Given below is a list of autotrophs and heterotrophs. With your knowledge about food chain, establish various linkages between the organisms on the principle of 'eating and being eaten'. What is this inter-linkage established known as?
Algae, hydrilla, grasshopper, rat, squirrel, crow, maize plant, deer, rabbit, lizard, wolf, snake, peacock, phytoplankton, crustaceans, whale, tiger, lion, sparrow, duck, crane, cockroach, spider, toad, fish, leopard, elephant, goat, Nymphaea, Spirogyra.
Food Chain and Food Web A straight line sequence of 'who eats whom' or eating and being eaten in an ecosystem is called a food chain. A network of cross connecting food chains involving producers, consumers and decomposers are termed as a food web.
Lion, Tiger - Top carnivore (Top tropic level)
Spider, cockroach, lizard, wolf, snake, toad, fish, crane - Secondry Consumer (IIIrd trophic level).
Crustaceans, grasshopper, deer, mouse, squirrel, rabbit, elephant, goat - Primary Consumer (IInd trophic level).
Phytoplankton, algae, Hydrilla, maize plant, Nymphaea, Spirogyra - Producers (Ist trophic level).
"The energy flow in the ecosystem follows the second law of thermodynamics." Explain.
According to second law of thermodynamics every activity involving energy transformation (According to first law - energy can be transferred and transformed) is accompanied by dissipation of energy as heat and only a part of it is used in building up tissues in an organisms.
This trapped energy as biomass is transferred to next trophic level. According to Lindman law only $10 \%$ of the stored energy is passed from one trophic level to successive trophic level.
What will happen to an ecosystem if
(a) All producers are removed
(b) All organisms of herbivore level are eliminated and
(c) All top carnivore population is removed
(a) Removal of all producer reduce primary production in the ecosystem. Hence, no biomass will be available to the successive/higher trophic level or heterotrophic organisms.
(b) Elimination of all organisms of herbivore level results into an increase in primary productivity and biomass of producer and carnivorous animal will not survive due to inavailability of food herbivores.
(c) Removal of top carnivores also disturb the ecosystem as it will result in huge increase in number of herbivores which will finish plants (producers) creating desertification.
Give two examples of artificial or man made ecosystems. List the salient features by which they differ from natural ecosystems.
Aquarium and farm house, are artificial or man made ecosystem. In artificial ecosystem biotic and abiotic component are maintained artificially like cleaning, feeding and supply of oxygen to fishes in aquarium and irrigation in crop or farm house.
While abiotic and biotic component of natural ecosystem are maintained naturally like nutrient cycle, self sutainability, prevention of soil erosion, pollutant absorption and reduction of threat to global warming (ecological servicer), etc.
The biodiversity increases when one moves from the pioneer to the climax stage. What could be the explanation?
During ecological succession biodiversity increase or changes from pioneer to climax stages.
Following are the effects of ecological succession
(a) It leads to changes in vegetation that affects food and shelter for various types of animals.
(b) As succession proceeds, the numbers and types of plants, animals and decomposers also change.
(c) At any time during primary or secondary succession, natural or human induced disturbances (fire, deforestation, etc.) can convert a particular seral stage of succession to an earlier stage.
Also such disturbances can create new conditions that encourage some species and discourage or eliminate other species of producer, consumers and decomposers.
(d) Over the time, they are succeeded by bigger plants and, ultimately a stable climax forest community is attained.
(e) The climax community remains stable if the environment remains unchanged.
(f) With time, the xerophytic habitat may gets converted into a mesophytic one.