Write a short note on pyramid of numbers and pyramid of biomass.
Ecological pyramids are graphical representations of the relationship between organisms of different trophic levles that can be expressed in terms of number, biomass or energy.
In most ecosystems, the pyramid of number is upright, i.e., producers are more in number than the herbivores and herbivores are more in number than the carnivores. But, the pyramid of number may be inverted as in a forest ecosystem, where the number of insects (primary consumers) are greater than the number of trees (producers).
The pyramid of biomass is upright, generally, as the biomass of producers is more than biomass of herbivores and that of herbivores is more than biomass of carnivores. But, it is inverted in ecosystems like sea ecosystem, where the biomass of fishes (primary consumers) exceeds than phytoplankton (producers).
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.