Population Dynamics

Question 1

Def of population

Answer 1

The population is a group of individuals of the same species who live together in the same habitat and are likely to interbreed. Eg deer living on a moorland in Scottish Highlands.

Question 2

Population density

Answer 2

There are four ecological events that affect the population density of a population:

1. Birth
2. Deaths
3. Emigration
4. Immigration

Change in population density= (birth + immigrants) - ( death + emigrants)

There is a limit to the size of populations that can be supported by any environment - carrying capacity

If The population exceeds the current capacity; death rates may exceed reproduction and population may crash

Question 3

Population density p2

Answer 3

The secondary events which could influence the frequency of the primary events are:

decrease in predators which can lower the death rate

a rapid increase in the winter temperatures or changing climate can increase death rates

secondary events help REGULATE the population

Question 4

Density independent factors

Answer 4

These are conditions which will affect an ecosystem regardless of the number of species within a particular area.

Decrease in the concentration of oxygen (aquatic rainfall)

Risk of fire (forest ecosystems)

Weather related events such as heavy rainfall