Population Growth Patterns By Ben Pirro, Arkin Rao, Majed Yousif, and Elias Baldeon Biology Honors Ms. Hill

Population Population is constantly changing There are four main factors to why population is constantly fluctuating

Immigration The movement of individuals into a population from another

Births Births increase the number of population

Emigration Emigration is the movement of individuals out of a population and into another population

Deaths Size of population decreases when individuals die

Exponential Growth and Logistic Growth When resources are abundant, a population has the opportunity to grow rapidly This type of growth called exponential growth, occurs when a population size increases dramatically over a period of time Exponential growth may occur when a species moves to a previously uninhabited area Most populations face limited resources and thus show a logistic growth rate During logistic growth, a population begins with a period of slow growth followed by a brief period of exponential growth before leveling off on a stable size

Exponential Growth Logistic Growth The doted line on the logistic growth chart, is the carrying capacity.

Population The Carrying Capacity The Maximum amount of individuals of a particular species that and environment can usually consistently hold A Population Crash a dramatic decline in the size of a population over a short period of time Carrying capacity can change when the environment changes The actual Population is higher or lower than what the carrying capacity actually is

Ecological factors limit population growth Limiting factor has the greatest effect in keeping the size of population down. There are two categories of limiting factors, density dependent and density independent Density-dependent limiting factors- reduce population growth with an impact that depends on current population size. Density dependent limiting factors include different species interactions

Density-dependent limiting factors Competition- individuals from a population compete with each other for food and shelter. When the population grows, the resources are being used up which limits the population growth Predation- The population of a predators can be limited by the available prey, and the population of the prey can be limited by being caught for food Parasitism and disease- Parasites and diseases are spread fast through big populations. The bigger the population, the easier they can spread. This causes the population to decrease

Predation

Density-Independent Limiting Factors Density-independent limiting factors are the aspects of the environment that limit a population’s growth regardless of the density of the population Unusual Weather- weather can affect the size of a population regardless of its density Natural Disasters- volcanoes, tsunamis, tornados, and hurricanes can wipe out populations regardless of its density Human Activities- human activities can greatly affect the ecosystem. Some examples are pollution and lumber sales

Human Activities Unusual Weather Natural Disasters

Works Cited http://www.dreamstime.com/royalty-free-stock-image-population-growth-graph-white-background-image31765396 https://filipspagnoli.wordpress.com/2010/12/09/the-causes-of-wealth-inequality-12-immigration/ http://www.pinterest.com/pin/25684660349038607/ http://www.workhouses.org.uk/emigration/ http://eofdreams.com/death.html http://math.tutorvista.com/algebra/exponential-growth.html http://biology.unm.edu/ccouncil/Biology_112/Summaries/Pop_Growth_and_Reg.html http://scienceaid.co.uk/biology/ecology/images/predpreygraph.png http://news.thomasnet.com/IMT/2012/10/25/report-industry-is-main-culprit-of-pollution-problems-in-developing-countries/ http://news.nationalgeographic.com/news/2011/03/pictures/110315-nuclear-reactor-japan-tsunami-earthquake-world-photos-meltdown/ http://www.regency-group.com/blog/be-prepared-michigan-tornado-season