Question

The net annual primary productivity of a particular wetland ecosystem is found to be 8,000 kcal/m2 per year. If respiration by the aquatic producers is 12,000 kcal/m2 per year, what is the gross annual primary productivity for this ecosystem, in kcal/m2 per year?
A. 4,000
B. 8,000
C. 16,000
D.20,000
E. 96,000

Answer 1

Answer:

D.20,000

Explanation:

The Gross Annual Primary Productivity for the wetland ecosystem is the amount of carbon taken up by the aquatic producers through photosynthesis.  

Given that: Net Annual Primary Producer is 8,000 kcal/m2 per year, and respiration by the aquatic producers is 12,000 kcal/m2 per year, using the formula NPP = GPP – Respiration, we can determine the Gross Annual Primary Productivity of the wetland ecosystem.

NNP = 8,000 kcal/m2

Respiration = 12,000 kcal/m2

GPP = x

8,000 = x – 12,000 (NPP = GPP – Respiration)

Solve for x:

x = 8,000 + 12,000

x = 20,000 kcal/m2 per year

GPP = 20,000 kcal/m2 per year