Ecology elements

Ecology

Ecology is the study of ecosystems.There are different types of ecosystems.Natural ecosystem and artificial ecosystem.The largest ecological system which

includes all the organisms of the earth and its total environment is Biosphere.

Ecosystem – abiotic factors

Ecosystem- Any system which includes all diverse components of biological environment and its interaction with its physical environment , so that the trophic structure , biotic diversities , material cycle in between living and nonliving part along with the energy flow are clearly defined.

Abiotic components of the ecosystem comprised of 1) the amount of inorganic substances involved in

material cycles.2) Amount and distribution of inorganic chemicals

such as chlorophylls etc. and organic material such as proteins carbohydrates etc.

Biotic factors

Biotic system includes the trophic structure of any ecosystem .

2 types of organisms –autotrophic and heterotrophic.

Heterotrophic organisms are divided in two types- macro animals and micro consumers.

Heterotrophic consumers are further divided into 3 groups

1. Primary consumers2. Secondary consumers and3. Tertiary consumers.

Function of Ecosystem

The important function of ecosystem is the movement of materials and energy between living and non living components of eco system.

Food chain is an important concept in this regard.

Food chain is the transfer of food energy from the producer through a series of organisms with repeated eating and being eaten.

2 types of food chains – Grazing food chain and Detritus food chain.

Some features of Food chain

The further along the food chain one goes, the less food (and hence energy) remains available.

Most food chains have no more than four or five links.

A change in the size of one population in a food chain will affect other populations.

Food web

A food web extends the food chain concept from a simple linear pathway to a complex network of interactions.

Food chain never operates in isolated sequence but are interconnected with each other forming some sort of interlocking pattern which is referred as food web.

Complexity of food web depends on two factors –

1) length and diversity of food chain

Continued……..

2) alternatives at different points of consumer in the chain.

The food web is divided into two broad categories: the grazing web, which typically begins with green plants, algae, or photosynthesizing plankton,

the detritus web, which begins with organic debris. In a grazing web, materials typically pass from plants to

plant eaters (herbivores) to flesh eaters (carnivores). In a detritus web, materials pass from plant and animal

matter to bacteria and fungi (decomposers), then to detritus feeders (detritivores), and then to their predators (carnivores).

FOOD WEB

Many interconnections exist within food webs. For example, the fungi that decompose in a detritus web may sprout mushrooms that are consumed by squirrels, mice, and deer in a grazing web.

Robins are omnivores, that is, consumers of both plants and animals, and thus are in both detritus and grazing webs. Robins typically feed on earthworms, which are detritivores that feed upon decaying leaves.

Nutrient cycle in Eco system

Energy cycle are infinite but nutrient cycle is finite.

Two types of nutrient – macro nutrient (C, H, O) -atmospheric source

micro nutrient (Cu, Fe, Co) – edaphic cycle.Nitrogen is available in both atmosphere

and soil.A variety of bio geo chemical process

controls the availability of nutrient in the environment.

Hydrological cycle

Carbon cycle

Nitrogen Cycle

Nitrogen is reserved mainly in rock deposits , atmospheric air and the living organisms.

Plant could not use Nitrogen available in atmosphere, it needs the process of nitrogen fixation.

Through the process of decay and decomposition of ammonia is formed.

Ammonia – Nitrite – Nitrate – Nitrogen.

Oxygen Cycle

The oxygen cycle is the Bio geo chemical cycle that describes the movement of oxygen within and between its three main reservoirs: the Atmosphere (air), the Biosphere (living things), and the Lithosphere (Earth's crust).

The main driving factor of the oxygen cycle is Photosynthesis and Photolysis which are responsible for the oxygen availability in earth.

Oxygen Cycle