Underground biodiversity (also called soil or belowground biodiversity) is made up of the living organisms that exist belowground. This includes bacteria, fungi, nematodes, and larger fauna like earthworms and insects. An essential component of the global ecosystem, underground biodiversity makes up more than half of life on Earth.

Astoundingly, soils are estimated to be home to 59% of all Earth’s life including everything from microbes to mammals, making it the singular most biodiverse habitat on Earth.

This biodiversity provides multiple ecosystem functions and services, including climate regulation, soil formation and decomposition.

Soil biodiversity is currently under-represented on the IUCN Red List. This is most likely a reflection of the relatively small proportion of species assessed to date: only 0.18% (12,484 species) of the world’s estimated 7 million terrestrial arthropods, and only 0.04% (794 species) of the estimated 2 million fungi species have had their global conservation status assessed.

Protecting biodiversity is critical for maintaining ecosystem health and resilience in the face of global change. Despite being the most diverse community on land and key drivers of almost all ecosystem processes, soil organisms are rarely considered in conservation planning.

Take-home: Because the vast majority of soil-dwelling species remain hidden, identifying extinction risks and mapping underground populations is one of the biggest challenges in global conservation. For this reason SPUN focuses on mapping, protecting, and restoring this hidden biological network.

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