A terrarium is a little ecosystem on its own that can help children learn the relationship between organisms such as plants and resources such as water and sunlight. You can house a terrarium in almost any open or closed container. Terrariums without a lid will require more water. A mason jar will work fine for a small terrarium. Fill the jar with a one-inch layer of pebbles for drainage. Add another inch layer of sphagnum moss on top of the pebbles. The moss helps keep the soil away from the pebbles. Next add a few inches of soil and plants either purchased or found outside. Make sure to place your new ecosystem in a spot where it will get sunlight, and water it regularly.
A study of food chains can help children realize how plants and animals are connected and interdependent. Use a small notebook with at least 25 sheets of paper. Draw a clump of earth on the first page. On the next few pages draw a local plant growing gradually. Next, research what kind of insect eats that plant and draw the insect eating the plant. Then draw the kind of bird that might eat the insect, and so on. Be sure to draw the pictures near the edge of the paper where they will show up as you ruffle the pages from front to back to view your fast-action food-chain flipbook.
Children can use a journal or notebook to record their own explorations of local ecosystems in their own yard or at a local park. Take a magnifying glass along and study living and nonliving things. Suggest that children take notes about the things they see, draw pictures of them and color them in when they get home. Have them note whether the animals they see show any adaptations to their environment. Are they camouflaged? Have them record the day's weather conditions and any other thoughts or observations they have.
It's important to make children aware of dangers to ecosystems. One way to do this is to explore threats like acid rain. Start with two small, healthy plants of the same size in two separate pots. Fill a spray bottle with distilled water and label it "water." Fill another spray bottle with equal portions distilled water and vinegar and label that bottle "acid rain." Label the pots "water" and "acid rain" as well. Place the plants in a sunny window, and spray them daily with their corresponding bottles. Do this for at least a few weeks. Talk to the children about the differences between the two plants and how real acid rain might affect vast ecosystems such as rain forests.