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I received a most thoughtful Christmas gift from my son Ian, a book I had been looking forward to reading: “The Hidden Life of Trees, What They Feel, How They Communicate, Discoveries from a Secret World” (Peter Wohlleben, Random House 2015).

Late in the book, Wohlleben makes a point at the heart of the challenges faced by arborists and foresters: “many people today see trees as noting more than objects ... We misunderstand them (because) they are so incredibly slow. Their childhood and youth last 10 times as long as ours. Their complete life span is at least five times as long as ours. Active movements such as unfurling leaves or growing new shoots take weeks or even months. And so it seems to us that they are static beings, only slightly more active than rocks.”

A few pages later he refers to trees as “vegetative beings.” Through personal observations and citations from intriguing scientific work he makes a strong case for trees as “beings.”

In the course of his career in northwestern Germany “in the forest I manage,” as he often says in the book, Wohlleben began to organize survival trainings and log cabin tours, and he designated a section of the forest where people can be buried as an alternative to traditional graveyards. Visitors made observations and asked questions that changed his perspective. He made a transition from working with trees as a commodity to seeing them as dynamic, complex living things.

Working to bridge the perception gap — trees as static things versus trees as dynamic life forms — Wohlleben often compares processes and anatomy in trees to those in people.

Where he explains that trees can respond to the saliva of a particular leaf-eating insect pest by generating specific protective chemicals, he calls it evidence trees “must have a sense of taste.”

Where he explains that a bird cherry tree rejects pollination by its own pollen, a function that serves to avoid “inbreeding,” he says it is as if the tree can “feel” the pollen.

In his discussion of beech trees breaking dormancy, he purports that trees must have a sense of time, an ability to see, a sense of temperature, and some kind of memory.

In fact, as he states, beech trees break dormancy when day length increases to 13 hours per day in spring. And whatever ability to “see” they posses is aided by their dormant bud scales being transparent.

Chapters include “Social Security,” where trees in a forest are shown to equalize differences among strong and weak trees. “Love,” where beech and oak forests are shown to engage in strategic reproduction. Entire forests will hold off on reproduction, serving to starve out some of the seed eating herbivores and insects, then produce seed en masse all in one year, providing an over abundance of beech nuts or acorns. As a result, there is too much food, which gives some of the extra seeds an opportunity to germinate and escape being eaten.

Food for thought!

Topics he explores include:

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— “Carbon Dioxide Vacuums”: “Some of the CO2 fixed in the trees returns to the air when the tree dies but most of it remains locked in the ecosystem forever.” Large old trees, contrary to common belief, grow faster, e.g. generate more wood than young trees. “If we want to use forests as a weapon in the fight against climate change, then we must allow them to grow old.”

— “Woody Climate Control”: Trees can create and sustain the very environment they need.

— “Forest Water Pump”: Coastal forests absorb rainwater coming off the oceans then evaporate and relay it inland. He quotes studies that have shown that “it is always trees that transfer moisture into land-locked interiors and the process breaks down if coastal forests are cleared.”

— “United We Stand”: Fungi work intimately with tree roots for mutual survival in the “wood wide web.”

He puts forth and strongly supports the idea that forest ecosystems achieve a “fullness of life with tens of thousands of species interwoven and interdependent.”

Wohlleben also discusses health benefits bestowed by forest air, resulting from particulate filtering and the emission of “phytoncides” from trees. He says, “Personally, I think the swirling cocktail of tree talk is the reason we enjoy being out in the forest so much.”

I will take a deep breath and drink to that.

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Bill Pramuk is a registered consulting arborist. Visit his website,, email questions to, or call him at 707-226-2884.