Ecosystems and Ecosystem Services

Source: Food and Agriculture Organization of the United Nations, 2013, Nadine Azzu, FAO  "The Youth Guide to Biodiversity" 1st Edition (Chapter 5) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 5. Verbatim.

 An ecosystem can be considered the house where biodiversity lives – in terms of the physical location and the interactions that occur within this space. An ecosystem is made up of physical and chemical (abiotic) and living (biotic) factors – for example, rocks, air and water are physical/chemical factors, while plants, animals and microorganisms are living factors.

Pollinators in a garden in France.

© Richard Guerre (age 14)

An ecosystem is a system which contains biodiversity at all levels – including species diversity and genetic diversity – and encompasses the interactions and dependencies of biodiversity.

One wonderful quality of ecosystems is their delicate balance. The abiotic and biotic factors interact with each other in such a way that all components of the ecosystem give and take just enough from each other, and in just the right way, to keep the ecosystem healthy. This “giving and taking” also allows for the ecosystem to provide different types of services (called ecosystem services) to the environment – including to humans.

There are many reasons why different ecosystems are so fascinating – and one of those reasons is that a single ecosystem can contain many small ones. Let’s take the case of a simple garden. In a garden, there can be grasses, flowers, bushes, maybe a tree or two, and if we want to be fancy, even a little pond. Of course, there is also the soil, and animals such as ants, worms and bees. But within that garden, there are what we can think of as microecosystems. 

For example, in the soil there are millions of tiny micro-organisms of all types. These micro-organisms are part of an intricate food chain, both under and above the ground. They also provide ecosystem services that keep the soil healthy, regulate water and capture carbon.

Ecosystems can be classified in various ways. Some ecosystems are natural, whereas others are modified and managed by humans. Ecosystems can be either terrestrial or aquatic. The different combinations of genes, species and microecosystems within an ecosystem are part of what makes each one unique.