Since 2015 has been declared the International Year of Soils by the 68th UN General Assembly let’s see some facts about soil and underline how important soil biodiversity is.
Fact No 1: Soils are home to over a quarter of all living species on earth.
This diverse ecosystem performs a variety of functions. It processes waste organic matter to sustain life above the ground, from plants to animals to humans; it regulates the carbon fl ux and the water cycle; it keeps pests at bay and decontaminates polluted land; and it provides raw materials for new pharmaceuticals to tackle infectious diseases.
Fact No 2: Only 1% of soil micro-organism species have been identified.
Soil is the factory of life and its workers are micro-organisms, small and large invertebrates, small mammals, even plant roots – their workplace is the dark or dim layers of topsoil beneath grasslands, fields, forests and green spaces in towns. Unfortunatelly, the factory is in crisis.
Fact No 3: In an area the size of a football field, soil organisms produce organic matter equivalent to the weight of 25 cars every year.
The main business of the factory of life is to create and refresh soil, the most essential food source on the planet. It provides the nutrients that plants need to grow and sustain animals, including by producing our own food, textile fibres, wood and ingredients for pharmaceuticals.
Fact No 4: Soils without earthworms can be 90% less effective at soaking up water.
A similarly vital role of the below-ground factory of life is to purify and store water. As water infi ltrates the ground, contaminants including bacteria and viruses are absorbed by soil particles, making the water both clean and safe. However, this purifi cation capacity depends on the soil being rich in micro-organisms, which perform the work. The more biodiversity in soil, the better this function can be performed.
Fact No 5: Land without vegetation can be eroded more than 100 times faster than land covered by vegetation.
Meanwhile, channels, nests and galleries created by earthworms, ants and termites all promote water absorption, while vegetation, with its leaf litter and root systems, helps to capture water and to structure the below-ground soil. Cutting back vegetation, for example by deforestation, does the opposite, allowing soil to be washed away. Without a vibrant soil community, the soil becomes poor in structure and water run-off increases, leading to erosion and flooding.
Fact No 6: Earthworms can enhance bioremediation, as they regulate the activity and distribution of microbes in the soil.
Bioremediation is a natural process which has been frequently harnessed by humans. It is the cheapest method of soil decontamination and has proved effective in numerous cases.
Fact No 7: Each year, across the world, 75 billion tonnes of soil are stripped from the land by wind and water erosion, most of it from agricultural fields. This environmental damage can result in human disaster, as people are forced to leave their homes in search of fertile cropland.
Erosion strips the roof off the soil factory, damaging the complex organisation beneath. It occurs when the surface is scraped off the soil by wind and water, and affects many European soils, the result of farming practices, deforestation, overgrazing, forest fires and construction work. It is expected to worsen with climate change.
So, what do you think?Is soil biodiversity important or not?