Topic 4: Effect of Density Population

List two reasons why clumped dispersion is commonly seen in nature.

- people survive better when they live with others - a group of people is better at defending something than one person

What is the difference between the size of the population and its density?

- size: just how many organisms are in a population- density: the number of individuals per unit area

What happens to resources as a population grows in a. logistic growth model?

- the per capita rate of increase approaches zero as the population size nears its carrying capacity- The density of individuals exceeds the system's resource availability

logsitic growth

-growth model that assumes there are limiting resources -looks like an "s" on a graph -s given by rN(k-n/k)

Research one species that represents an example of logistic population growth. Describe the species

The Arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small species of fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome.[1][8][9][10] It is well adapted to living in cold environments, and is best known for its thick, warm fur that is also used as camouflage. It has a large and very fluffy tail. In the wild, most individuals do not live past their first year but some exceptional ones survive up to 11 years.[11] Its body length ranges from 46 to 68 cm (18 to 27 in), with a generally rounded body shape to minimize the escape of body heat.

Population

group of individuals of the same species that live in the same area

Density

mass/volume

Dispersion

the pattern of spacing among individuals within the boundaries of the population

Population ecology

the study of factors that cause populations to increase or decrease

In terms of the human population, how can ecologists use demographic analysis and the prediction of future population growth to help governments/ schools/hospitals/ etc prepare for needs?

they can use them to predict how the population will grow in the future, which can signal how quickly these buildings need to expand and stock up on additional resources

What are the three dispersion patterns? Draw an illustration of each.

uniform, clumped, random