A model sea has three groups. The phytoplankton have 5 g in each square metre, and they are made…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A model sea has three groups. The phytoplankton have in each square metre, and they are made again times in a year. The zooplankton have and are made again times in a year. The fish have and are made again times in a year.
- How much new matter do the phytoplankton make in a year, in g for each square metre?
- How much do the zooplankton make?
- How much do the fish make?
- Is the pyramid of biomass upright or inverted? Is the pyramid of production upright or inverted?
Need a reminder? The key ideaShow
The pyramids of number, biomass and energy have the producers at the base. The pyramid of number of a tree and the pyramid of biomass of the sea can be inverted. The pyramid of energy is always upright. Production in a year is the biomass times the turnover.
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. Biomass , , . Turnover , , times in a year.
Plan. Multiply the biomass by the turnover. Then compare.
Step 1. (a) .
Step 2. (b) .
Step 3. (c) .
Step 4. (d) The biomass is , , from the bottom up. It rises, so the pyramid of biomass is inverted. The production is , , . It falls, so the pyramid of production (energy) is upright.
Answer: ; ; ; biomass inverted, production upright.
Check. The energy pyramid cannot be inverted, as the numbers show.
Discussion (0)
Log in to join the discussion.
Loading…