Ecological Pyramids -

Graphical representation of the Ecological Parameters like Numbers, Biomass, Energy is called as the Ecological Pyramids.

Pyramid was first of all made by the Charls Elton; so this pyramids are also known as Eltonian Pyramids.

There are 2 types of pyramids

1.

                         

2.

the 2 no pyramid gives more accurate data so we use 2 no. pyramid in this post.

This are also of 2 types upright and inverted.

UPRIGHT PYRAMID

INVERTED PYRAMID

Pyramids of Number-

When the number of trophic levels are arranged on the basis of number in the systematic manner then it forms the pyramid of number.

Pyramid of Number in Grassland Ecosystem-

The pyramid is made on the basis of Grazing Food Chain like-

 Grass → Rabbit  → Wolf  → Lion

It is the Upright Pyramid as the number of grasses are more than the no. of rabbit and the number of organism gradually decreases with increase in the trophic level.

Pyramid of Number in Aquatic Ecosystem-

Based on the food chain-

Phytoplanktons  → Zooplanktons  → Small fish  → Large fish 

note : large fish may be shark if the aquatic ecosystem is the ocean.

Pyramid of Number in Tree Ecosystem-

Tree  → Birds  → Parasites 

Parasite may tick, lice, etc.

This Pyramid is inverted as the number of tree we are considering for tree ecosystem is 1.

Pyramid of Number in the forest-

PP (Trees, Herbs, Shrubs, etc)  → PC (may be rabbit, deer, mice etc)  → SC (Wolf, Snake, etc)  →TC (lion, Peacock, etc)

It is mostly upright as the Primary Producer in the forest is more in the number because the grasses, herbs, are more in the forest than PC.

But in the Tree Dominating Forest the pyramid is same as the tree ecosystem pyramid that is Inverted.

Pyramid of the Biomass-

Pyramid made on the basis of the biomass of the trophic levels of the food chain.

Note : The Biomass we use here is always the Dry Weight of the organism.

Dry weight is the more accurate weight but the fresh weight may vary on the basis of the water.

In Grassland Ecosystem-

Grass (120 kg)  → Rabbit (80 kg)  → Wolf (60 kg)  → Lion (20 kg)

Upright pyramid of the Grassland.

In Tree Ecosystem-

Tree (100 kg) → Birds (5 kg)  → Parasites (1/4 kg)

Pyramid of biomass on the Tree

In Aquatic Ecosystem-

a. Ocean

Phytoplanktons (10 kg)  → Zooplanktons (15 Kg)  → Small Fish (60 kg)  → Large Fish (100 kg) (Shark)

Dry Weight of the Phytoplanktons is very less because they are the unicellular organism so have less mineral content in them.

and weight of the large fish is maximum because in ocean large fish shark.

Pyramid of the Ocean 

b. Lake

Phytoplanktons (5 kg)  → Zooplanktons (8 Kg)  → Small Fish (50 kg)  → Large Fish (15 kg)

let assume the small fish in the pond is 100 and each of 1/2 kg then the overall mass will be 50 kg

and large fish in the pond is 3 each of 5 kg then the mass will be 15 kg.

In lake ecosystem the pyramid formed will be Spindle shape.

Spindle shape pyramid of the Lake Ecosystem.

Spindle Shape Pyramid of lake.

c. Pond

Phytoplanktons (2-3 kg)  → Zooplanktons (5 Kg)  → Small Fish (8-10 kg)

Pyramid of the lake.

NOTE : All the values used above are the assumed values and where taken for the small area.

Pyramid of Energy-

Pyramid of the Energy is always upright. 

As the only 10 %  energy is transferred from one trophic level to another so energy at higher trophic level will always be less than the lower trophic level.

So, to conclude most of the Ecological Pyramids are Upright in the nature excepts the 2 PYRAMID OF NUMBER IN THE TREE ECOSYSTEM  and  PYRAMID OF BIOMASS IN AQUATIC ECOSYSTEM    which are inverted in nature.