Allogenic Process, RelatIon Between Water Bodies and Climate

Allogenic processes of lentic environment

Allogenic processes of the fresh include those processes which are due to the geochemical forces acting without the system. These processes exclude the biotic-abiotic interactions within the system. The allogenic processes may interrupt or reverse the wetland vegetation sequences which are due to the autogenic processes. The allogenic processes such as the gradual climate change slow down cutting by the stream erosion of the ridge which is damming the wetland may have such effects that they will be very hard to defeat from the evidence in the sediments while the allogenic processes such as the landslides, volcanoes, glaciation, earth movement may change flow pattern sufficiently to bring about the drastic changes in the developmental sequences of the freshwater ecosystem.

Relation between large water bodies and climate of adjacent area

The large water bodies and the climate of the adjacent area are interrelated which is discussed under the property of the water that the specific heat capacity of the water is very high i.e 4200 joules per gram per kelvin. Due to the presence of the high specific heat capacity, it can contain heat for the maximum period of time and loses heat slowly. This high specific heat capacity of the water has the high role in the climate of the adjacent area. During the time of summer, the large water body not only absorbs a large amount of heat but also make the adjacent area warm. Relative humidity is also high in the adjacent land than others. Different climatic factors like the temperature, rainfall, humidity, the wind have the more influence in the adjacent area. It has also impact on the adjacent flora and fauna of the surrounding land masses. Mostly the flora i.e vegetation around the large water bodies are of the marshy types with fully developed leaves usually bryophytes similarly the fauna of Amphibians type.

Distribution of water in the world

The total volume of water on the earth is 1.4 billion cubic meter. Among them, ocean water contains 97% of the total water and the fresh water contains 3% of the total water available by volume.

Among the 3% of the fresh water:

Water stored in the ice and glacier= 77.2%

Ground water and soil moisture= 22.4%

Lakes, swamps, river stream=0.36%

The total water bodies in the world can be shown as:

The total area of the different water bodies are given as below:

Autogenic process and role of light and temperature in the composition and distribution of freshwater organism

The autogenic process is due to the community itself which is as a result of its reactions with the environment modifies its own environment thus causing its own replacement by the new communities. These are the process of the vegetation change which is due to the biotic processes within the system. Various interactions of the peat formation plant species with the water create the conditions for the sequences of change in the wetlands.

Followings constitute the autogenic processes:

1: Progressive shallowing of water by the peat formation.

2: Slowing and eventually prevention of the free water inflow by the growth of the emergent vegetation.

3: Invasion of open water by the floating mats of plants.

4: Acidification of water.

5: Uptake of nutrient ions by the plants and their sequestration in peat.

6: Build up peat and maintenance by it of a high water table in case of the raised bogs this result in the independence of the site from the land-derived water supply.

7: Cutting off of sites from an access of fresh nutrient supplies.

Light

Light is the major factor that determines the distribution of the species in the freshwater, especially in the lentic ecosystem. On the basis of the light penetration, lentic bodies can be divided into the littoral zone, limnetic zone, and the profundal zone. Species distribution and the composition in these different zones are different which is a direct function of light i.e. for the species composition on these different zones of freshwater bodies refer to the question biotic community.

Temperature

Temperature also regulates the species distribution in the fresh water bodies. Thermal stratification phenomenon caused by the temperature has a very significant influence on the inhabitant biotic communities by causing seasonal overturn of the nutrients. Fluctuation of the temperature regulates breeding periods aestivation, hibernation, thermally oriented migration etc.

Ponds

Ponds are the lentic water bodies having the depth less than 13 feet. About 1000 ponds are reported from Nepal. Ponds may be permanent or temporary.

Permanent pond

Generally, permanent ponds are self-originated ponds. These may be originated from the outlet of the large lake and may be by river course. Permanent ponds may be artificial. For example; beavers ponds which are formed by the amphibian and rodents of the bank of the stream.

Temporary ponds

The nature of the ponds does not exist throughout the year. Some of the temporary ponds are;

I: Festival ponds: in these ponds water freeze in winter. These ponds are generally found in the polar region.

Ii: Vernal ponds: the ponds become dry during summer are vernal ponds.

Impoundments (reservoir)

Impoundments are the man-made lakes. The earlier reservoir was reported in Egypt i.e about 500 years ago but the rapid utilization of the reservoir has started after the 19^th century. Multipurpose plan is started after 1930. In a Nepal, construction of the dam was started in 1900.

Importance of reservoir

1: It can be used for the irrigation purpose for cropland.

2: Hydropower generation can be done by the impoundments.

3: Urban water supply can be fulfilled by the impoundments.

4: It has great importance in recreational value.

Effects of reservoir

The following are the effects of reservoir:

1: Development of the infectious disease. For example; cholera, dysentery, water-borne diseases.

2: Blockage of the migratory route of the migratory birds.

3: Running water system changed into the lentic water system.

4: Change in the upstream and the downstream ecosystem.

5: Change in the local terrestrial ecosystem and the socio-economic of the local people.

6: Change in the nutrient pattern in the upstream and the downstream on the basis of discharge.

References:

Miller, Jr. G.T. Living in the Environment. Wadsworth Publication, 2003.

S.C., Santee. Environmental Science. India, New Center: New Center Book Agency (P) Ltd, 2004.