Ecological Pyramids

Ecological Pyramids
An Ecological Pyramid (Trophic pyramid) is a graphical representation designed to show the relationship between energy and trophic levels of a given ecosystem. Most commonly, this relationship is demonstrated through the number of individuals, the amount of biomass, or the amount of energy at a given trophic level. All Ecological Pyramids begin with producers on the bottom and proceed through the various trophic levels, the highest of which is on top.There are 3 types of ecological pyramids:
1. Pyramid of numbers.
2. Pyramid of biomass.
3. Pyramid of energy
1- Pyramid of Numbers
The pyramid of numbers depicts the relationship in terms of the number of producers, herbivores and the carnivores at their successive trophic levels. There is a decrease in the number of individuals from the lower to the higher trophic levels. The number pyramid varies from ecosystem to ecosystem. The following shape is shows typical pyramid of numbers:
There are three of pyramid of numbers:
• Upright pyramid of number
• Partly upright pyramid of number or( spindle- shapped number pyramid).
• Inverted pyramid of number.
Upright Pyramid of Number
This type of pyramid number is found in the aquatic and grassland ecosystem, in these ecosystems there are numerous autotrophs which support lesser herbivores which in turn support smaller number of carnivores and hence this pyramid is upright because of with each higher trophic level, the number of individual decreases.