What is meant by ecological pyramid? With the help of one example each, show that the pyramid of numbers can be both upright as well as inverted.
An ecological pyramid is a graphical representation in the form of a pyramid that depicts the feeding relationship of groups of organisms. It is frequently depicted as follows: the producers are at the bottom, followed by the various trophic levels, with the highest at the top. A pyramid of numbers is a graphical representation of the number of organisms at each trophic level. In an upright pyramid of numbers, the more abundant species form the first trophic level i.e., the base of the pyramid, and less abundant species remain near the top. Example: - Grassland ecosystem In a grassland ecosystem, producers (Green plants) are more in number, and herbivores (Rabbit) are more than carnivores (Fox and Lion). In an inverted pyramid of numbers, the most abundant species occurs at the top while the less abundant species form the base of the pyramid. Example: - Tree ecosystem. A big tree provides food to several herbivores (birds) which in turn provides food to few carnivores.
