Distance is not a barrier

It might seem as if plants are solitary and isolated individuals, but because of their special relationship with fungi, they can communicate with each other over great distances. The mycorrhizal relationships between plants and soil fungi are well known. These fungi form a network of branches called mycelium that extend through the soil, including around or inside the roots of plants. These branches enable the fungi to absorb soil nutrients, such as nitrogen and phosphorus and transfer them to the plant.

Read more about this special plant-fungi relationship here: Mycorrhizal fungi: The plant’s secondary root system

In addition to fungi, plants share nutrients with each other prioritising plants where the nutrients are needed the most. We know that through the process of photosynthesis plants can capture carbon and turn it into sugar and oxygen. Plants that are in the shade will have less sugar, so through fungi, the plants in the light will transfer excess carbon to plants that cannot access it. Basically, this is the plant fungi equivalent of feeding the hungry.

The interacting networks where plant to plant exchange occurs, via fungi, are called common mycelium networks (CMN). Any plants or fungi that are plugged into the CMN, have a higher likelihood of surviving attacks from pests and the plants that are connected are generally healthier too. When a plant is attacked by pests or pathogens, the CMN transfers the distress signals released by the attacked plant to other plants signalling that something bad is coming their way.

This early warning system enables plants to become healthier because they can prepare for the imminent attack in time. If the pathogen originates from the soil, the further fungi are also able to send chemical re-enforcements to areas where the CMN network is vulnerable and thus help to fight off the problem organism and maintain the connections.

Take away

The CMN increases security, awareness, and knowledge for those connected to it.  Any soil management action that results in the breakage of these connections, such as tillage and fungicides, destroys the entire nerve system of the soil thus isolating plants and soil organisms from each other. The result of this cut communication creates soil systems and plants that are vulnerable to attacks which will lead to chemical usage dependency such as pesticides.

Sources

Underground Networking: The Amazing Connections Beneath Your Feet

Common Mycelial Networks: Life-lines And Radical Addictions

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