Royal Forestry Society: Mycorrhizas: What is happening below forest floors?

On the eve of his forthcoming appearance at The Tree Conference  in Frome, Somerset, next month, Dr Martin Bidartondo assesses the fate of trees and fungi in our changing world

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Lactarius quietus (oak milkcap) fungus-root.  Pic Credit: Dr LM Suz.

 

Most plants do not have roots, they have fungus-roots, also known as mycorrhizas.  Above the ground, plants have mastered the art of making carbohydrates through photosynthesis, but below the ground plants have contracted out the difficult job of mining for scarce soil minerals like nitrogen to fungi.  Soil minerals are essential for making all components of plants and fungi.  Fungal filaments are finer and longer than roots, so fungi can explore soil more thoroughly, can grow in and out of roots linking them to the soil, and are able to produce a wider range of enzymes for breaking down complex soil structures.  You could think of these fungi as a soil toolkit for plants.  This is not altruism, these fungi need carbohydrates from plants to be able to make their own component parts and to fuel their soil mining.  Thus, intimate and ancient fungus-root partnerships evolved complementing the nutritional needs of most plants and some fungi.  In fact, we are now learning that this partnership has long controlled the carbon and nitrogen cycles on land.  However, since the Industrial Revolution, humans have been increasingly interfering with carbon and nitrogen cycling.  Recently, alarming nutritional imbalances have been reported across Europe’s forest trees.  What is happening with fungus-roots in our forests?  It has taken ten years of research, but we now have some clues.

To read the full article visit :

http://www.rfs.org.uk/news/blog-spot/mycorrhizas-what-is-happening-below-forest-floors/