CH.+52+Population+Ecology

Chapter fifty two is all about population. Population density is the number of individuals per unit area, and population density i varied my many factors. Demography, the increase of population from births and the decrease in population from deaths, is the most common factor in population density. Other natural factors such as immigration and emigration affect population density as well. There are many equations and graphs to model populations growth and decrease. The exponential growth model plots growth will all factors and shows that as the population gets larger, reproduction happens more rapidly. Another more realistic model is the logistic growth model. This states that a population cannot exceed the carrying capacity of its environment. This model fits few populations, but creates a good estimation. Many populations have their own ways of stabilizing. Some are density dependent, and this means that when the birth rate falls the death rate increases. Populations can adjust and become stable in other ways. Some cannot survive with limited food, certain disease, crowding, predators or toxins.

Chapter 52 relates to three of the core themes of biology. Many of the traits of the population are a reflection of evolution. These traits can shape the way the species reproduces and acts in its population. Continuity and change is also present in chapter 52 because the organisms will either continue to succeed or change to become successful in competing with other populations. A las theme is regulation. The populations are regulation by the abiotic and biotic factors present in their environment.

http://www.ento.vt.edu/~sharov/PopEcol/lec5/logist.html ^^ extreme logistic growth model explanation. Very mathematical.

http://geography.about.com/od/populationgeography/a/popdensity.htm ^^ population density article, sweet facts, cool ratios about china.

http://www.gpa.unep.org/content.html?id=199 ^^ Bar graph and article about population density and destruction within countries. Really sweet.