"Soil is not an inert substance, but a vast repertoire of hidden life. Billions of microorganisms are present in just a gram of dirt, while one hectare can hold up to five tonnes of animal life. Some, like toads, snakes and ants, are visible to the naked eye, but the vast majority of -microbes, fungi, bacteria- are invisible."
"This dark domain harbors a quarter of all known biodiversity on earth, and a staggering 80% of its biomass. Yet for all its abundance and proximity, the ground beneath our feet is more unknown than the depths of the ocean floor and the heights of the tropical canopy. Only 10% of the 2 million species of bacteria and fungi have been catalogued to date."
Carolyn Lebel, "Living Soil," Resurgence and Ecologist, Sept/Oct 2012. https://www.exacteditions.com/read/resurgence/september-2012-32475/4/3