What’s For Dinner?
Sharing Energy in the Food Web

Plants Capture the Sun’s Energy

Chlorophyll is the main substance on Earth that can capture the energy in sunlight and store it. It is in all green plants. Chlorophyll allows plants to turn the sun’s energy into building blocks to build their bodies. These building blocks are called carbon molecules. They are too small to see (even with a microscope) but all plants and animals are made from them.

This is a common species of algae in the vernal pools, Zygnema. This is how it looks through a microscope – about 40 times bigger  than it would appear to the naked eye. Notice the tiny cells all  connected in long chains. The green color comes from chlorophyll.

Cycling Energy through the Food Web

Plants are the foundation of the food web. The energy stored in plants is the main source of energy in a food web. When animals or plants die, the energy is locked up in the detritus, waiting to be recycled by the bacteria and protozoa again. It is a cycle that never ends as long as all the species in the food web survive.

Example Food Web

This simple food web shows how energy moves from one species or group to the next. Many connections among species are unknown, because vernal pool food webs have not been well studied. The species in a food web are grouped into four levels, depending upon where their energy comes from:

  1. Dead Matter (detritus)
  2. Decomposers (bacteria)
  3. Producers (algae and other green plants that produce energy)
  4. Consumers (animals that get energy from producers or other consumers).

Which level do most of these species occupy?