The frequency of spear grasses in different locations of an abandoned field is 40 After throwing a quadrant 80 times. Calculate its population size using a quadrant dimension of 1 square meter.

40

Explanation:

The population size refers to the total number of individuals in a population. It can be obtained by counting the total number of individuals in a population. In a typical plant field where it is almost impossible to count the number of individuals, the population size can be mathematically estimated using the quadrat method:

Population size =  (A/a) x n,

where A = area of the field, a = area of quadrat, and n = number of plants per quadrat.

In the illustration, the area of the abandoned field was not given. Hence, it is assumed that the area of the field is equivalent to the number of quadrat thrown. Since the size of the quadrat is 1 square meter:

Area of the field = 80 x 1 = 80 square meters.

Number of plant per quadrat = 40/80 = 0.5

Population size = 80/1 x 0.5 = 40

Therefore, the population size is 40 spear grasses.