Community

Different types of population in habitat are studied under community ecology. Same kind of species constitute population but when different populations (different kind of species) interacts together with beneficial and mutual adjustments sharing same environment and habitat, the association is called community.

Examples of community include grassland, a pond, or a forest where different animal organism (population) interacts with plants (another population) in a natural area and sharing environment. Thus, community includes only interacting biotic components of ecology i.e. living organisms.

If we consider abiotic component (environment) associated with the biotic community component (different organisms) then it will be called ecosystem. Ecosystem and community vary on the basis of environment factors.

While walking in a forest we not only see different types of plants/trees like pine tree, or maple tree but also get glimpse of deer or squirrel or spider sometimes indicating a collection of different kind of species constituting populations (different) in that natural area sharing uniform environment. These different population are adapted to the same environment and influence each other through their associations either positive or negative and thus, shaping/forming a biotic community.

The association and assembly of different populations shape the structure, diversity, niches and dominance properties of biotic community.

These interactions can be direct or indirect or can be negative or positive (competition, predation, mutualism and so on).

Community has different meanings; some say it’s an assemblage of organisms of same kind habituating same area such as birds in grasslands or lizards in deserts etc.

Some ecologists describe it as group of specialized organisms occupying same habitat like in the forest copy insect feeding birds form a community.

Some ecologists referred to a term “Guild”.

In a specific habitat the species group sharing same property of feeding or foraging are termed as “guild”. In all of the above described definitions the community is restricted to habitat sharing assembly of interest species.

A community can be autotrophic (self sustaining) or heterotrophic.

An autotrophic community gains solar energy through plant photosynthesis. It forms a major community.

Heterotrophic heterotrophic community depends on organic materials which are fixed energy from outside.

Different minor communities such as heterotrophic microcommunities (for example, fallen logs consists of different populations such as termite species constituting one population, bacteria and fungi or other small populations of different species together forming a small micro communities) assembled to form major communities (autotrophic community).

Different species of population have overlapping terrestrial ranges where they coexist in a particular limited area representing a community. A community is composed of both plants and animals as their interaction is must for the survival of community.

Just like population has certain group characteristics not applicable on single organisms similarly community also have characteristic different than their constituent populations.

Structure and characteristics of community

Under the similar environmental conditions similar type of species found in communities which tend to overlap each other and because of several variations and other variations animals may shuffle between communities.

Characteristics

a.     Stratification

b.     Ecotone- Principle of edges- denser population in ecotone than both communities.

c.      Ecological dominance

d.     Diurnal and seasonal variations

e.      Pattern Diversity

f.       Periodicity

g.     Turnover

h.     Interdependence

Ecotone also called as tensional zone.

In comparison to the adjacent communities, the ecotone population has higher density with more species and this rule is called as Principle of edges.