
Chromatography of a soil sample, a low-tech method for assessing soil composition and health, including microbial population.
Source: Eugenio Gras / Milkwood
When we think of healthy soil, we usually think of pH levels, mineral content, and availability of water. When we think of biodiversity, we think of animals and plants.
And then there’s soil biodiversity. One tonne of soil can harbor up to 25% of its weight in living microorganisms. And it is this group of life that is responsible for the nutrient exchange of the soil, its carbon and nitrogen content, its structure.
A recently published study published in Science suggests that soil-dwelling microbes may be temperature dependent, and that their composition in a given soil may change with rising temperatures. Microbes that currently enrich soils in temperate regions could find themselves competing against arid-climate microbes.
This could in turn, of course, affect soil health as much as drought or other climate change impact. The question as to just how microbe migration might impact larger environments remains open.

Simplified Soil Food Web, showing bacteria and microorganisms at the 2nd trophic level.
Source: European Soil Portal
More:
Science study – Temperature Drives the Continental-Scale Distribution of Key Microbes in Topsoil Communities by F. Garcia-Pichel, V. Loza, Y. Marusenko, P. Mateo, R.M. Potrafka
Scientific American post/podcast – Climate Change Alters Soil Bacteria Distribution