Modeling Plant Productivity
In this activity, you will compare productivity and respiration in three ecosystems. Calculate the missing values in the table, “Productivity and Respiration in Three Ecosystems” on the following page.
You will need to use the following relationships: Net Primary Productivity (NPP) = Gross Primary Productivity (P) – Plant Respiration (RP) Net Ecosystem Productivity (NEP) = NPP – Consumer Respiration (RC) Net Ecosystem Respiration (R) = RP + RC P/R = ??
Productivity and Respiration in Three Ecosystems (kcal/m2/yr) Alfalfa Field Short-Grass Prairie Deciduous Forest Gross Primary Productivity (P) 24,000 5230 27,976 Plant Respiration (RP) 9200 1778 18,200 Net Primary Productivity (NPP) Consumer Respiration (RC) 800 2379 9172 Net Ecosystem Productivity (NEP) Net Ecosystem Respiration (R) P/R
Which ecosystem has the greatest Gross Primary Productivity Which ecosystem has the greatest Gross Primary Productivity? The greatest Net Primary Productivity? The greatest Net Ecosystem Productivity? Productivity and Respiration Alfalfa Field Short-Grass Prairie Deciduous Forest Gross Primary Productivity (P) 24,000 5230 27,976 Plant Respiration (RP) 9200 1778 18,200 Net Primary Productivity (NPP) 14,800 3452 9776 Consumer Respiration (RC) 800 2379 9172 Net Ecosystem Productivity (NEP) 14,000 1073 604 Net Ecosystem Respiration (R) 10,000 4177 27,372 P/R 2.4 1.26 1.02
Which ecosystem has the highest ratio of Productivity (P) / Respiration (R)? Which has the lowest? What does a ratio of 1.00 mean? Ecosystem P/R ratio Alfalfa Field 2.4 Short-Grass Prairie 1.26 Deciduous Forest 1.02
The forest and prairie ecosystems are unmanaged, whereas the alfalfa field is managed for agricultural purposes. On the basis of the data in the completed table, what are two differences between agricultural and unmanaged ecosystems?
Productivity and Respiration Alfalfa Field Short-Grass Prairie Deciduous Forest Gross Primary Productivity (P) 24,000 5230 27,976 Plant Respiration (RP) 9200 1778 18,200 Net Primary Productivity (NPP) 14,800 3452 9776 Consumer Respiration (RC) 800 2379 9172 Net Ecosystem Productivity (NEP) 14,000 1073 604 Net Ecosystem Respiration (R) 10,000 4177 27,372 P/R 2.4 1.26 1.02
What source(s) of respiration has been omitted from the table What source(s) of respiration has been omitted from the table? If this (these) factor(s) were taken into account, how would the P/R ratio be affected?
How would the P/R ratio be affected by deforestation How would the P/R ratio be affected by deforestation? Burning of fossil fuels?