Use a large, shallow bowl for a desert ecosystem. Layer the bottom of the bowl with pebbles that are covered with sandy soil. Cacti and aloe vera will grow well in this type of terrarium. Desert plants do not need very much fertilizer or water. Use a tank that is designed for reptiles, if you wish to include lizards or snakes in this ecosystem. The reptiles will need to be given food and water every day.
A quart jar can be used to make a coniferous ecosystem. Place a layer of sandy soil in the bottom and some pine needles. Add small ferns, pinecones and a stick that has a cluster of pill bugs and centipedes on it. Use a small nail to make holes in the lid before placing it on the jar. This type of terrarium is great for a day or two while camping and enjoying the woods.
A mini pond garden requires very little work. Any vessel that holds water can be used for a patio pond. Specially designed containers for miniature water gardens are available at garden centers. Fill the container with rainwater, and add plants on the ledge inside the bowl or at the bottom of the bowl. A small fountain or aquarium pump will help to aerate the pond. Adding fish may complete the ecosystem. Perhaps even a local frog may take up residency in your patio pond.
Use a gallon jar with a lid that will prevent evaporation. Pour one cup of water into the bottom of the jar to provide the moisture that will be needed for the rainforest plants. Cover the bottom of the jar with a layer of aquarium stones followed by a layer of charcoal. Add a layer of soil that is used for propagating African violets. African violets and aluminum plants will grow well in this ecosystem. Carnivorous plants can be added to this ecosystem. Insects will need to be added to the terrarium to feed these plants.