Answer: The density-dependent limiting factors that are usually biotic and include
--> migration of organisms to other habitats
--> invasion and colonization by new species and
--> increase or decrease in birth rates and death rates.
Explanation:
Population density in an ecosystem is defined as the average number of individuals of a species per unit area of the habitat. It can be used to estimate the total number of individuals of a population, that is population size, in a habitat in the following way:
Density × Area of habitat = Population size
For any population, there is an optimum density that can be reached in a given habitat under the operating environmental conditions. Population in a habitat often show changes especially in SIZE and distribution. These are due to biotic limiting factor such as:
--> migration of organisms to other habitats
--> invasion and colonization by new species and
--> increase or decrease in birth rates and death rates.
These factors are known to operate during:
--> seasonal climatic changes
--> changes in food availablity
--> breeding periods and
--> unfavourable natural events such as fires and droughts.
