In a pond, there were 20 lotus plants last year. Over the course of one year, 8 new plants were added through reproduction, while 2 plants died. Additionally, 5 plants were washed into the pond from a neighbouring water body, and 1 plant was washed away. What is the final population size of lotus plants in the pond at the end of the year?

Step-by-step solution

The population size at time t+1 is given by the equation: N_ t+1 = N_ t + [(B + I) - (D + E)] Given: Initial population ( N_ t ) = 20 Births ( B ) = 8 Deaths ( D ) = 2 Immigration ( I ) = 5 Emigration ( E ) = 1 Substituting the values: N_ t+1 = 20 + [(8 + 5) - (2 + 1)] N_ t+1 = 20 + [13 - 3] N_ t+1 = 20 + 10 = 30 The final population size is 30. Calculating only the net change without adding it to the initial population gives 10. Reversing the signs for immigration and emigration gives 22. Answer: 30