The Hidden Life of Trees

Published in the Toronto Star – April 15, 2017

This is a first: a book about trees has been on the ‘best sellers’ list for over 25 weeks.  This may be the first time that a book about trees made it on to this esteemed list at all.  Who, after all, is so interested in trees that they would read a whole book about them?

The book is titled, The Hidden Life of Trees, what they feel, how they communicate, Discoveries from a Secret World.  Now there is a mouthful.  Written in German by scientist, forester and tree lover Peter Wohllenben, it has been translated beautifully into English.  This book provides an eye popping education about the social life of trees and a scientific explanation for their existence and evolution.  Remarkably, it holds the readers interest throughout, in turns captivating you with remarkable details and making you laugh.

Here are the highlights:
1.  Trees talk to one another.  Ok, they don’t talk the same way that we do but they communicate through a symbiotic relationship with soil borne fungi through their roots that, ‘act as intermediaries to guarantee quick dissemination of news.  These fungi operate like fiber -optic Internet cables.’

And what do they communicate?  Weather conditions, insect infestations and human intervention.  Wohllenben calls it the ‘wood wide web’ (see the humour?)

2. Social network. Trees love each other.  At least, they look out for each other.  At the root zone, ‘there is a lively exchange going on down there.  Whoever has an abundance of sugar hands some over; whoever is running short gets help.’  Trees perform best (and are happiest) when they grow together, like in a forest.  Contrary to what we are inclined to think about the ‘survival of fittest’, trees ‘Would shake their heads (at the idea of ‘survival of the fittest’) – or rather their crowns.  Their well-being depends on their community and when the supposedly feeble trees disappear the others lose as well.’
3. Interdependence on wild life. Trees do not exist in isolation of the natural world around them.  They rely on birds to carry their seeds to new jurisdictions, insects to nurture the soil at their roots and in the case of European beeches and oaks, during years of heavy seed set wild boars rely on these trees to fatten them up and multiply while spreading seeds everywhere.  Wohllenben does a masterful job of explaining how wind, sun, rain and even severe weather events, including fire, play important roles in the development of a healthy forest.
4. 4. Street Kids. Wohllenben calls urban trees the ‘street kids’ of the forest.  They live a hard life, without the benefits of a tree community and other wildlife to support them, as in a forest environment.  The greatest limiting factor in the life of a city-tree is soil.  Or the lack of it.  One mystery that he solves for me is the answer to the question, ‘why do trees often produce roots that seek out drainpipes and sewers?’  It  was commonly thought that they were looking for moisture.  Not so, according to the author.  Based on a study by the Ruhr University.  ‘what was attracting tree roots to underground pipes was loose soil that had not been fully compacted after construction.’

In other words, urban trees go out of their way to avoid soil compacted by traffic and construction machines.  When that is not possible, they die prematurely or simply never perform at their optimum.

Urban trees suffer from a variety of maladies brought on by city heat during evening hours in the summer, a lack of access to water due to barriers like concrete sidewalks and paved roads, dogs peeing on them, road salt and pests that favour the urban environment like aphids and scales.

One caveat to being a street kid: often specimens of the same species are planted within proximity to each other which allows them to communicate quite freely.  ‘Whatever these street kids talk to each other about through their scent-mail and whether the tone of these messages is as rough as their lives – the street gangs are keeping this information strictly to themselves.’  More humour.

Some tree facts:

• To produce one pound of wood, a tree needs 22 to 36 gallons of water depending on the species.
• Trees are incredibly effective air filters. One square mile of forest can filter up to 20,000 tons of particulate material from the air per year.
• Green is the dominant colour of the forest for a peculiar reason. It is the one colour that a tree cannot filter out during photosynthesis.  As a result the colour green is reflected back, unused.
• Autumn colours in deciduous tree leaves don’t ‘change colour’, the chlorophyll merely makes an exit and the real colour of the tree leaves is revealed.

And finally, why are trees so misunderstood?  ‘They are so incredibly slow.  Their childhood and youth last ten times as long as ours.’

Interesting: the very reason why we fail trees is the most endearing reason to love them.

 

The Hidden Life of TREES by Peter Wohllenben, Greystone publishing.