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Density Dependent vs Density Independent
Population growth is carefully being watched and studied by every nation in the world. This is because any changes in the number of inhabitants can have a very huge effect on a country’s economy as well as on the environment.
Population growth is not only observed in the human population but also in the population ecology of both plants and animals. The analysis and study of population growth is important for the balance of the ecosystem.
Several factors are utilized to see if the Earth can sustain its population growth despite the extinction of several species and the overpopulation of some. There are two factors that are important in determining how a certain population grows or decline; density dependent factors and density independent factors.
Density dependent factors are those that are responsible for regulating the population in proportion to its density such as competition, predation, and diseases. It usually operates in a large population and causes the population either to increase or decrease depending on how it affects the ecosystem.
For example, a huge population can deplete an area’s natural resources and food supply. This will cause a shortage of these necessary elements making the area unable to provide for its population and will eventually cause the reduction of the area’s population due to hunger, thirst, and exposure to the elements when shelter is not available.
Density independent factors, on the other hand, are those that regulate the population without considering its density such as natural disasters and the weather. It operates in both large and small populations and is not based on population density.
Natural disasters like floods, fires, storms, droughts, extreme temperatures, and the disturbance and disintegration of the natural habitat of organisms can cause a decrease in their population no matter how large or small it is. Bush fires can cause damage to the habitat of several animal species. Some may die directly due to the fire, but others who will survive it will also die because of food and water inadequacy as well as the absence of shelter for them.
Density independent factors act on their own and do not change according to its density unlike density dependent factors which vary according to the population density which depends on its gain rates and loss rates.
Both density dependence and density independence may occur together in the process of determining and analyzing population growth. Density dependence may be tested through analyzing the relationship between the growth rate and density of a certain population.
1.Density dependent factors are those that regulate the growth of a population depending on its density while density independent factors are those that regulate population growth without depending on its density.
2.Examples of density dependent factors are food, shelter, predation, competition, and diseases while examples of density independent factors are natural calamities like floods, fires, tornados, droughts, extreme temperatures, and the disturbance of the habitat of living organisms.
3.Density dependent factors usually operate in large populations while density independent factors operate in both large and small populations.
4.Density independent factors act on their own while density dependent factors depend upon the gain and loss rates.
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