Ecology: Population Changes

Question 1

How the Size of population in ecosystems is in controlled by

Answer 1

By birth/death rates as well as immigration and emigration

Question 2

Birth/Death rate

Answer 2

If birth rate exceed death rate the population increases due to more individuals
If death rate exceeds birth rate the population decreases
If both equal the population remains constant. This is know as a STABLE POPULATION

Question 3

Environment factors to population change

Answer 3

It may serve to increase/decrease birth/death rates

One major factor is food availability. If availability is high then there will be an increase rate of survival, most will reach reproductive stage of their life cycle and offspring will be born. Birth rate increases

Question 4

Population change equation

Answer 4

Birth rate + immigration - (death rate + emigration)

Most questioned don’t involve emigration and immigration
It is important to know:
No Population change, then number of births=number of deaths
Population decrease, then birth rate < death rate
Population increase, then birth rate > death rate

Question 5

Advantage of pyramids of biomass over pyramid of numbers

Answer 5

A pyramid of biomass won’t give an inverted pyramid, as they take into account the size of the organism