Fourth grade biologists created forest floor ecosystems in collaborative teams. The biotic and abiotic factors in the ecosystem are interdependent. There is a community of pill bugs, beetles, and worms living in the ecosystems, each with its own niche. Students had the choice of grass seeds and two types of ground cover to add to the ecosystem. Other available materials included organic soil, sticks, decaying pieces of wood, leaf litter, pine cones, gravel, and pebbles. We designed our ecosystems on dry erase boards before we went “shopping” for supplies. They decided as a team how much water to add, where to place the ecosystem in their homeroom, and a name for their ecosystem. Their assignment is to maintain the ecosystems, so that the populations of organisms thrive. Click here to learn more about ecosystems.