The seemingly inert ground beneath us teems with a vibrant, often overlooked, ecosystem. Soil scientist Frank Ashwood, in his exploration of the underground world, highlights that soil is alive with activity, producing a symphony of sounds as plants and invertebrates move through it.
These subterranean noises, recorded by scientists, range from a low rumbling caused by plant roots pushing through the earth to the sand-like sounds of raking, creaking similar to a settling house, and a series of clicks. This 'underground orchestra' comprises ants, beetles, springtails, fly larvae, centipedes, woodlice, and spiders navigating their dark environment. The intensity of this activity serves as an indicator of soil health, with more bustle signifying a healthier ecosystem.
Ashwood expresses a deep affection for springtails, small insects vital for soil's recycling processes. These creatures are notable for their remarkable jumping ability, capable of propelling themselves up to 100 times their body length, an equivalent to a human jumping over a 45-story building.
Dead and decaying wood plays a crucial role in maintaining soil and forest health. Historically, fallen wood was often removed, but current understanding recognizes its importance. Dead wood supports up to 40 percent of all forest organisms, and many gardeners now intentionally create damp log piles.
The soil ecosystem is home to a diverse array of creatures. Among them is a mite species that has reproduced exclusively without males for 100 million years through parthenogenesis, or virgin birth. The notes also mention the aggressive Asian jumping worm and trigonotarbids, extinct ancestors of spiders. The velvet worm, equipped with 'glue-firing cannons' on its head, and the giant Badischer Riesenregenwurm, an earthworm found in Germany reaching up to two feet in length, are also highlighted.
Grasslands, particularly ancient, unsprayed, and moderately grazed ones, can harbor astonishing amounts of underground biomass. An ancient grassland could contain as much as 100 tonnes of living biomass per hectare, an amount Ashwood likens to the weight of approximately 15 African bull elephants living beneath a standard rugby pitch.
While global forest cover has decreased significantly from its historical peak, Ashwood suggests that planting trees isn't always the sole solution. He advocates for agroforestry, also known as wood pasture, which involves interspersing grasslands or crops with trees and thickets. This traditional farming landscape, common in parts of Britain and Europe, is something Ashwood hopes will continue to thrive.
With at least a third of the planet's soils experiencing moderate to severe degradation, Ashwood underscores the urgent need to value soil resources. He links the health of our soil directly to the well-being of nature, wildlife, and the future of humanity.