If we think of nature itself and all living beings that inhabit it, there is a large network of interactions between species, and between species with their environment. In order to study these complex interactions, it is first necessary to study the populations separately, this is thanks to the ecology of populations or demology. Once we know the structure and dynamics of populations, one more step can be taken and study that complex network that we mentioned before.
If you want to know in more detail about What is populations or demologythe types of populations, as well as the demographic parameters used for this study, continues to read this Ecology Verde.
What is populations or demology
The Definition of ecology He has suffered many modifications over the years, but perhaps the most complete is the one that Margalef gives in 1978 that defines ecology as “the science that studies the systems at a level in which, the complete organisms (or individuals) can be considered elements of interaction, both among them and with the environmental matrix.” Learn more about this science with these other ecology articles about the history of ecology and what is environmental and its difference with ecology.
Therefore, knowing this definition, the Population ecology It is nothing other than that Branch of Ecology that is dedicated to Population studytaking into account its dynamics and structure. Know more about this and other branches of this science in this other post about what are the branches of ecology and what each one studies.
Types of populations
When we talk about population in ecology We refer to all those individuals that belong to the same species and who occupy a certain geographical region in the same period of time. Individuals who are part of a population are equal: the life cycle they present is the same, all their processes and the way they interact with the environment and, in addition, among them there is exchange of genetic information.
To better learn about populations, you also have to study their behavior with the environment and other species. There are different Types of populations:
- Family populations: They are those that are related to each other. Wolf herds or even the family formed by humans are examples of this type of populations.
- GREGARIAS POPULATIONS: They are those that go together for mobilization as can be in migrations or to get food, they do not have to be related. This happens for example in fish banks.
- Social populations: They are hierarchical populations, which work in an organized way since it would be difficult for them to survive if they were independent. A very clear example of this type of population is seen in bees.
- Colonial populations: Formed by those individuals who reproduce by asexual reproduction, that is, all start from the same parent. These always remain together. An example is corals, bacteria, algae, among others.
Population ecology: examples
For him Study of populations in ecology different characteristics and processes are taken into account:
- Size: refers to the number of individuals in the population.
- Density: This property refers to the number of individuals of a species that occupies a surface or volume in a certain time.
- Demographic parameters: They are the birth rate, mortality rate, immigration rate and emigration rate. These parameters are those that in number of individuals in populations change as time passes.
- Birth rate: They are those individuals born per unit of time.
- Mortality rate: They are those individuals who die per unit of time.
- Immigration rate: Individuals of the same species that come from another habitat and enter the population in the population.
- Emigration rate: are those individuals who leave the population since they move to another habitat.
- Population growth rate: This is only the result of the number of individuals that every moment, after having analyzed each of the demographic parameters. To represent population growth, models are used, the simplest and most known is the exponential growth model.
- Distribution pattern: Indicates how the individuals of the population are arranged in the territory they occupy, for example, they can be grouped, randomly or uniformly.
- Population structure: This property takes into account the sex of the individual, its size or age.
Population example in ecology
We will give the example of a pigeon population that is in a park, it is formed by 35 pigeons of which 21 are females and 14 are males, they have a weight of approximately 0.32 kg and have about 32 cm long. They are usually grouped or uniform. This species has an exponential growth, since in some areas it is even considered plague and invade the habitat of other species.
Relationship between populations, community and ecosystem
In the natural environment everything is in one related way or another, since we are talking about an open system. We have explained that the Population ecology It is the science that studies both the structure and dynamics of populations. The Ecology of communities It is something similar, but this studies the structure and dynamics between different populations that live in the same habitat in the same period of time. So, a community is that formed by populations of different species that interact with each other and the environment in which they live. Therefore, the members of a community or biocenosis and the physical environment where the relationships between them (Biotope) will be the components that form the biological system called ecosystem.
Learn more about the ecological community: definition and characteristics with this other Ecology Verde article.
If you want to read more articles similar to What is populations or demologywe recommend that you enter our category of other ecology.
- Busch, M. 2017. General ecology. Introduction to populations ecology.
