How do you build a mini ecosystem?

It will be built inside a container that's about 30cm by 30cm by 20cm. Once finished, it will be sealed with a lid forever. It has to be sustainable, viable, and reasonable.

Re-design7 years ago
A little water, some dirt, some plants, right temperature and regular sunlight is about all it takes. But you're never going to be able to get inside yourself. I've had them live for over a year in a gallon pickle jar. It was still living I just got tired of it.
That's what some of my pupils did, in a large sweet-jar lying on its side. They included a small pool of water by piling all the solid bits at the bottom end of the jar (soil, moss, wood). They also added a few woodlice and small snails. They sealed the lid with stickytape, and left it on the windowsill of my lab for about six months, until the school year ended and a pupil took it home. It was very interesting to watch different plants come to dominate the little space as the system got used to being enclosed.