Population in terms of number is not always a necessary parameter to measure population density. Justify with two examples.

Question

(a) In a pond there were 200 frogs. 40 more were born in the year. Calculate the birth rate of the population.

(b) Population in terms of number is not always a necessary parameter to measure population density. Justify with two examples.

Answer 1

(a) Birth rate = No of individuals born Total no of individuals = 40 /200 = 0.5 frogs per year.

(b) Number is not always a necessary parameter to measure population density.

Example:

1. If there are 200 Parthenium plants but only a single huge banyan tree with a large canopy, the population density of banyan is low relative to that of Parthenium which amounts to underestimating the enormous role of the Banyan in that community. In such cases, the per cent cover or biomass is a more meaningful measure of the population size.

2. In a dense laboratory culture of a microbial population in a petri dish, the total number of microbes is again not an easily adoptable measure because population is huge, counting is impossible and time-consuming.