Population Ecology Theory
- Thomas Malthus, who published a report that described the population’s relationship to natural resources, formed the earliest theory of population ecology. Charles Darwin extended this with his “survival of the fittest” concepts.
- In history, ecology depended upon the concepts of other areas of study. One scientist, Alfred James Lotka, changed the science practice when he came up with the origins of population ecology. Lotka pursued the formation of a new field of “physical biology” in which he included a systems strategy for studying the relationship between organisms and the environment.
- Biostatistician Raymond Pearl took note of Lotka’s work and united with him to discuss predator-prey interactions.
- Vito Volterra, an Italian mathematician, started investigating predator-prey relationships in the 1920s. This would lead to the Lotka-Volterra equations that acted as a springboard for mathematical population ecology.
- Australian entomologist A.J. Nicholson led the earlier fields of study about density-dependent mortality factors. H.G. Andrewartha and L.C. Birch would go on to explain how abiotic factors impact populations. Lotka’s systems method to ecology still influences the field to this day.
Density-dependent population regulation
When population ecologists examine the growth of a population, it is via the lens of factors that are density-dependent or density-independent. Density-dependent population regulation represents a strategy in which a population’s density impacts its growth rate and mortality. Density-dependent regulation manages to be more biotic. For example, competition within and between species for resources, diseases, predation, and waste buildup represents density-dependent factors. The density of available prey would also impact the population of predators, causing them to move or potentially starve.
Density-independent population regulation
Density-independent population regulation refers to natural (physical or chemical) factors that impact mortality rates. In other words, mortality is affected without considering density.
These factors, such as natural disasters (e.g., wildfires and earthquakes), lead to being catastrophic. Anyway, Pollution is a man-made density-independent factor that affects many species. The Climate Crisis is another instance.
Population Ecology – Definition, Characteristics, Importance, Effects
Ecologists study how organisms interact with their surroundings on earth. Population ecology is a more specific field of study of how and why the populations of those organisms transform over time. As the human population rises in the 21st century, the information gleaned from population ecology can help with planning. It can also help with measures to preserve other species.