Forest soils are teeming with life and biodiversity. They enable the growth of trees, berry plants and mushrooms that are essential to human consumption and economy and contribute to mitigation of the climate change by storing carbon and consuming greenhouse gas methane.
Fruits of our forests
Forests are important providers of tangible goods like berries, mushrooms, and game animals, as well as wood, which is used as raw material for processing and manufacturing. In addition, forests provide many invaluable intangible goods.
They can be used for various recreational activities, and provide an endless source of aesthetic beauty, tranquility, and artistic inspiration. They also play a major role in global environmental protection, holding a major part of world’s biodiversity, preventing soil erosion, and flooding, and mitigating climate change by sequestering carbon from the atmosphere.
The bounty beneath our feet
Yet there would be no forest without the soil beneath the trees and other plants. Much more than just the ground on which we walk, forest soils are teeming with life and biodiversity, from plant roots, worms, and insects to microorganisms like protists, fungi, bacteria and archaea.
Hard at work
These organisms are responsible for the degradation and decomposition of organic matter, such as fallen leaves, pine and spruce needles, and dead tree branches. They transform part of this organic matter into carbon dioxide, which is a climate warming greenhouse gas, but which the trees and plants can use again for their growth in photosynthesis.
When organic matter decomposition takes place deep in the soil, in oxygen-free conditions, methane, another greenhouse gas, can also be formed. Luckily, the soil contains microorganisms which eat this methane very efficiently. In fact, such methane-eaters can be so effective that many forest soils do not emit methane to the atmosphere but mitigate climate change by sucking the greenhouse gas out from the air.
The organisms responsible for decomposing the forest’s organic matter release essential elements and nutrients, like nitrogen and phosphorous, and recycle them into forms which trees and other plants can take in via their roots and use for their growth.
Some forest soil microorganisms can even suck nitrogen gas from the atmosphere and convert it into forms that trees and plants can use. When the microorganisms release and recycle nitrogen, a third important greenhouse gas, nitrous oxide, can be formed. However, as for methane, there are other microorganisms which consume it. Depending on conditions and soil type, forest soils can either emit nitrous oxide or suck it out from the air.