Study of a Tree

Georges Michel (French, 1763-1843)Georges Michel (1763-1843)


by Hope Jahren

A seed is alive while it waits. Every acorn on the ground is just as alive as the three-hundred-year-old oak tree that towers over it. Neither the seed nor the old oak is growing; they are both just waiting.
What each seed is waiting for is known only to that seed. Some unique trigger-combination of temperature-moisture-light and many other things is required to convince the seed to jump off the deep end and take its chance–to take its one and only chance to grow.
. . . .
When you go into a forest … you probably don’t look down, where just beneath your single footprint sit hundreds of seeds, each one alive and waiting. They hope against hope for an opportunity that will probably never come. More than half of these seeds will die before they feel the trigger that they are waiting for, and during awful years every single one of them will die.
. . . When you are in the forest, for every tree that you see, there are at least a hundred more trees waiting in the soil, alive and fervently wishing to be.

A coconut is a seed as big as your head. It can float from the coast of Africa across the entire Atlantic Ocean and then take root and grow on a Caribbean island. In contrast, orchid seeds are tiny: one million of them put together add up to the weight of a paper clip. Big or small, most of every seed is actually just food to sustain a waiting embryo. The embryo is a collection of only a few hundred cells, but it is a working blueprint for a real plant with a shoot and a root already formed.
When the embryo within a seed starts to grow, it basically just stretches out of its doubled-over waiting posture, elongating into official ownership of the form that it assumed years ago.
. . . .
After scientists broke open the coat of a lotus seed and coddled the embryo into growth, they kept the empty husk. When they radiocarbon-dated this discarded outer shell, they discovered that their seedling had been waiting for them within a peat bog in China for no less than two thousand years. This tiny seed had stubbornly kept up hope of its own future while entire human civilizations rose and fell.

With gratitude to Nicolas Silver for presenting me with the book from which this incomplete excerpt is lifted.
“Lab Girl” is a 2016 memoir by American geochemist, geobiologist, and professor Hope Jahren.



A Midsummer Night

midsummer night dream lDetail, Scene from A Midsummer Night’s Dream
Edwin Landseer (1802 – 1873)


Everything changes, nothing dies: the spirit wanders, arriving here or there, and occupying whatever body it pleases, passing from a wild beast into a human being, from our body into a beast, but is never destroyed.
So, I say as a seer, cease to make kindred spirits homeless, by wicked slaughter: do not let blood be nourished by blood!

Pythagoras of Samos (c. 570 BC – c. 495 BC)

in Ovid’s Metamorphosis


It Could Take a Century to Recover

elephant5Portrait of an Elephant, Indian, c.1620-30

Study finds extremely slow reproduction rate unable to keep pace with deaths

African forest elephants have experienced serious poaching, driving an estimated population decline of 65% between 2002 and 2013.
Their low birth rates mean that it will take forest elephants at least 90 years to recover from these losses, according to researchers from the Wildlife Conservation Society, the Cornell Lab of Ornithology’s Elephant Listening Project, Colorado State University, and Save the Elephants.

These findings are from the first-ever study of forest elephant demography just published in the Journal of Applied Ecology.

“Female forest elephants in the Dzanga population typically breed for the first time after 23 years of age, a markedly late age of maturity relative to other mammals. In contrast, savannah elephants typically begin breeding at age 12.
In addition, breeding female forest elephants only produced a calf once every five to six years, relative to the three to four-year interval found for savannah elephants.”
Andrea Turkalo, a Wildlife Conservation Society scientist, collected the detailed data on the elephants over several decades, in spite of tough logistical challenges and political instability.
“This work provides another critical piece of understanding regarding the dire conservation status of forest elephants.”

George Wittemyer, a professor in Wildlife Conservation at Colorado State University said, “Legislation regarding ivory trade must consider the collateral effects on forest elephants and the difficulties of protecting them. Trade in ivory in one nation can influence the pressures on elephants in other nations.”
And the forest elephant is particularly susceptible to poaching.

Forest elephants also have critical ecological roles in Central African forests, and many tree species rely on the elephants to disperse their seeds.
Those forests are vitally important for absorbing climate change gases.

Surrendering Forests

tree david johnsonDavid Johnson (1827 – 1908)

by Jeff Tietz
Rolling Stone

From a tree’s perspective, excessive heat may be as deadly as lack of water.
To photosynthesize, a tree opens pores in its leaves called stomata and inhales CO2. Solar-charged chemical reactions then transform the CO2 into carbohydrates — the raw stuff of leaves and wood. During this process, a fraction of the tree’s internal water supply evaporates through its stomata, creating the negative pressure that pulls water from the soil into the tree’s roots, through its trunk and up to its canopy. But heat juices the rate at which trees lose moisture, and that rate escalates exponentially with temperature — so small temperature increases can cause a photosynthesizing tree to lose dangerous amounts of water.
“Forests notice even a one-degree increase in temperature,” says Park Williams at Los Alamos National Laboratory.

In the death scenario, the sky sucks water from the leaves faster than it can be replaced by water in the soil, and the resulting partial vacuum fatally fractures the tree’s water column. If a tree closes its stomata to avoid this, shutting down photosynthesis, it risks starvation.
Ultimately, the tree’s cellular chemistry will fail, but it will often die before that, as its defenses fall; the complexly toxic sap that repels predatory insects dries up.
Many insects can detect diminished sap levels within tree bark by scent — they smell drought stress and pheromonally broadcast news of deteriorating tree health. Other defenses – against microbes, for example — may also be compromised.
A hotter climate generally means more insects.
It also means more, and more intense, wildfires.

For decades, all over the planet, heat-aggravated drought has been killing trees: mountain acacia in Zimbabwe, Mediterranean pine in Greece, Atlas cedar in Morocco, eucalyptus and corymbia in Australia, fir in Turkey and South Korea.
In 2010 a group of ecologists published the first global overview of forest health. They described droughts whose severity was unequaled in the “last few centuries” and documented “climate-driven episodes of regional-scale forest die-off.”

Because global warming outpaces evolutionary adaptation, the question is: Can trees survive as they are?
The conifer forests of the Southwest United States, if climate projections are even minimally accurate, cannot, but what about the rest of the world’s forests?
That’s a critical question, because forests cover more than a quarter of the planet’s land, and they help stabilize the climate by pulling immense quantities of CO2 out of the air.
In August 2011, a team of scientists led by Dr. Yude Pan, a U.S. Forest Service researcher, reported that between 1990 and 2007, forests sequestered about 25 percent of all greenhouse-gas emissions — everything not in the air or seas.

Climatologists worry that if forests across the planet deteriorate, they could, on balance, begin releasing as much carbon as they absorb.
One of Pan’s collaborators, Dr. Richard Birdsey: “If the carbon sink in forests fails, a simple speculation is that global temperatures would increase proportionally to the increase of CO2 concentration, so about 25 percent above current climate projections.”
“The more forests die, the less carbon they take out of the air, the warmer it gets, the more forests die,”
says Dr. Nate McDowell at Los Alamos. “It’s a thermostat gone bad.”

The better we understand climate change, the more we seem to find that warming begets warming in unexpected and self-amplifying ways: Implacable heat engines materialize and run independently of all human effort.

There are an estimated 1 trillion metric tons of frozen carbon in the soils of the Arctic region — a century’s worth of global emissions, twice the amount stored in the global forest, another few Industrial Revolutions.
As the planet warms, permafrost thaws and decomposes, sending carbon into the air and further warming the planet. Higher temperatures also kindle increasingly intense and frequent wildfires in high-latitude forests, to quadruple effect.
And fire releases carbon directly; it burns off the insulating upper layer of vegetation, exposing more permafrost to warm air; it blackens the trees and land, which consequently absorb more solar radiation; and its soot can settle on and darken snow and ice sheets to the north, which then also absorb more solar radiation.

By the end of the century, the woodlands of the Southwest will likely be reduced to weeds and shrubs. And scientists worry that the rest of the planet may see similar effects.


Trees Cry Out

The Longevity of Trees
A Living Miracle
Du Bon Usage des Arbres

The Last Word

What good is wallabyLagostrophus fasciatus (Banded Hare Wallaby), 
Charles Alexandre Lesueur (1 January 1778 – 12 December 1846), naturalist, artist, and 
writer on zoological, geological, historical, and archeological research


The last word in ignorance is the man who says of an animal or plant: ‘What good is it?’

Aldo Leopold (January 11, 1887 – April 21, 1948)
Scientist, ecologist, forester, conservationist, and environmentalist



Beatrix Whistler blackberriesBlackberries,
Beatrix Whistler (1857–1896)

We shake down acorns and pinenuts.  We don’t chop down the trees.
– Wintu Indian

Different Kinds of Air

A man, like  mouse, should have more than one avenue of escapeA man, like a mouse, should have more than one avenue of escape
Joris Hoefnagel (1542 – 1604)

                    Observations on Different Kinds of Air
. . . . I flatter myself that I have accidentally hit upon a method of restoring air which has been injured by the burning of candles, and that I have discovered at least one of the restoratives which nature employs for this purpose. It is vegetation. In what manner this process in nature operates, to produce so remarkable an effect, I do not pretend to have discovered; but a number of facts declare in favour of this hypothesis…
One might have imagined that, since common air is necessary to vegetable, as well as to animal life, both plants and animal had affected it in the same manner, and I own that I had that expectation, when I first put a sprig of mint into a glass-jar, standing inverted in a vessel of water; but when it had continued growing there for some months, I found that the air would neither extinguish a candle, nor was it at all inconvenient to a mouse, which I put into it.
…Accordingly, on the 17th of August 1771, I put a sprig of mint into a quantity of air, in which a wax candle had burned out, and found that, on the 27th of the same month, another candle burned perfectly well in it. This experiment I repeated, without least variation in the event, not less than eight or ten times in the remainder of the summer.
Joseph Priestley (24 March 1733 – 6 February 1804)

In 1771, about the time of the first stirrings of the industrial revolution and its appetite for fossil fuel, an English minister grasped key processes of the natural carbon cycle. In a series of ingenious experiments, Joseph Priestley found that flames and animals’ breath “injure” the air in a sealed jar, making it unwholesome to breathe. But a green sprig of mint, he found, could restore its goodness. Priestley could not name the gases responsible, but we know now that the fire and respiration used up oxygen and gave off carbon dioxide. The mint reversed both processes. Photosynthesis took up the carbon dioxide, converted it into plant tissue, and gave off oxygen as a by-product.

The world is just a bigger jar. Tens of billions of tons of carbon a year pass between land and the atmosphere: given off by living things as they breathe and decay and taken up by green plants, which produce oxygen. A similar traffic in carbon, between marine plants and animals, takes place within the waters of the ocean. And nearly a hundred billion tons of carbon diffuse back and forth between ocean and atmosphere.

In other words:
Alone in a sealed jar, a mouse would die from exhaled CO2. But as Priestley observed in 1771, adding a plant allows the mouse to thrive. In this proof of photosynthesis, the mint absorbed CO2, retained carbon for growth, and released oxygen



Pisanello (c. 1395 – probably 1455)Veritas sequitur …

In the small beauty of the forest
The wild deer bedding down—
That they are there!
                              Their eyes
Effortless, the soft lips
Nuzzle and the alien small teeth
Tear at the grass
                              The roots of it
Dangle from their mouths
Scattering earth in the strange woods.
They who are there.
                              Their paths
Nibbled thru the fields, the leaves that shade them
Hang in the distances
Of sun
                              The small nouns
Crying faith
In this in which the wild deer
Startle, and stare out.

George Oppen

Forest Die-Off Detail

Lucas Cranach the Elder (Lucas Cranach der Ältere, c. 1472 – 16 October 1553), Lucas Cranach the Elder (c. 1472 – 16 October 1553)

Trees Cry Out

Carl Blechen (July 29, 1798 – July 23, 1840), Young Oak
Carl Eduard Ferdinand Blechen (1798 – 1840)


When drought hits, trees suffer—a process that makes sounds.
Scientists have known for decades that microphones can pick up the sounds that trees make.
Now, scientists may have found the key to understanding these particular cries for help.
In the lab, a team of French scientists has captured the ultrasonic noise made by bubbles forming inside water-stressed trees.
Because trees also make noises that aren’t related to drought impacts, scientists hadn’t before been able to discern which sounds were most worrisome.

The findings could lead to the design of a handheld device that allows people to diagnose stressed trees using only microphones.
Such a device may be particularly important as droughts become more common and more severe.

Across western North America, from Mexico to Alaska, forest die-off is occurring on an extraordinary scale, unprecedented in at least the last century-and-a-half — and perhaps much longer. All told, the Rocky Mountains in Canada and the United States have seen nearly 70,000 square miles of forest — an area the size of Washington state — die since 2000.

In 2005 Colorado researchers noticed that aspens were suddenly dying in large numbers. The die-off is called Sudden Aspen Death, or SAD.
It’s growing at an exponential rate – and killing not only mature trees, but the root mass as well.
An aspen grove is the offspring of a large single underground clonal mass, which sends up shoots.  “The whole organism is disappearing and it has profound implications,” said Wayne Shepperd, of the Forest Service. “When the roots die, groves that are hundreds or thousands of years old aren’t going to be there anymore.”

A study published in Nature last fall suggested that trees in many places—from tropical rain forests in South America to arid woodlands in the U.S. West—already “live on the edge,” meaning their cavitation rate is almost as high as they can sustain.
Sizeable areas of forest in Australia, Russia, France, and other countries have experienced die-offs, most of which appears to have been caused by drought, high temperatures, or both.

Shifts in rainfall patterns and increasing temperatures associated with climate change are likely to cause widespread forest decline in regions where droughts are predicted to increase in duration and severity