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प्रश्न
What are the three types of ecological pyramids? What information is conveyed by each pyramid with regard to structure, function and energy in the ecosystem?
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उत्तर
The three ecological pyramids that are usually studied are
- pyramid of number
- pyramid of biomass and
- pyramid of energy.
- Any calculations of energy content, biomass, or numbers has to include all organisms at that trophic level. No generalisations we make will be true if we take only a few individuals at any trophic level into account. Also a given organism may occupy more than one trophic level simultaneously. One must remember that the trophic level represents a functional level, not a species as such. A given species may occupy more than one trophic level in the same ecosystem at the same time; for example, a sparrow is a primary consumer when it eats seeds, fruits, peas, and a secondary consumer when it eats insects and worms.
- In most ecosystems, all the pyramids, of number, of energy and biomass are upright, i.e., producers are more in number and biomass than the herbivores, and herbivores are more in number and biomass than the carnivores. Also, energy at a lower trophic level is always more than at a higher level.
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संबंधित प्रश्न
In an ecosystem dominated by trees, the pyramid (of numbers) is ______ type.
In a food chain, the herbivores are represented by
(A) producers
(B) primary consumers
(C) secondary consumers
(D) decomposers
Which organisms constitute the last trophic level?
“The pyramid of biomass is not always upright.” Explain the statement.
Answer the following question.
What is an ecological pyramid? Compare the pyramids of energy, biomass, and numbers.
Write any two limitations of ecological pyramids.
'The pyramid of energy is always upright.' Explain
Give an example of an ecosystem that shows an inverted pyramid of biomass.
Distinguish between the upright and inverted pyramid of biomass.
Define ecological pyramids.
Pyramid of energy in grassland and pond ecosystem is always ______.
Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are correct?
Organisms at a higher trophic level have less energy available. Comment.
Write a short note on pyramid of numbers and pyramid of biomass.
(a) Draw a pyramid of numbers where a large number of insects are feeding on the leaves of a tree. What is the shape of this pyramid?
(b) Will the pyramid of energy be also of the same shape in this situation? Give a reason for your response.
The biomass of a standing crop of phytoplankton is 4 kg/m2, which supports a large standing crop of zooplankton having a biomass of 11 kg/m2. This is consumed by small fishes having a biomass of 25 kg/m2, which are then consumed by large fishes with a biomass of 37 kg/m2.
Draw an ecological pyramid indicating the biomass at each stage and also name the trophic levels. Mention whether it is an upright or inverted pyramid.
| In a forest ecosystem, a large population of insect feeds upon a banyan tree. Several small birds feed upon these insects. The small birds are fed upon by big-sized birds. |
- With respect to this ecosystem, draw a pyramid for each biomass and a pyramid of number.
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If 20,000 Kcal energy is available at the level of insects, calculate the amount of energy available at the level of big-sized birds.
