Ecosystem was proposed by A.G.Tansley in 1935. refers to the sume total of physical & biological factors operating in an area. The environment & system denotes an interacting interdependent,integrated complex. “Ecosystem is the structural & functional unit of ecology where the living organisms interact with each other & the surrounding environment„ Ecosystem may be defined as the system resulting from the integration of all living & non-living factors of the environment thus any structure & functional unit of biosphere where the organism interact with the physical environment so that a flow of energy leads to clearly defined trophic structure,biotic diversity & material cycle [e.g exchange of materials b/w living & non-living components]within the system is k/a an ECOLOGICAL SYSTEM OR ECOSYSTEM.
TYPES Of ECOSYSTEM:- An ecosystem can be small as or oasis in a desert ,or as big as or ocean, spanning thousand of miles. These are two types of ecosystem — (i) Terrestrial ecosystems (ii) Aquatic ecosystem
COMPONENTS Of AN ECOSYSTEM:- An ecosystem compromise abiotic components in the form of environment &biotic components in the form of organisms.
-:COMPONENTS Of ECOSYSTEM:-
ABIOTIC FACTOR:- Refer to the non-living things of the ecosystem, which includes the physical environment,i.e water,wind,soil along with inorganic substance it also involves climatic factors such as Sunlight, temperature, humidity.
FOLLOWING Are abiotic components of the ecosystem — (1) WATER:- Life without water is not possible, water, when mixed with the nutrients in the soil, helps to make it available for plants the productivity of the plants is dependent on water availability. Also during photosynthesis water is required by the plants.
(2) LIGHT:- Light is another important abiotic factor of the ecosystem.without light plant can’t prepare their food. So ,light plays an important role in the process of photosynthesis.these plants are called PRODUCERS, the entire living word depends.
(3) TEMPERATURE:-It is an important ecological factor. It varies with season &changes from the equator towards,the poles & from plains to the mountain tops living organisms can survive in a limited range of temperature while some can survive in a wide range of temperature.
(4) HUMIDITY:- It refers to the amount of water vapour in the air. This depends on temperature & pressure humidity affects the rate of transpiration in plants. The distribution of plants is affected by the humidity along with temperature & precipitation in some organism –Reproduction dependent –humidity.
(5)SOIL:-Soil is the habitat of many different microorganisms.plants grow on soil.it derives nutrition from the soil through roots.soil comprises different minerals which are required by the plants like magnesium is the important constituent of chlorophyll.
(6) TOPOGRAPHIC FACTOR:- it refers to the altitude & shape of the land which can also affect the distribution of organisms.
-: BIOTIC COMPONENTS:- The biotic component includes three groups –producers, consumers,decomposers.
(1) PRODUCERS:- These are green plants of the ecosystem.with the help of chlorophyll,green plants entrap the light energy of the sun & bind it by synthesising carbohydrates from simple inorganic compounds like Carbon Dioxide and water.this process is called PHAGOTROPHS.
CONSUMERS are following three types:- (a) PRIMARY CONSUMERS [HERBIVORES]:- These animal are the 1⁰consumers of the ecosystem [ecosystem,deer,goat,cattle, grasshopper etc] are the herbivores of terrestrial ecosystem & crustaceans,molluscs, protozoans & many fishes are the herbivores of equatic ecosystem.
(b) SECONDARY CONSUMERS:- These are primary carnivorous which eat herbivores,frog,fox,centipedes,fishes,predatory birds,lion,&tiger are the eg.of secondary consumers.
(c) TERTIARY CONSUMERS:- These are 2⁰carnivores ,which eat the 2⁰consumers .e.g-snake eats insectivorous frog.
DECOMPOSERS OR REDUCERS:-Bacteria fungi & moulds are the decomposers or REDUCERS of the ecosystem. They obtain their food by breaking the complex organic compounds from dead plants & animals into simple compounds.these are released in the atmosphere & are utilised by producers for the synthesis of organic food. The decomposers are called Micro consumers or saprotrophs.