Question

Which one of the following formulae correctly represents the relationship between population density and the processes that influence it?

• A. $N_{t+1}=N_t+\left[\right(B+I)+(D+E\left)\right]$
• B. $N_{t+1}=N_t+\left[\right(B+I)-(D+E\left)\right]$
• C. $N_t=N_{t+1}-\left[\right(B+D)-(I+E\left)\right]$
• D. $N_{t+1}=N_t+\left[\right(B+D)-(I+E\left)\right]$

Answer 1

The correct option is B $N_{t+1}=N_t+\left[\right(B+I)-(D+E\left)\right]$

Population density is the number of individuals per unit area at a given time. If the initial population density at time t is $N_t$, then the population density at time t+1 can be represented as

$N_{t+1}=N_t+\left[\right(B+I)-(D+E\left)\right]$

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