The organisms and habitat together form what we call an ecosystem. Ecosystems can vary greatly in size. From tiny microorganisms to large landscapes, ecosystems allow the earth’s living things to survive and thrive.
Ecological balance is a state of dynamic equilibrium within a community of organisms in a habitat or ecosystem. Dynamic means that there is constant change and variety in the relationships between the organisms and their environment.
Gradual changes do take place but that happens only through natural succession. It can also be explained as a stable balance in the numbers of each species in an ecosystem. This occurs through competition and cooperation between different organisms where population remains stable.
This balance is brought about by the fact that certain species compete with one another determined by the environment in which they grow. This balance is also attained by the fact that some species depend on others for their food and sustenance.
Such accounts are encountered in vast grasslands where the herbivorous animals (deer, zebras, buffaloes, etc.) are found in plenty. On the other hand, the carnivorous animals (tigers, lions, etc.) that are not usually in large numbers, hunt and feed on the herbivores, thereby controlling their population.
In the plants, any disturbance in the native forests such as clearing the forest for shifting cultivation usually brings about a change in the species distribution.
This change is due to competition where the secondary forest species such as grasses, bamboos or pines overtakes the native species changing the original forest structure. This is called succession.
