SUCHIT.D.NAIK

Pyramid of Number The population of each organism in a food chain can be shown in a sort of bar chart called a pyramid of numbers.

There are two types .. Upright Inverted

Upright Inverted This type of pyramid number is found in the aquatic and grassland ecosystem, in these ecosystems there are numerous small autotrophs which support lesser herbivores which in turn support smaller number of carnivores and hence this pyramid is upright.  This type of ecological pyramid is seen in parasitic food chain where one primary producer supports numerous parasites which support more hyperparasites. 

Why a pyramid of numbers can be upright or inverted? The English Channel ecosystem exhibits an inverted biomass pyramid since the primary producers make up less biomass than the primary consumers.  Pyramid ecosystem modeling can also be used to show energy flow through the trophic levels; pyramids of energy are always upright since energy decreases at each trophic level.

Pyramid of biomass how much energy is passed on at each trophic level.  a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem.

Types of BIOMASS Upright Pyramid of Biomass Inverted Pyramid of Biomass This occurs when the larger net biomass of producers support a smaller weight of consumers.  Example: Forest ecosystem.    This happens when the smaller weight of producers support consumers of larger weight.  Example: Aquatic ecosystem. 

Usually pyramid of biomass is upright Terrestrial ecosystem, the biomass of producers is the HIGHEST. In aquatic ecosystems, like marine or pond ecosystems, the pyramid is inverted…because here there are mainly phytoplankton's. using lot of food energy for their rapid multification.

Pyramid of productivity  showing the production or turnover of biomass at each trophic level. Instead of showing a single snapshot in time, productivity pyramids show the flow of energy through the food chain.

Two points to remember Ecological productivity refers… to the primary fixation of solar energy by plants and the subsequent use of that fixed energy by plant-eating herbivores, animal-eating carnivores, and the detritivores that feed upon dead biomass. This complex of energy fixation and utilization is called a food web.

Notes The rate flow of energy from producers to successive levels of consumers. During the transfer of energy considerable amount of energy is lost as HEAT. Only 10% is transferred to HERBIVORES. Always upright in all types of ECOSYSTEM.

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