That’s more than 8.74 million species that have been described, not including bacteria. That may seem like a lot, but every species has a purpose in its ecosystems. Some species may perform the same role as others but in different environments or in different way. 

Animals include birds, invertebrates, insects, mammals, reptiles, amphibians, and fish, which support other organisms in their ecosystem through seed dispersal, pollination, being a food source, regulating population sizes, decomposing organic matter, and recycling nutrients to name a few.

Plants & algae, called photosynthetic autotrophs (they create their own energy through photosynthesis), create consumable energy and oxygen, which supports the existence of every living animal as well as some bacteria and fungi species.

Fungi are like an ecosystem’s digestive tract; they decompose and recycle nutrients and organic matter into forms plants can utilize. They form an underground network that connects plants, transferring nutrients from one plant to another and storing carbon underground that plants pull from the atmosphere during photosynthesis.

Bacteria exist almost everywhere on the planet and fulfill a wide range of ecosystem roles in a multitude of ways. They can be producers in the depths of the ocean, where they use naturally occurring chemicals to create energy, or closer to the surface and on land, where they photosynthesize similarly to plants and algae. They decompose organic matter and continue the cycle of carbon and nutrients into forms that plants can use. They also fix nitrogen, which is a vital ingredient for energy production and storage in plants.