By zooming in and out to examine ecosystems of all sizes, we can better understand how our natural world works. Large ecosystems are often made up of many smaller communities and ecosystems that sometimes even have their own microclimates. The living and nonliving things that share these microhabitats may interact with life from the larger ecosystems that they are also a part of. For example, a pond, which is an enclosed ecosystem on its own, also provides drinking water and food to animals that are a part of a larger forest. Small ecosystems make larger ecosystems more stable by creating far more resources and more biodiversity. Here are two examples of microecosystems.

Scientists estimate that there are over a trillion species of microbes on Earth. Just look at a drop of water under a microscope, and you will see a whole world teeming with life. Microbes are everywhere, floating all around us; on our skin, our food, and the dirt on our shoes; and in the air we breathe. But don’t get grossed out; we need microbes more than they need us. We rely on these tiny creatures to sustain all life on Earth, from creating the air we breathe to the food we eat.

Microscopic plants called phytoplankton are the basis of the marine food web—all life in the ocean depends on them. In turn, plant life in the ocean generates over half of all the oxygen on the earth (the rest comes from terrestrial plants). As if that was not enough, microbes are also important decomposers that turn dead plants and animals into fertile soil. In this new soil, new plants grow, which in turn sustain animal and human life. Microbes and bacteria are key for the cycling of vital nutrients like carbon, nitrogen, and phosphorus throughout the global ecosystem. Without these microbes, there would be no life on Earth!

Bacteria and other microbes are often the first type of life that can colonize inhospitable areas, turning depleted wastelands into lush ecosystems that can support more life. Ecologists can use their knowledge of microorganism ecology to help revitalize areas that seem to be barren. Microorganisms may seem like they are in a world of their own, but our world would not exist without them.