Study questions 3 widely accepted beliefs about CMNs

At a glance

• Scientists have questioned three widely accepted beliefs about the capabilities of common mycorrhizal networks (CMNs)
• A review of 26 studies found that resources can be transferred underground by trees, however, there is no evidence to suggest that CMNs are responsible for this flow
• No evidence from any peer-reviewed, published field studies to support the claim that adult trees preferentially send resources or “warning signals” of insect damage to young trees through CMNs
• The commonly held beliefs about CMNs may be exaggerated and could be influencing the way forests are managed
• Further research is needed to gain a better understanding of the abilities of CMNs and their interactions with forests

The details

Scientists Question Three Widely Accepted Beliefs About Common Mycorrhizal Networks

Scientists in the journal Nature Ecology & Evolution have questioned three widely accepted beliefs about the capabilities of common mycorrhizal networks (CMNs), which are underground fungi that connect the roots of multiple plants.

The concept of CMNs has been referred to as the “wood-wide web” and has been widely discussed in the media, however the scientific evidence to support these ideas is yet to be established.

Justine Karst and two colleagues from the University of Alberta have published a peer-reviewed article in the journal Nature Ecology & Evolution which examines three popular claims about the capabilities of CMNs.

Claims Examined

These claims are that CMNs are widespread in forests, resources such as nutrients are transferred by adult trees to seedlings through CMNs and that they boost survival and growth, and adult trees preferentially send resources or “warning signals” of insect damage to young trees through CMNs.

Results of the Study

A review of 26 studies found that resources can be transferred underground by trees, however, there is no evidence to suggest that CMNs are responsible for this flow, and seedlings typically do not benefit from CMN access.

Additionally, there is no evidence from any peer-reviewed, published field studies to support the claim that adult trees preferentially send resources or “warning signals” of insect damage to young trees through CMNs.

The results of the study indicate that the commonly held beliefs about CMNs may be exaggerated and could be influencing the way forests are managed.

Recommendations

The authors of the study recommend that further research is conducted to gain a better understanding of the abilities of CMNs and their interactions with forests.

The study emphasizes the need for accurate information when exploring the intricacies of forests and the role of CMNs.

It is important that the public narrative is based on scientific evidence and not on conjecture or exaggerated assertions.