NCERT gives the annual net primary productivity of the whole biosphere as about 170 billion tons of…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
NCERT gives the annual net primary productivity of the whole biosphere as about billion tons of dry matter. The oceans, which cover about of the surface, make about billion tons of it.
- How many billion tons does the land make?
- What per cent of the total do the oceans make? Give the answer to one decimal.
- For each unit of area, how many times more NPP does the land make than the ocean? Give the answer to one decimal.
Need a reminder? The key ideaShow
, where is the respiration of the plants. Productivity is a rate, in or . The NPP is the biomass available to the herbivores and the decomposers. One kilocalorie is .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. Total , ocean , in billion tons a year. The oceans cover of the surface, so the land covers .
Plan. Subtract for the land. Divide for the share. For the area, divide each NPP by its share of the surface.
Step 1. (a) billion tons.
Step 2. (b) .
Step 3. (c) Land: . Ocean: . The ratio is .
Answer: billion tons; ; times.
Check. The ocean makes less than a third of the NPP on of the area, so the land must be several times more productive for each unit of area.
Discussion (0)
Log in to join the discussion.
Loading…