Aug 15, 2023
Scientists looking for the most diverse ecosystem on the planet would do well to dig a little deeper. That’s because as many as two-thirds of all species of living things on our planet live in the soil under our feet. That's according to a new study.
Ecologists in Switzerland teamed up for the study. They used dozens of existing studies to compile their findings. Their work was published this month in the journal Proceedings of the National Academy of Sciences. In total, they discovered that 90% of fungi live in the world's dirt. So do 85% of plants and over 50% of bacteria. One family of worms, enchytraeidae, is almost entirely below ground. 97% of the species lives there, in fact. Mammals, at 3%, are the least likely to live underground.
“Here, we show that soil is likely home to 59% of life,” Dr. Mark Anthony wrote in the paper. That makes it "the singular most biodiverse habitat on Earth."
A single teaspoon of soil can contain over 1 billion bacteria. It can also host enough fungus to stretch a full kilometer. That makes it hard to accurately gauge just how much life exists below our feet, experts say. But what is clear is the importance of saving the ecosystem of Earth’s crust, Anthony argues.
"Soils are under enormous pressure," Anthony notes. "Our study shows that the diversity in soils is great and correspondingly important."
Reflect: How might the world beneath our feet, full of bacteria, fungi, and worms, be connected to the health of the entire planet?
Urban Trees
This resource is comprised of of five 45-minute lessons where students will learn about the benefits of trees, predict and analyze the temperature difference of soil in the shade and direct sun, draw a map of all trees on their school grounds, and identify trees using a dichotomous key, tree identification guide, or app.
What Happens If We Cut Down All of a City’s Trees?
This animated video begins by comparing two ancient civilizations and explains why trees are crucial to humans in urban settings.
Why Is Soil One of the Most Amazing Things on Earth?
This video is about the importance of soil to biodiversity and the Earth's food chains.