Question

ANSWER PLEASE ........​

Answer 1

Answer:

Some of the major biogeochemical cycles are as follows: (1) Water Cycle or Hydrologic Cycle (2) Carbon-Cycle (3) Nitrogen Cycle (4) Oxygen Cycle.

The producers of an ecosystem take up several basic inorganic nutrients from their non-living environment. These materials get transformed into the bio mass of the producers. Then they are utilized by the consumer population and are ultimately returned to the environment with the help of the reducers or decomposers

This cyclic exchange of nutrient material between the living or­ganisms and their non-living environment is called biogeochemical cycle. As indicated by the name the nutrients circulate through life {bio) and through earth (geo) repeatedly (cycle). The biogeochemical (material or nutrient) cycles conserve the limited source of raw materials in the environment.

Common Biogeochemical Cycles are:

(1) Water Cycle or Hydrologic Cycle:

In this cycle;

(a) Water from the transpiring plants, oceans, rivers and lakes evaporates into the atmosphere

ADVERTISEMENTS:

 

(b) These water vapours subsequently cool and condense to form clouds and water.

(c) Water returns to the earth as rain and snow.

Water Cycle

(2) Carbon-Cycle:

Most of the carbon dioxide enters the living world through photosynthesis. The organic compounds synthesized are passed from the producers (green plants) to the consumers (herbivores and carnivores). During respiration, plants and animals release carbon back to the surrounding medium as carbon-dioxide. The dead bodies of plants and animals as well as the body wastes, which accumulate carbon compounds, are decomposed by micro-organisms to release carbon dioxide.

Carbon is also recycled during burning of fossil fuels.

Carbon Cycle

(3) Nitrogen Cycle:

Nitrogen of the atmosphere is in the elemental form and cannot be used as such by living organisms. It has to be “fixed” i.e. combined with other elements such as hydrogen, carbon or oxygen to become usable for the green plants.

Nitrogen is continuously entering into the air by the action of denitrifying bacteria and returning to the cycle through the action of lightening and electrification.

(4) Oxygen Cycle:

Oxygen required for respiration in plants and animals enters the body directly from the surrounding medium (air or water).

Oxygen returns to the surroundings in the form of Carbon-dioxide or water. It also enters the plant body as carbon dioxide and water during photosynthesis and is released in the form of molecular oxygen as a by-product in the same proc­ess for use in respiration. Thus, the cycle is completed.

Nitrogen Cycle

Ecosystem is a functional system which in a balanced condition, is self-sufficient and self-regulating. A balanced ecosystem is essential for the survival of all living organisms. Organisms at each trophic level in a food chain are preyed upon by an organism at the next higher trophic level, for example, herbivores feed on the plants and are in turn eaten by the predators.

If the numbers of herbivores increase in a specific area, there will be a rapid destruction of the vegetation, which in turn will eventually destroy the herbivores (due to lack of food). So, the population of herbivores is kept in check by predators such as lions and tigers.

Oxygen Cycle

Through these interactions in the food web, the population of each species, is held in check by the carrying capacity of the environment i.e. the environment’s ability to provide space and food to the organisms, and the ecosystem maintains its balance (ecological balance or balance of nature).

The tendency of the biological systems to resist change and to remain in a state of dynamic equilibrium is known as homeostasis (homeo = same; stasis = standing).

Generally, the ecosystems are named after the type of organism and habitat conditions, e.g.:

(a) Forest ecosystem

(b) Grassland ecosystem

(c) Desert ecosystem

(d) Aquatic ecosystem

(e) Crop ecosystem

(f) Urban ecosystem

However, several ecosystems can be inter-related and sometimes several small ecosystems (micro ecosystems) form a large ecosystem (macro ecosystem) for instance,

Bird ecosystem → Tree ecosystem → Forest ecosystem → Terrestrial ecosystem → World ecosystem.