Population refers to the group of the organism of the same species living at the same time in the same area where the size, density, and growth of it are considered for regulation and limitation. Its growth is being carefully watched and studied by every nation around the world because any change in the number of inhabitants can have a large effect on the economy of the country. Two important factors regulate the growth or decline of the population and they are Density Dependent and Density Independent factors.
Density Dependent vs Density Independent
The main difference between Density Dependent and Density Independent is that Density Dependent regulates the population in proportion to its density whereas Density Independent regulates the population without considering its density.
Density Dependent is responsible for regulating the population in proportion to its density such as prediction, competition, or disease. It generally causes the population to either decrease or increases depending on how it affects the ecosystem and operates in a large population.
Density Independent are those that regulate the population without considering its density such as natural disasters and the weather. The measurement of population control operates small as well as large populations and is not bored on density. Natural disasters such as storms, drought, floods, extreme temperature, fire, and distinction of organisms can cause a decrease in their population.
Comparison Table Between Density Dependent and Density Independent
| Parameters of Comparison | Density Dependent | Density Independent |
| Definition | Density Dependent is responsible for regulating the population in proportion to its density such as prediction, competition, or disease. | Density Independent are those that regulate the population without considering its density such as natural disasters and the weather. |
| Size of Population | Density-dependent generally operates in a large population. | Density Independent operates in both Small and large populations. |
| Action | It depends upon the gain and loss rate. | Density Independent acts on their own. |
| Factors | The factors of Density-dependent are food, shelter, prediction, competition, and disease. | The factors of Density Independent are flood, fire, drought, extreme temperature, and tornados. |
What is Density Dependent?
Density Dependent is one of the factors/measures of regulating population growth considering the density of the population such as prediction, competition, and disease. Its regulation can be affected by the factors that affect the birth and death rate such as competition and predation. It can also be affected by other factors such as abiotic factors and environmental factors such as uncertain weather and conditions such as a fire.
In ecology, density-dependent factors are also known as regulating factors. Any force that affects the size of a population of living things which often arises from biological phenomena, rather than chemical or physical phenomena. It is called regulating factors because they maintain population density within the narrow range of value.
Some diseases spread faster, in a population where individuals live near each other rather than who lives apart. Therefore, the density of that particular population decreases, through mortality or migration, decreasing the influence of density-dependent factors.
The liveliness of most population of living things are influenced by a combination of factors of density-dependent and the relative effect of the factors vary among the population of all kind of living organism.
What is Density Independent?
Any factor that affects the size of a population of living things regardless of the density of the population which often arises from chemical and physical phenomena is known as density Independent. It is also called a limiting force in ecology.
Disasters such as floods, famine, landslides, climate change, wildfire affect a population of living creatures whether individuals are clustered close together or spread far apart. Most of the living organisms breathe oxygen, oxygen availability is a density-independent factor. Therefore, if oxygen concentration declines or breathable oxygen suddenly made unavailable then those organisms perish and the population of the various affected organisms will decline.
Pollutants contribute essentially to environmental stress, restricting the growth rates of populations. Every species including amphibians has specific tolerances for environmental toxins and is particularly susceptible to environmental pollutants. Since Endocrine-disrupting toxins can control the growth of amphibians, it results in restriction of population growth irrespective of the size of the amphibian population. Apart from pesticides, these also include herbicides, fungicides, thermal pollution and heavy metal contaminations, etc.
The liveliness of most populations of living beings is influenced by a combination of factors of density independence and the relative importance of these factors varies from species to species and from population to population.
Main Differences Between Density Dependent and Density Independent
- Density Dependent is responsible for regulating the population in proportion to its density such as prediction, competition, or disease. On the other hand, Density Independent are those that regulate the population without considering factors like weather and natural disasters.
- Density-dependent generally operates in a large population. As against, Density Independent operates in both Small and large populations.
- Density-dependent depends upon the gain and loss rate. Whereas, Density Independent acts on their own.
- The factors of Density-dependent are food, shelter, prediction, competition, and disease. On the other hand, The factors of Density Independent are flood, fire, drought, extreme temperature, and tornados.
Conclusion
The growth of population is being properly studied and watched by every nation around the world because any change in the number of inhabitants can have a very vast effect on countries economy and the environment.
Several factors are used to see if the earth will be able to sustain the population growth. Additionally there is an ongoing extinction of species.
References
- https://www.nrcresearchpress.com/doi/abs/10.1139/f07-111
- https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0706.2008.16872.x