between the numbers?Is there any
comparison that could be made about the
sizes of the organisms involved at each
stage.
The number of organisms in a food chain
can be represented graphically in a pyramid.
Each bar represents the number of
individuals at each trophic level in the food
chain. At each link in a food chain, from
the first-order consumers to the large
carnivores, there is normally an increase
in size, but decrease in number. Let us
observe fig-5, for example in a forest, the
aphids are very small and occur in astronomical numbers, the ladybirds
which feed on them are distinctly larger and not so numerous, the
insectivorous birds which feed on the ladybirds are larger still and are
only present in small numbers, and there may only be a single pair of hawks
of much larger size than the insectivorous birds on which they prey. This
relationship is best shown as a pyramid, which is upright.
Draw the pyramid of number for the following food chains
(i) Banyan tree insects Woodpecker
(ii) Grass rabbit wolf
Do the pyramid of numbers have the same structure in both the
cases when compared to the example given in the previous para-
graph?
If there is a difference then what is it?
Sometimes the pyramid of numbers does not look like a pyramid at
all. This could happen if the producer is a large plant such as tree or if one
of the organisms at any trophic level is very small. So keep one thing
always in mind that whatever be the situation, the producers will be at the
bottom of the pyramid.
Pyramid of Biomass
What is biomass?
Biomass is organic material of biological origin that is ultimately
derived from the fixation of carbon dioxide by trapping solar energy during
photosynthesis. This includes trees, shrubs, crops, grasses, algae, aquatic
