Network of Microbes Connecting Trees Globally Has Been Mapped for the First Time

For the first time, the millions of species of fungi and bacteria that form an interconnected web of organisms throughout the world’s forests, exchanging nutrients between the soil and the trees, have been mapped. The findings were published in the journal Nature, titled “Climatic controls of decomposition drive the global biogeography of forest-tree symbioses.”

The locations of microbes were mapped using a database of almost 30,000 species of trees in more than 70 countries.

The microbes that were mapped in the database:

  • The ectomycorrhizal (EM) fungi surrounding oak and pine, that build vast underground networks in their search for nutrients.
  • The arbuscular mycorrhizae (AM), which burrow directly into trees’ root cells but form smaller soil webs and are connected to maple and cedar trees.
  • And other microbes that surround trees, primarily of the legume family, that turn nitrogen in the atmosphere into usable plant food, known as fixing nitrogen.

Researchers put together a computer algorithm to find EM, AM, and nitrogen fixing microbes correlated with associated trees and the local environment, like temperature, precipitation, soil chemistry, and topography.

Researchers then used the patterns they discovered to fill in a global microbe map and predict what kinds of fungi and bacteria would live where they didn’t already have data, including much of Africa and Asia. The findings from the algorithm were supported by local sampling.

The findings could help build computer models to better predict how much carbon forests can hold and how to effectively reforest the planet.



Photo: “Forest Canopy” by wackybadger is licensed under CC BY-SA 2.0