Major Ecosystem Types-II

Pond Ecosystem

It is a small fresh water aquatic system where water is stagnant. Ponds may be seasonal in nature. Ponds are usually shallow water bodies which play very important role in villages where most of the activity center around pond. They contain several types of fungi, aquatic plants, insects fish, and birds.

Lake Ecosystem

Lakes are usually fresh water bodies with standing water. They have shallow water zone called Littoral Zone. An open water zone where effective penetration of solar light takes place called Limnetic Zone and deep water area where light is neglible is known as Profundal/dark Zone.

ORGANISMS- The lake ecosystem have several type of organisms.

i. Planktons: Floats on the surface of water like phytoplanktons and zooplanktons.

ii. Nektons: That swims like fishes.

iii. Neastons: That rest or swim on the surface like beetles.

iv. Benthos: That are attached to bottom segments like snails.

v. Periphytons: That are attached to other plants or any other surface like  crustaceans [crabs].

Stratification

The lake show stratification or zonation based on temperature difference. During summer top water become warmer than bottom water. Therefor only the top water layer circulates without mixing with other layer. Thus forming distinct zonation.

Epi-limnion - warm lighter circulating surface layer.

Hypo-limnion - cold viscous non-circular bottom water.

[NOTE- In between the two layer is thermo-cliene the region of sharp drop in temperature]

STREAMS

These are freshwater aquatic ecosystem where water current is the major controlling factor. 

Oxygen and nutrient in the water is not more uniform and land water exchange is more extensive although stream organisms have to face more extremities of temperature and action of current as compared to pond or lake organism. 

But they do not have to face oxygen deficiency under natural conditions. This is because the streams are shallow have a large surface exposure to air and constant motion with churns water and provide abundant.

Their dissolved oxygen level is higher than that of ponds.

Even though the green plants are much less in number. 

Stream animal have a narrow range of tolerance of oxygen that is the reason why they are suspendable to any organic pollution.

Thus streams are the worst victim of industrial development. 

Rivers are large stream that flow downward from mountain highland and flowing through the lakes and falling into the sea.

 So, the river stream show a series of different condition:

(i) The Mountain highland:- Part has cold clearwater rushing down as water flows with large amount of dissolved oxygen the plant are attached to rocks and fishes are cold blooded, high oxygen requiring fishes like trout.

 (ii) In the second phase on the gentle slope water are normal and support luxarial growth of plants and less oxygen requiring fish.

(iii) In the third phase river water are very rich in biotic diversity , moving down the hill river shape the land they bring with land lot of slit rich in nutrients which is deposited in the planes and in the delta before reaching the ocean.

Oceans

 These are large reservoirs  of water covering more than 70% of Earth's surface and play a key role in survival of 2,50,000 marine species serving as food for organism give a huge variety of sea products and drugs.

 Ocean provide us iron, Phosphorus, magnesium, oil, natural gas, sand and gravel.

 Oceans are the major sink of carbon dioxide and play an important role in regulating many biogeochemical cycles and hydrological cycles therefore regulating Earth's climate.

 Oceans have two major life zones, the first one is costal zone and the second is Open Sea.

I. Coastal zone with relatively warm, nutrient-rich, and have  shallow water due to high nutrient an apple ample sunlight (i.e. high primary productivity) coastal wetland harbour rich biodiversity. 

II Open Sea - Deeper part of the ocean always form the continental shell, it is vertically divided into three regions that are :

1. Euphotic zone - This receives abundant sunlight and show high photosynthetic activity

 2. Bethyal Zone - This receives dim light and usually geological active

3. Abyssal Zone (dark zone) - Here, no primary source of energy that is no solar radiation reaches here.

ESTUARY

An estuary is partially enclosed coastal area at the mouth of river where fresh and salty sea water meet. 

These are the transition zone which are strongly affective by tidal action.

The organism present in estuaries show a wide range of tolerance to temperature and salinity such organism are known as Eurythermal (temperature variations) - Euaryhalime (survival in salinity). 

Coastal base and tidal marshes are example of estuaries.
Estuaries have rich biodiversity and many species are endemic. There are many migratory species of fish like Salmons, eels in which half of the life spent  in fresh and half in salty water.

Esturies are much used to human beings due to their high food potential.However the ecosystem need to be managed judiciously and protected from pollution.

Biodiversity and its conservation

 1. Genetic biodiversity
 2. Species biodiversity 
 3. ecosystem 

-> food web: the more Complex the more better because of biodiversity.


There are 18 Biosphere Reserves are present in India ( in 2001). Some of the main are-

Himachal Pradesh - Cold desert 

Uttarakhand - Nanda Devi

Sikkim- Kanchenjunga

Asam - Mana 

Arunachal - Dhibru 

West Bengal - Sundarban 

Biogeographical classification of India :

1. Trans Himalayan 

2. Himalayan 

3. Desert

4. semi-arid 

5. Western Ghats 

6. Deccan Peninsula 

7. Gangetic planes

8. North-India

9. Island

10. Coast