Q.8 Define ecology and ecosystems. Enumerate different types of ecosystems and explain any two of them in detail. (AKTU. - 2007-08)
Related Questions -
Q. What is an ecosystem? Classify ecosystem on the basis of energy sources. (AKTU. - 2008-09)
Q. Define the concept of ecosystem. (AKTU. 2009-10)
Q. Define ecology and ecosystem. Explain role of producers, consumers and decomposers in a ecosystem. (AKTU. - 2012 - 13)
Q. What is an ecosystem? Name and explain various types of ecosystems. (AKTU. - 2012 - 13)
Ans. Ecology: - (AKTU. - 2010 - 11)
Ecology is defined as the different categories of the trophic structure and also trophic function.
Ecosystem: - (AKTU. - 2008 - 09, 10 - 11, 11 - 12)
The term ‘Ecosystem’ was first proposed by A.G. Tansley in 1935. Accordingly to him it is defined as “the system resulting from the integration of all the living and non-living factors of the environment”.
Ecosystem is also defined as : - a natural functional ecological unit comprising of living
Ecosystem is also defined as : - a natural functional ecological unit comprising of living organism (biotic community) and their non living (abiotic or physio chemical) environment that interact to form a stable self-supporting system. A pond, lake, desert, grassland, meadow, seas, streams, cities etc. are all examples of ecosystems.
Types of Ecosystem: -
(i) Natural Ecosystems (Biomes): -
Natural ecosystems operate by themselves under natural conditions without any interference by man. Natural ecosystems carry out many public service functions for us. On the basis of particular type of habitat, they are further sub-divided as:
(a) Terrestrial Biomes (Ecosystems): -
They are often defined by the vegetation types that dominate the community.
(b) Aquatic Biomes (Ecosystems): -
They fall into two categories, viz., freshwater and marine.
(ii) Artificial Ecosystems (Biomes): -
They are maintained artificially by man. A pond constructed as part of a waste water treatment plant is an example of artificial ecosystem. In artificial ecosystems, the management can vary over a wide range of actions.
Types of Ecosystems Based on Energy Resources: -
Ecosystems rely on two major sources of energy, the sun and chemical or nuclear fuels. So, on the basis of the major input, there can be solar-powered and fuel-powered ecosystems. On the basis of energy resources, the ecosystems are classified as:
(i) Unsubsidized Natural Solar-Powered Ecosystems: -
In these types of ecosystems, the only source of power/energy is solar energy. For example, ocean, upland forests, grasslands, etc.
(ii) Naturally Subsidized Solar-Powered Ecosystems: -
In these types of ecosystems, the main source of energy is sun, which is augmented by natural non-solar energy.
(iii) Man Subsidized Solar-Powered Ecosystems: -
In these types of ecosystems, auxiliary fuel or other energy, like man and machine labour, is supplied by man. Here again, the main source of energy is sun. Examples of these types of ecosystems are agriculture and aquaculture.
(iv) Fuel-Powered Ecosystems (or Urban-Industrial Ecosystems): -
In these ecosystems, the sun energy is replaced by highly concentrated potential energy of fuel, chemical or nuclear fuel. Examples of these systems are cities, suburbs, industrial parks, etc. These systems are man’s wealth generating and also pollution generating systems. In these systems there is no limit of energy input. The energy input varies from 1,00,000 to 30,00,000 kcal/m2/year and the average being 20 lacs kcal/m2/year. These systems are parasitic in nature, because they depend on other ecosystems, as here consumption is large and production is bootless. For example, Mughal Gardens, Apughar, etc.
Detail Study Of Two Ecosystem: -
1. Forest Ecosystem: -
A forest ecosystem is a complex of living and nonliving elements which interrelate.
Types and Characteristic features: -
(i) Tropical Savannah: -
Tropical savannahs or tropical seasonal forests occur where rainfall is high (100 to 150 cm) but very seasonal (wet seasons alternate with dry season). They are warm climate plains characterized by coarse grass ans scattered trees on the margins of tropics. They are located primarily in South and Central America, Africa, Australia, South-east Asia and India.
Temperate Forests: -
Temperate forests are in regions where the climate changes a lot from summer to winter. The annual precipitation ranges between 75 cm and 150 cm. Temperate forests are almost always made of two types of trees, deciduous and evergreen. Deciduous trees are trees that lose their leaves in the winter. Evergreens are trees that keep them all year long, like pine trees.
Taiga or Boreal Forest: -
The taiga biome includes the northern coniferous forests of the cold climates of high latitudes and high altitudes that extends as an east-west band across North America, Europe and Asia, just below the 600N latitude.
Tiaga ecosystems are characterized by dense strands of relatively small trees, typically under 30 m, which are so dense that little light reaches the floor of the forest. Characteristic features of this ecosystem (biome) is the presence of numerous lakes.
Temperate Shrub Forest: -
This biome, also known as mediterranina shrub forest, occurs under drier climates with low winter rainfall followed by drought in the rest of the year. The most distinctive feature of this biome is the Chaparral, a miniature woodland dominated by dense stands of shrub that rarely exceed a few meters in height. Chaparrals are found along the Mediterranean, coast of California, Chile, South Africa and South Australia.
