Crown Shyness – An Amazing Phenomenon Waiting To Be Understood

When you take a stroll next time in the woods, remember to look upwards and you might see streams of sunlight seeping in through the cracks of fissures between fine definitions of tree canopies.

This picturesque known as “Crown Shyness” is when the summit of tree canopies refuses to be in contact with their neighbours.

The behaviour displayed between trees can be found globally but mainly in few species such as Eucalyptus, Stika Spruce and Japanese Larch.  Crown Shyness can occur amidst same or different species with the similar outlook nevertheless.

Although baffled scientists have no concrete explanation for this since 1920, there are substantial theories conjured in an attempt to demystify the phenomenon.

To Avoid Branches Gashing At Each Other

Especially so with windy howls, branches will conflict each other with subsequent injury. The trauma would then result to Crown Shyness’s frequent gaps.

This theory is backed up by prominent figures in the field such as Australian forester M.R. Jacobs in his 1955 book “Growth Habits of Eucalypts” and Dr. Miguel Franco’s paper published in “Philosophical Transactions of The Royal Society” in 1986 where both described the gaps would subsided the abrasion of the branches’ tender ends.

However the scientific community has denied the notion such as Malaysian scholar Francis S.P. Ng in 1977 ascertained no proof of injury through rough abrasion.

To Fend Off Harmful Insects

Colonies of ants are able to build bridges with their bodies linking through each other. The teamwork close breaches and creates shortcuts while journeying through challenging routes.

They are able to extend a bridge up to four inches (10 centimetres) and longer, hence the gap is an inbuilt defence mechanism to prevent leaf eating insects from climbing over.

A Unified Response To Acquire Optimum Light Sources

This evolution theory proposes foliage of neighbouring trees synchronized to grow away from each other to prevent competition for optimum light sources.

Plants’ phytochrome photoreceptors used a certain light frequency so they are able to be aware of their neighbours’ presence.

By detecting the far red end of the light spectrum, plants can distinguish and adjust the space between their canopy neighbours. Whereas detecting blue light at the other spectrum end to prevent growing into the shadows.

The functions allow plants to detect and adjust their foliage growth away for best spot of light source.


Regardless which theory prevails from harmful insects to positioning for the best lighting spot; Crown Shyness surely represent how profound Mother Nature can be.

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