Bio-Teen May. 2014 | Page 10

Populations: Limiting factors BY:Justin marquez

In the natural world, limiting factors like the availability of food, water, shelter and space can change animal and plant populations. Other limiting factors like competition for resources, predation and disease can also impact populations. If any of the limiting factors change, animal and plant populations change, too. When a population grows larger competition, predation, parasitism and disease affect the population more strongly; all these factors are density-dependent limiting factors. Density independent limiting factors are unusual weather, certain human activities and seasonal cycles.

Limiting factors causes populations to growth to decrease. Limiting factors are split into two different terms such as Density-Dependent limiting factors and Density-Independent factors.

Density-Dependent Limiting Factors are factors that depend on a population’s size. This occurs when an amount of organisms in a given area reach a certain level. Density Dependent limiting factors include competition, predation, parasitism and disease. Competition usually occurs when the growth of a population is increases, when food is scarce, water is rare and space limited. Predation regulates populations and takes place within a predator-prey relationship. Parasitism can also limit a population they can range down to microscopic.

Density Independent Limiting Factors attack all populations in many different ways. In this case population size does not matter it will affect all sizes of populations. Unusual weather, natural disasters, seasonal factors, and certain human activities are examples of density independent limiting factors. Droughts, storms and hurricanes can extremely affect a species environment and population. Humans are big cause of many species and populations declines as; man continues to cut forests down and damming rivers which sometimes make the area inhabitable to species. Limiting factors show us the causes and problems populations go through. Especially when they are too large or they just simply undergo density independent limiting factors with weather and natural disasters. As populations grow to a extensive amount they will go through the density dependent factors will decrease the size and eventually level out or it would lead to extinction.