ESS formulas and calculations

Question 1

What is the formula for energy efficiency?

Answer 1

Energy efficiency = (Energy output/energy input) x 100

Question 2

What is the formula for net primary productivity?

Answer 2

NPP = GPP - R

Question 3

What is the formula for gross secondary productivity?

Answer 3

GSP = Food eaten - faecal loss

Question 4

What is the formula for net secondary productivity?

Answer 4

NSP = GSP - R

Question 5

What is the formula for the lincon index?

Answer 5

N = (n1 x n2) / m2

Question 6

What do N, n1, n2 and m2 represent in the lincon index?

Answer 6

N = Total population.

n1 = Number of animals marked in the first trial.

n2 = Number of animals recaptured.

m2 = Number of animals.

Question 7

What is the formula for simpson’s diversity index?

Answer 7

D = (N x (n-1)) / (sum of n(n-1)).

Question 8

What is the formula for crude birth rate?

Answer 8

CBR = (Number of births / population) x 1000

Question 9

What is the formula for infant mortality rate?

Answer 9

IMR = (Number of deaths of children < a year old / Number of live births in the same year) x 1000

Question 10

What is the formula for crude death rate?

Answer 10

CDR = (Deaths in one year/ total population) x 1000

Question 11

What is the formula for natural increase rate?

Answer 11

NIR = (CBR - CDR) / 10

Question 12

What is the formula for doubling time?

Answer 12

DT = 70/NIR.

Question 13

What is the critical value for total fertility rate?

Answer 13

2.2

Question 14

What is the unit when expressing productivity?

Answer 14

Mass per meter per year

gm^-2 y^-1