Koustav Pal

Ecology

Ecology is a wide term used to describe the study of the interactions of the various organisms within a particular environment.

We need ecology to understand on how the environment works, and how our anthropological actions will effect the environment and its residing organisms.

What is “Ecology”?

Habitat:A place in an environment where an organism lives.

If an organism lives in a very small, localized area of that habitat, then it is known as a microhabitat.

Definitions

For example, Vaibhav’s habitat is his house at Highland Woods. His specific microhabitat may be his Civic, as he practically spends most of his time in it.

Population: A group of organisms of the same species present

within a particular habitat at any one time. These organisms live and breed together.

Community:The populations of all different species living in a particular habitat at any one time forms a group known as a community.

For example, the students may be thought of an individual population in CIS, but the community includes the teachers, the dadas, and even the life on the school grounds, such as the grass and trees.

Cont.

The niche of an organism is its particular role played in its respective ecosystem. It is unique for each different species, and each different component of that species will also have a unique species.

For example, the niche of a butterfly is to feed on flowers, hence inducing cross-pollination. However, its eggs and the pupae may have a niche to act as food for other organisms.

Niche

Niches also influence the distribution of where a particular species will live in an ecosystem.

Some species may both photosynthesize using light, but due to temperature differences, they may spread out so that one is in the cooler area, and another will occupy warmer areas as this is optimal to their metabolism. As a result, they naturally distribute, avoiding competition and changing the distribution.

Distribution due to a Niche

Succession: With time, an existing ecosystem will gradually change until it reaches the most stable ecosystem. Simultaneously, the plant and animal communities will change till they reach the most stabile climax community.

A good example of succession are the islands of Hawaii. Initially just freshly ejected lava from its various volcanoes, each island developed from scratch into its stable climax community through primary succession.

Evolution of Ecosystems

The stages in primary succession are mainly caused by changes in the abiotic factors, which as a result cause changes in the animal and plant communities.

Each stage is known as a seral stage, where the process of the formation of the climax community is known as a sere.

Primary Succession

1. Formation of Soil:As the barren area is usually rock, soil must be formed by some form of erosion, or must be brought by an external source.

Formation of Humus, or the topmost layer of soil must occur. This is composed of detritus, and as it decays, it further contributes free mineral ions for growth of the pioneer species.

The primary pioneer species are known as Xerophytes, as they usually have the tendency to survive in dry conditions.

Seral Stages in Primary Succession

2. Once the primary humus forms, other species can colonize the humus. As a result, more species join the community, and die, further contributing their remains to the ever-growing humus layer, and as a result, the community increases in size.

This continues, and with the increasing plant biodiversity, the animal community similarly becomes more adept, until it reaches the optimal size of plant and animal community, and this is known as the climax community.

Cont.

A theory proposed by FE Clements, a climax community is the most stable form of a community which has reached its last and final stage of succession. It is dependent upon the abiotic factors, such as climate.

Changing the climate hence will cause succession to occur again .

Climax Community

Secondary Succession occurs mainly due to a large change in the climax community. But as soil is already formed, succession and the sere process occurs faster.

For example, in the case of a wildfire which wipes out a particular zone, the scorched area will be favored by mosses suitable for the particular burnt areas, and nearby soil will be available for colonization by pioneer species, and animals will follow quickly.

Secondary Succession

1. Quadrats:Quadrats are used by taking an x y z

coordinate map, and using a computer to generate random coodinates. The quadrat is hence placed gently at this location, and the different species at each quadrat space are hence recorded.

Measuring the Biodiversity of a Habitat

2. TransectsTransects are another further

method of using quadrats to hence determining the directional variation of species seen in a ecosystem.

A gridline of the area to be observed is drawn, and the biotic and abiotic factors are observed with quadrats and essential sensors, where the data is recorded perpendicular to the unidirectional physical forces causing the variation.

Cont.

3. Mark, Release, Recapture.

Animals are marked, (often with sensors), released back into the wild, and after some time, they are again recaptured. This helps to determine the population of animals.

Works Cited"About Ecology." British Ecological Society. British

Ecological Society, n.d. Web. 31 Aug. 2014. <http://www.britishecologicalsociety.org/about-ecology/>.

Clegg, C. J. Hodder Edexcel A2 Biology. London: Hodder Education, 2009. Print.

"Ecology." Cornell. Cornell, n.d. Web. 31 Aug. 2014. <http://blogs.cornell.edu/bioee1610/2011/09/06/the-importance-of-ecology-in-today%E2%80%99s-society/>.

"Niche Estimate." Science as Verb. N.p., n.d. Web. 31 Aug. 2014. <http://scienceasaverb.files.wordpress.com/2010/10/complex-niche-estimate.png>.

Bibliography