Life Under The Ground

Microbes living in the soil






Organisms live on top of the soil


Organisms life on top of the soil




Or just underneath the surface






A compost bin is a good soil habitat


Compost bin




Insect exoskeletons


Insect exoskeletons

New Zealand is home to some delightfully different animals. Most of us are familiar with the flightless kiwi, the giant weta and the ancient tuatara.

New Zealand has other less well known, but equally unusual animals like glow-in-dark earthworms and the ‘invertabrate living fossil’ – the peripatus. Perhaps if you’ve not heard of these two, it’s because they live underground or in leaf litter on the surface so we don’t often see them. Look a little closer and you’ll be surprised at the world living beneath your feet.


Soil – Alive Or Dead?

Soil is made up of mineral particles, decaying organic matter, air and water. It also has a fifth component, living organisms. So soil is full of life. Digging over a spade of soil may reveal earthworms, insects and other visible creatures, but there is far more that we cannot see. Scientists estimate that there are more living things in one teaspoon of soil than there are people living on the Earth!


Soil Is A Habitat

A habitat is a specific area in which an organism lives. Around 25% of everything alive on Earth uses soil as a habitat – in which the soil provides food and shelter. Organisms live both on top of the soil (in leaf litter or other organic matter) or below the surface. Some things live in soil for their entire lives while other creatures live in soil for just a part of it.

A soil habitat can be a pretty complicated place. The characteristics of soil (for example, its texture and chemisty), temperature and rainfall influence the type of plants and animals that live in the soil. These living things depend on each other and on the non-living components like organic matter, minerals, air and water to survive.


New Zealand Native Soil Habitats

New Zealand native forests tend to be humid places that do not experience big temperature extremes. The forests may lack the animal diversity of other rainforests around the world, but there is a lot going on under the ground. Believe it or not, the weight of earthworms under our native forests is greater than all of the other animals living in the forest!

Earthworms aren’t the only creatures on the forest floor – the leaf litter may hold hundreds of species of invertebrates. Earthworms, invertebrates and microscopic organisms break down the fallen leaves and wood to recycle nutrients and favourably influence soil properties.

Other native areas, like tussock grasslands, alpine shrub lands and costal areas will have their own soil ecosystems. Anywhere there is soil; there will be a soil habitat.


Urban And Other Habitats

The lawns and gardens around our houses, schools and businesses are home to all kinds of soil life, but we have to look to see it. Dig a hole, spread the soil out on a piece of newspaper and take some time to see what you can find.

You can even create a soil habitat where none existed by building a compost system. Add a spadeful of soil or two to an empty bin and add food scraps or grass clippings on a regular basis. It won’t take long before the compost bin is home to insects, earthworms and microscopic creatures.


Life Above The Ground Depends On Life Below The Ground

It’s just as well that soil organisms break down and recycle plant and animal wastes. Consider just one type of waste – insect exoskeletons. If these were never recycled, we’d be knee deep in insect body parts. Now think about all the leaves that fall, cow dung deposited, potatoes that get peeled and teabags we use. Life above ground wouldn’t exist without the help of life below the ground!


Activity Ideas

The activities Soil Microbes and Soil Animals are simple, visual, hands-on experiences to explore life under the ground.


Digging Deeper

Learn more about what live in soil by visiting the Science Learning Hub’s earthworms, Te Ara’s Earthworms and Massey University’s Soilbugs.