ABSTRACT
Soil contains a very diverse ecosystem of viruses, archaea, bacteria, unicellular eukaryotes, invertebrates, and vertebrates interacting and making the soil better for life. Soil’s properties that benefit life are created by life. These include friability, porosity, and availability of nutrients, such as nitrogen. Soil is made partly by volcanism, but mostly by life. Lichens, plant roots, and fungi break down rocks. Bacteria and fungi break down organic matter, release essential nutrients and make them available to life, recycle nutrients, keep nutrients from being washed away, bind soil particles together, provide other services to soil, and are essential to soil health. Some soil bacteria fix nitrogen. Larger animals, such as rodents and tortoises, dig tunnels that aerate the soil and are habitat for commensal species that benefit from this, such as lizards. Plants, especially trees, break down rock, help make soil, increase its porosity, prevent soil erosion with their roots and with the help of their symbiotic root fungi, protect soil from rain and sun, and provide nutrient to all of the soil organisms.
