Exploring Earthworms- Miniature Ecosystem
Our home-schooled children have been working together to make a mini-ecosystem for earthworms, using a soda bottle and a little creativity.
As with all other organisms, earthworms occupy a certain niche: They are both decomposers and consumers, feeding on things like decomposing remains, manure, and other small underground organisms like nematodes, bacteria, fungi, and rotifers.
Earthworms breathe by coating themselves with mucus, which allows dissolved oxygen to pass into their bloodstream, so living conditions must be moist and humid, or else the worms will dry up. They are ecologically important because they loosen and mix up the soil, enabling water and nutrients to seep through to plant roots. Since they can’t walk, earthworms move with tiny bristles, or setae, which are paired on each of their segments and grip onto the worms’ tunnel walls. Then the worms push themselves forward with strong muscular contractions.
The Science experiment involved adding a range of materials to the plastic bottles (sand, mulch, soil) then placing some shredded lettuce on top of the soil which followed on by putting the earthworms only in one of the bottles. Both plastic bottles were then covered with aluminum foil and placed in a cool place away from sunlight. Children were instructed to check the bottle ecosystem every day over the next week and to keep the soil moist and ass more lettuce as needed.
Exploring this topic helped the children to understand important things about ecosystems and nature. Their investigations included comparing what happened to the lettuce in the two ecosystems, what happened to the soil layers as well as identifying how earthworms benefit the soil. The children realized how important earthworms are for not just underground life, but also for the plants and trees that are also important for our environment.