two types:

¬ primary successionie when disturbed ecosystems are heavy, so the initial community (there) be lost or totally destroyed, causing the place is not nothing left, and finally there was a new habitat.

¬ the secondary succession process is similar to those seen in the primary succession, the difference is on the state of the ecosystem damage or initial conditions in their habitat. The Ecology impaired, but not total, there are still remaining communities.

E. Interactions

In the community, all organisms are part of the community and among its components are interconnected through a diversity of interaction. Interactions between components ecology can be an interaction between organisms, antarpopulasi, and communities.

1. Interaction between organisms

All living things always depend on other living creatures. Each individual will always be associated with other similar individuals or other types, both individuals in a population or individuals from other populations. Such interactions more we see around us.

The interaction between organisms in a community there is very close and there are less closely. Interactions between organisms can be categorized as follows.

¬ Neutral is not mutually interfere relationships between organisms in the same habitat that is not beneficial and not detrimental to both parties, so-called neutral. For example: between a dragonfly and a cow.

¬ Predation is the relationship between prey and predator (predator). This relationship is very close because without prey, predators can not live. In contrast, predators also serves as a controller of prey populations. Example: Lion with prey, the antelope, deer, and owls with rats.

¬ Parasitism is a relationship between organisms of different species, bilasalah a living organism to other organisms and taking food from the host / host so detrimental to the host. Example: Plasmodium to humans, Taeniasaginata with cows, and a parasite with the host tree.

¬ komensalisme are the relations between two organisms of different species in the form of life together to share food resources; one species benefit and other species are not harmed. Examples orchids with the host tree.

¬ Mutualism is a relationship between two organisms of different species that are mutually beneficial to both parties. For example, Rhizobium bacteria living in root nodules of beans.

2. InteractionAntarpopulasi

Betweenone population with other populations is always an interaction directly or indirectly in komunitasnya.Contoh antarpopulasi interaction is as follows.

Alelopati an interaction antarpopulasi, when the population of the produce substances that can inhibit the growth of other populations. For example, around the walnut tree (Juglans) rarely overgrown with other plants because these plants produce substances that are toxic. In terms alelopati microorganisms known as anabiosa.Contoh, fungus Penicillium sp. can produce antibiotics that can inhibit the growth of certain bacteria.

Competition is an interaction antarpopulasi, when there antarpopulasi the same interests so that there is competition to get what is needed. For example, competition between the goat population with a population of cows in the pasture.

3. Inter-Community Interaction

Community is a collection of different populations in a same area and interact. Examples of communities, such as rice fields and river communities. Community paddy prepared by a variety of organisms, such as grain, grasshoppers, birds, snakes, and weeds. River communities consisting of fish, algae, zooplankton, phytoplankton, and decomposers. Between the river and paddy community interaction in the form of the circulation of nutrients from river water to the fields and the distribution of living organisms from both communities.

The interaction between communities is quite complex because it involves not only the organism, but also the flow of energy and food. The interaction between communities can be observed, for example on the carbon cycle. Carbon cycle involves different ecosystems eg, sea and land.

4. Interaction between Components Biotic with Abiotic

Interactions between biotic component of ecosystems with abiotic form. Relations between organisms and their environment led to the flow of energy in the system. In addition to energy flow in ecosystems there are also structural or trophic level, biotic diversity, and material cycles.

With the existence of these interactions, an ecosystem can maintain balance. Arrangements to guarantee this balance is the hallmark of an ecosystem. If this balance is not obtained then will encourage the changing dynamics of the ecosystem to achieve a new balance.