Populations 5-2 Limits to Growth IDENTIFY DENSITY-DEPENDENT AND DENSITY-INDEPENDENT LIMITING FACTORS THAT AFFECT POPULATIONS IN AN ECOSYSTEM.

Video clip on Limiting Factors First, we are going to watch this quick video on limiting factors! Pay attention  https://www.youtube.com/watch?v=8FPMP41LYJ8

Limiting Factors Definition- A factor that causes population growth to DECREASE Ex: Competition Predation Parasitism and Disease Drought and other Climate Extremes Human Disturbances A resource base that is limited can also affect the long-term survival of a species

Density-Dependent Factors A limiting factor that depends on population size is called a density-dependent limiting factor. In general, density-dependent factors are biological factors

Some examples of this include competition predation parasitism and disease

Density- Independent Factors Definition- This is when all populations are affected in similar ways, regardless of the population size.

Some examples of this include Unusual weather natural disasters seasonal cycles certain human activities—such as damming rivers and clear cutting forests

Activity Questions 1 & 2 1) Explain the difference between density independent and density dependent limiting factors. Density Independent Density Dependent

Activity Question 2 2) Each of the statements below involves a situation that will affect the growth of a population. Classify each of the statements as DD (density dependent) or DI (density independent) and give a reason for your choice. (18 marks - 2 each) a. Rainbow fish and yellow fish attempt to occupy the same area. The more aggressive rainbow fish survive; the yellow fish do not. b. A severe flood brings a lot of sediment and silt into a lake. The cloudiness of the lake increases greatly. c. A drought decreases the water level in a lake. The carrying capacity of the lake decreases.

Activity Question 2 d. Due to the introduction of rainbow fish, a lake becomes crowded and some fish species do not survive. e. Since northern fish prey on yellow fish, an increase in the yellow fish population causes an increase in the northern fish population. f. Many fish die due to an increase in water temperature. g. Due to over-fishing, the number of yellow fish in a lake decreases. h. A population is growing quickly when parasites cause disease to spread quickly.