Here is your essay on Most Important Types of Ecological Pyramids !
The ecological pyramids may be of following three kinds:
1. Pyramids of number:
It depicts the number of individual organisms at different trophic levels of food chain. This pyramid was advanced by Charles Elton (1927), who pointed out the great difference in the numbers of the organisms involved in each step of the food chain. The animals at the lower end (base of pyramid) of the chain are the most abundant.
ADVERTISEMENTS:
Successive links of carnivores decrease rapidly in number until there are very few carnivores at the top. The pyramid of number ignores the biomass of organisms and it also does not indicate the energy transferred or the use of energy by the groups involved. The lake ecosystem provides a typical example for pyramid of number (Fig. 18.5 and 18.6).
2. Pyramid of biomass:
The biomass of the members of this food chain present at any one time forms the pyramid of the biomass. Pyramid of biomass indicates decrease of biomass in each tropical level from base to apex.
ADVERTISEMENTS:
For Sample, the total biomass of the producers ingested by herbivore more than the total biomass of the herbivores in an ecosystem likewise, the total biomass of the primary carnivores (or secondary consumer) will be less than the herbivores and so on.
3. Pyramid of energy:
When production is considered in terms of energy, the pyramid indicates not only the amount of energy flow at each level, but more important, the actual role the various organisms play in the transfer of energy.
The base upon which the pyramid of energy is constructed is the quantity of organisms produced per unit time, or in other words, the rate at which food material passes through the food chain. Some organisms may have a small biomass, but the total energy they assimilate and pass on, may be considerably greater than that of organisms with a much larger biomass.
ADVERTISEMENTS:
Energy pyramids are always slopping because less energy is transferred from each level than was paid into it. In cases such as in open water communities the producers have less bulk than consumers but the energy they store and pass on must be greater than that of the next level.
Otherwise the biomass that producers support could not be greater than that of the producers themselves. This high energy flow is maintained by a rapid turn over of individual plankton, rather than an increase of total mass.