In which of the following options, both the processes in the pair have a positive effect on population density?
In which of the following options, both the processes in the pair have a positive effect on population density?
The correct option is D Natality and immigration
Population density is the number of individuals of a species per unit area at a given time. If the initial population density at time t is Nt, then the population density at time t+1 can be represented as
Nt+1 = Nt + [(B+I)-(D+E)]
Where,
B is natality i.e. number of births during a given time period
I is immigration i.e. number of individuals of the same species that enter a population from elsewhere during a given time period
D is mortality i.e. number of deaths during a given time period
E is emigration i.e. number of individuals of the same species that leave a population during a given time period.
Both natality and immigration add individuals to a population and have a positive effect on the population density whereas, mortality and emigration deduct individuals from a population and have a negative effect on it.
Population density is the number of individuals of a species per unit area at a given time. If the initial population density at time t is Nt, then the population density at time t+1 can be represented as
Nt+1 = Nt + [(B+I)-(D+E)]
Where,
B is natality i.e. number of births during a given time period
I is immigration i.e. number of individuals of the same species that enter a population from elsewhere during a given time period
D is mortality i.e. number of deaths during a given time period
E is emigration i.e. number of individuals of the same species that leave a population during a given time period.
Both natality and immigration add individuals to a population and have a positive effect on the population density whereas, mortality and emigration deduct individuals from a population and have a negative effect on it.
