Look around at the ecosystem around you. Right now, it probably includes humans, bacteria, maybe some small animals (some you can’t see), and maybe even some plants. But what you might not consider is that the non-living things also affect you, like the amount of humidity, the amount of heat, the chair you are sitting in, and the desk where you are sitting.
When we talk about biomes, climates and ecosystems, we’re talking about different ways to describe the living and non-living things around us. Climate determines the type of biome, which in turn determines the ecosystems that can exist. Inside any ecosystem, we can divide everything into two large groups: abiotic and biotic.
The biotic part of the environment is easy to understand: since “bio” means “alive”, you know that these must be the living things in the environment. All animals, plants, bacteria, fungi and protists are part of the biotic part of the environment. We also know that these living things interact with each other. Plants are often known as producers, because they take energy from the sun and turn it into usable energy for animals. Animals are often divided into primary consumers and secondary consumers. The primary consumers eat the producers, and the secondary consumers eat the primary consumers. Some animals can act as primary and secondary consumers, like humans (we can eat plants and animals). Some animals, bacteria and fungi act as decomposers, breaking down dead organic matter so that the producers can reuse it.
So, what is meant by the abiotic part of the ecosystem? It’s the opposite of the biotic, which means that it’s all the non-living parts of the environment. Abiotic includes sunlight, amount of water, amount of shade and the rockiness of the land. But we can take this one step further: the biotic can affect the abiotic and the abiotic can affect the biotic. Animals can drink and use up water; too much sun can kill plants.
There are thousands of ways that the different parts of an ecosystem interact that are all equally important. For example, if the sun kills all the plants that the animals eat, then the animals will die and will not use up the water. There are a lot of different interactions that happen between abiotic and biotic parts of the environment, but there are also several important interactions that happen among the biotic parts of the environment:
|Type of relationship||Description of relationship||First organism in relationship||Second organism in relationship|
|Parasitism||When one organism benefits from and harms another organism while it’s still alive||Parasite benefits||Host harmed|
|Predation||When one organism feeds off another organism by killing it||Predator benefits||Prey killed|
|Commensalism||When one organism benefits from another organism without harming it or helping it||Commensal benefits||Host unaffected|
|Mutualism||When two organisms help each other||Benefits||Benefits|
|Competition||When two organisms try to get the same resources and end up harming each other||Harmed||Harmed|