ECOLOGICAL PYRAMIDS

Ecological pyramids are diagrams by which it is possible to represent the trophic levels of a food chain. There are three types of pyramids: number, biomass and energy.

In number pyramids, each rectangle indicates the number of individuals present at each trophic level.

Ecological pyramids are graphical ways of representing the trophic levels of a food chain . The pyramids are formed by overlapping rectangles, with each trophic level represented by a rectangle, whose dimensions are equivalent to the values ​​presented by each level. The base of the pyramid represents the producer level; then consumers are represented . The level of decomposers is not represented in the ecological pyramids.

types of pyramids

→ Pyramid of numbers : represents the number of individuals present in the food chain . Each rectangle represents the number of individuals at each trophic level. The pyramid of numbers does not take into account the size of individuals or biomass, thus, it can be represented in an inverted way , that is, having its base smaller than the top. This occurs when the number of producers is smaller than the number of consumers .

→ Biomass Pyramid : represents the amount of biomass at each level measured at a given time. Most pyramids of this type narrow towards the top, as biomass transfer is inefficient between trophic levels. However, some pyramids may be inverted , as some producers reproduce as quickly as they are consumed, thus, at the time of measurement, a lower biomass of producers is observed in relation to consumers .

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→ Energy Pyramid : represents the amount of energy, or net production , at each trophic level. Thus, one can observe the amount of energy that is lost in each transfer in the chain. As the measurement is made per unit of area or volume and per unit of time , it can indicate the productivity of an ecosystem , so there is no inverted representation of this pyramid. However, some information is lost because the decomposers are not represented there .

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