Monthly Archives: January 2017

Are Trees Sentient Beings?

BEAUTY, GENERAL INTEREST, PRESERVATION

by Elsa Johnson

In an interview for Yale Environment 360, German forester Peter Wohlleben answers “Certainly”. And no, he doesn’t look like an Ent. Wohlleben argues that trees are wonderful beings with innate adaptability, intelligence, and the capacity to communicate with, and heal, other trees. How did he come to this Enti-ish belief?

As a forester, he says, he was trained to look at trees as economic commodities (I cannot resist an aside here: to wit — our culture does not value things unless they are commodities), but after joining an agency for a community beech forest in Hummel, Germany, he became disillusioned. He began to see the use of traditional commodity forestry – clear cutting, and chemical use, for example – as putting short term profits ahead of sustainability. Now he manages the forest completely differently. Distressed by these traditional forest management practices, he re-thought his position because he was someone who wanted to protect nature, and he was being asked to destroy it.

Gradually he learned that the individuals of a species actually work together and cooperate with one another. In his book The Secret Life of Trees, Wohlleben writes about how trees are sophisticated organisms that live in families. He uses the term “mother tree” to describe a tree that is at the center of an interconnected web of roots, that can distinguish whether the root it encounters is its own root, the root of another species, or the roots of its own species (this is crudely verified on our local level by our experience with the same species trees in Forest Hill Park succumbing to disease while different species trees close by survive it ). Wohlleben describes how trees pass electrical signals through the bark and into the roots, and from there into the fungi networks in the soil, and thus alert nearby trees to dangers such as insects, or disease. Trees can also learn he says, citing the example of trees that in the year after a drought took up less water in the spring so that more remained available in the soil later in the season.

Sometimes accused of anthropomorphizing trees, Wohlleben says “We humans are emotional animals. We feel things. We don’t just know the world intellectually. So I use words of emotion to connect with people’s experience.” And: “We have been viewing nature like a machine. This is a pity because trees are badly misunderstood.” And: “Nobody thinks about the inner life of trees, the feelings of these wonderful living beings.” And: “Plants process information just as animals do, but for the most part they do this much more slowly. Is life in the slow lane worth less than life on the fast track?”

Wohlleben offers the evidence that trees growing in undisturbed natural forest can beneficially affect climate change by reducing temperatures and helping the soil retain moisture under their vast canopy. Conversely, climate change adversely affects trees less densely planted, as in common practice in tree plantations. The extra CO2 in the air today is making young trees grow about 30%  faster than they did decades ago. The faster growth exhausts trees and makes them less healthy. Trees growing in undisturbed natural forest fare better, says Peter Wohlleben. They grow more closely together, causing humidity to rise, cooling the forest and helping soil retain moisture.

Ah, he loves his trees so much — maybe he is an Ent after all.

If you would like to read more of the interview with Peter Wohlleben, go to YALE ENVIRONMENT 360. The issue is 16 November, 2016. Yale 360 is an online magazine offering opinion, analysis, reporting, and debate on global environmental issues, written by scientists, journalists, environmentalists, academics, and policy makers (etc.). It is published by the Yale School of Forestry and Environmental Studies. The view and opinions expressed are those of the authors and not the school. 

   

  

Dreaming of Spring? The Peripatetic Gardener Reports on Her Travels

GENERAL INTEREST, PERIPATETIC

by Lois Rose

Cornell is located at the bottom of Lake Cayuga-far above the waters, right? It is approximately five and a half hours from Cleveland, a lovely drive if you take the cut off of 90 through the Southern Tier—mountains, valleys, rivers and streams—well worth it.

The campus contains a large number of gardens but my favorite is the Botanic Garden which includes ornamental and useful herbs, interesting vegetables, perennials, grasses, an amazing bioswale garden, containers and other displays of shrubs, trees, groundcovers.

Many of the herbs are displayed in raised beds, or elevated on the sides of the main garden.

 

Around every turn is something of interest, like the tree which has a hole cut in its middle, still living and producing huge leaves.(Catalpa I think). 

The drought over the months before we visited had taken a toll but there was still much to see.  Mediterranean plants, those that love the heat, were as happy as a clam in high water. 

Others had ostensibly succumbed and been replaced.  It takes several hours to really see everything in this space, including the containers crammed with diverse and unusual plants on display near the visitor’s center which incidentally has top notch merchandise much of it devoted to gardening.

Cornell is feverish on Saturday morning, and visiting the Farmer’s Market is a treat if you can find a place to park.

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Of Plants, Trees, and Soil: for Gardeners

Uncategorized

by Elsa Johnson

What is soil  (dirt!)  (earth!) – you know, that stuff plants (most of them) grow in — and how important is it, anyway?  

I’ll answer the second question first. Very important. At its simplest, soil is the stuff that feeds the green plants that create the atmosphere of our blue-green planet.  Soil is a creation, a product, the end result of a process.

We humans have a ‘thing’ for order and neatness. It is one of the ways we distinguish between the tended (hence, civilized; hence, reassuring) and the untamed (hence, wild; hence, threatening). It is the drive that compels us to pull up every unwanted plant, to prefer bare soil to – god forbid — a ‘mess’, to throw every bit of organic debris into a recycling bag for the city to come and fetch and take away.

Plants pull nutrients from the soil – and plants also create nutrients through their growth process. This is what we see above the soil – the growing plant and the soil around it. When the organic plant dies and decays in place, those nutrients go back to the soil, both above and below ground. With the help of insects and worms that take from the plant what they need for their own survival as they break down the plant’s fiber, this natural process builds a loose layer of topsoil. Soil is creation. We can help or hinder that. We all know that. But in the garden we have a hard time resisting our human need for order, for that look-of-civilization –and so, far too often, we take away all that good organic stuff that, if left, would enrich and rebuild our soils (for free) without doing any harm.  

In the forest the process works slightly differently. Tree leaves are fibrous and tough (if they weren’t we would be eating them). They don’t break down as easily or as quickly as soft-fiber garden debris. They decompose slowly, over a long time, resulting in a deeply layered forest floor of leaves in varying stages of decay, resulting in a deep, loose, dark duff under a natural leaf mulch that holds moisture and insulates the forest floor.

And this is just above ground.

Below ground soil is truly amazing, for in both the garden and the forest within that uninteresting looking ubiquitous soil exists a universe of diverse microorganisms, fungus, and bacteria with important jobs to do bringing nutrients, minerals, oxygen, and water to the roots of plants and trees. And a world of necessary microscopic predation goes on there too (for this is always the price life pays for life). That is healthy soil, sustained by and supporting the intricate, exquisite interrelationships of this complex, rich system. Intact, undamaged, these systems are self-sustaining. However, many of our common practices damage the soil.

All plants sequester carbon, as does oil, but exposing bare soil to air allows the soil to lose carbon into the atmosphere. Soil should be either planted or mulched.

Heavy equipment regularly and repeatedly rolling over the ground compresses soil, reducing its ability to absorb and hold oxygen and water, and also kills microscopic organisms that plants and trees need for health. Try to keep the use of heavy equipment to a minimum.  

Breaking up the soil by plowing or spading also loses carbon from the soil, and perhaps more importantly, breaks up soil structure, disrupting mycorrhizal structures and microscopic animals, and severing root connections and root interrelationships necessary for plant health.

Last — chemical fertilizers kill beneficial organisms, thus destroying soil health, and making plants dependent on repeat applications. Build soil health through composting and returning organic material to the garden.             

 

Overcoming Mushroom Timidity

PERMACULTURE

by Tom Gibson

Regular readers of this blog will have gathered that our personal Cleveland Heights home landscape can be fairly characterized as “bold:” Native plants with no grass in front and permaculture Food Forest plantings in back.  Some of the latter are pretty exotic—skirret , goji berries, even the oft- discussed native pawpaws .  But in one respect, we have kept the homestead “timid:” no mushroom cultivation.

We’ve just read too many stories of mushroom “experts” making fatal or near fatal (requiring kidney or liver transplants) mistakes. So we have carefully avoided either sampling the mushrooms that regularly emerge from our heavily shaded, oak-hickory landscape and have even remained reluctant to spread the spawn of mushrooms deemed safe.

That’s changed. It all began slowly.  A Food Forest seminar several years ago at Holden Arboretum left us with one sample inoculated shitake log.

(When the shitakes finally emerged, we ate them and survived!)  Then last fall I inoculated a patch of King Stropharia spawn underneath a stand of elderberries. This fall the distinctive wine-colored mushrooms popped up.   

We ate them and survived again!

Now, though, we’re moving much faster. The proximate cause: A course I took this fall at Ohio State University (“Mycelial Lectures”) that provided a broad overview of fungi and their natural role.  As part of that course, I combed both scientific and permaculture literature to write a research paper on “Maximizing Positive Fungal Power in the Food Forest.”

Here’s what we now plan:

  • Expansion of King Stropharia plantings to front and back yards and as companion plantings to vegetables in our community garden plot.
  • Inoculation of nameko mushroom spawn to as many fresh cherry logs as possible (a dozen?) to key companion planting locations in our Food Forest.
  • Inoculation of at least a dozen logs with shitake spawn.

We also plan to harvest maitake or “hen-in-the-woods” mushrooms which have been growing wild under our very noses for years without our knowing what they were.  

At this point the mushroom-savvy reader will no doubt want to place a hand on her forehead and shake her head in dismay.   What to us looked like ugly gray-brown eruptions on oak stumps are, in fact, widely sought-after delicacies!

Here’s what I learned from the course and elsewhere that has transformed my thinking:

  1. Of the 17 mushroom poisoning deaths reported annually on average in the U.S., 16 are due to the Angel of Death (amanita bisporigera) mushroom, which in its earliest stage looks like the edible porcini.   While other poisonous species can cause considerable damage, they tend to look quite different than the ones I plan to eat.  (Even the nameko,  which the very unwary might confuse with galerina marginata, is distinguished by clear identification points.  Or at least that’s what the literature says. Hmmmm… After looking at these pictures, I’m going to have study this further!)
  2. Fungal variety contributes to plant variety and productivity. (The reverse probably works, too, with plant variety contributing to fungal variety. But that point is, surprisingly, subject to hot scientific debate.) Most garden fungi are invisible to the naked eye, but are essential to the survival of most plants. They have co-evolved over millions of years to provide auxiliary root systems with special capabilities for scavenging hard-to-access elements such as phosphorous. This much I already knew. 

But what I learned in the course was how multiple combinations of fungal strains can lead to greater plant productivity.  Six fungal strains may contribute more together to a given plant than any one strain alone.  Moreover, plants select which fungi do the best job of providing them nutrients and reward them accordingly with more sugars.  (Lots of chemical intelligence in the soil that we’re just beginning to understand!)

  1. Study of fungal/plant interactions still leaves enormous gaps.  There is a tremendous amount no one knows for sure.  But intriguing companion planting anecdotes abound.  David and Kristin Sewak, the market gardeners who wrote the mushroom neophyte’s book Mycelial Mayhem, say, for example, that King Stropharia mushrooms thrive in the shade of tomato plants and stop late season tomato blight. I plan to copy their method in my community garden plot.  And the mushroom blog Radical Mycology reports that nameko mushrooms have a near miraculous effect on both growth and fruiting of neighboring woody perennials .  Thus my interest in namekos for my own Food Forest.
  1. The number one predictor of fungal species variety worldwide is precipitation. The lesson for the gardener is to never ever, ever let your landscape dry out: swales, mulch, watering—whatever it takes.   You experienced gardeners know that already, of course, but understanding one of the key “whys” reinforces motivation.
  1. The best way to ensure the productivity of most edible mushrooms—i.e., in the phylum known as basidiomycota, including the mushrooms you see pictured in this article and the puffballs below—is to have an adequate supply of calcium in the soil.   (I’m not sure yet what “adequate” entails, but I’ve been adding gypsum or calcium sulfate to support fruit set in my mini-orchard anyway, so I’m reassured.)

Longer term:

If fungal variety is so great for gardens, why not find a way to introduce more? Here systemic knowledge is also lacking.  Once established, many fungi are powerfully resistant to colonization by competitors. Yet some fungi valuable to humans and gardens alike, like King Stropharia, are known to spread aggressively.  Wouldn’t it be great to have the tools to perform a nuanced analysis of existing fungal populations and an equally nuanced set of guidelines for introducing sustainable populations of beneficial fungi to the soil? Maybe in 10-20 years….

And what about endophytic fungi?  This is a class of fungi about which I previously knew nothing. These are microscopic fungi that live within plant tissues, sometimes mutualistically, not as parasites.  Scientists have known about these fungi for over a century, but new tools for computerized genetic analysis have revealed their overwhelming numbers and variety. Many actually help their plant hosts either grow or ward off disease. Most plants acquire these fungi “horizontally,” the same way we catch flu. Studies have shown that suburban trees harbor fewer of these potentially valuable endophytes than the same tree species growing in native forests.  Could we make up that deficit in our gardens with foliar sprays of beneficial fungi?  Once again, maybe in 10 to 20 years.

Assuming that I continue to avoid eating toxic mushrooms, I’ll let you know then!

Reprise – Citizen Science in Forest Hill Park

GENERAL INTEREST, PRESERVATION

by Elsa Johnson

Last summer Gardenopolis Cleveland wrote about a project in Forest Hill Park undertaken by the Great Meadow Task Force for the East Cleveland Parks Association. The task force inventoried all the old growth trees (about 70 trees) in the park’s most iconic space, the Great Meadow, and with the help of Dr. David Roberts, a tree pathologist from Michigan University, arrived at the conclusion that the trees in the meadow are largely healthy and in good shape. However, as the summer wore on, it became clear that a group of 5 chestnut oaks about midway along the south perimeter access trail were showing signs of distress, with one clearly past saving.

How quickly this happened! It was shocking. The task force decided to invite Dr. Roberts back for a look at these trees, and at the trees in the area called the Meadow Vista, north across Forest Hill Boulevard. 

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Chestnut oak is an oak in the white oak group, native to the eastern United States, and an important ridgetop tree of the Appalachian mountain range chain, with a sparser outlier population in our northeastern Ohio foothills. Since most of us have never seen a chestnut leaf it will help to tell you that a single individual leaf somewhat resembles a beech leaf, but with small lobes, rather than fine dentations, and these gather together in a cluster.

Peeling back the bark on the dead chestnut oak tree revealed the grubs of two-lined chestnut-borers at about chest height.

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The borer starts its damage to the tree’s vascular system at the top of the tree, and works its way down. If only a few branches are affected presumably the tree could be saved, but when one finds the grubs at the base, the tree is definitely not salvageable. It is dead and should be removed and chipped (which kills the larvae). This borer is a serious insect pest of chestnut, white, black, red, scarlet, and bur oaks. Preventative treatment is possible, but treatment after a tree shows clear signs of decline is unlikely to save it.

Alas, this does not bode well for the park’s mostly oak forest. To prevent spread of this opportunistic insect in the Great Meadow (were there the funds to do so) these trees need to be gotten out of there.

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Then we all regrouped in the Meadow Vista, which has been suffering tree loss for a longer period of time than the Great Meadow; here many trees are diseased and dying. Examination of more recently dead trees here revealed chestnut borers in every affected tree. However, what Dr. Roberts was looking for was evidence of fungal pressure pads under the bark of dead and dying trees. He strongly suspected oak wilt here, based on the infection pattern he was seeing, with dead and diseased trees spreading in an ever widening ring from a center. And although we never did find pressure pads, but found lots of two-lined chestnut borer larvae, he remained concerned that oak wilt was also an issue here.

Oak wilt is an equally (or more) devastating diagnosis for our trees in the Meadow Vista. Where it might be manageable in the Great Meadow (were there the funds for treatment) in the more closely knit environment of the Meadow Vista and surrounding woods, management quickly becomes impossible as individual trees give way to densely packed forest… for oak wilt travels through the soil via the interconnected roots of same-species trees (i.e., red oak to red oak), and kills the vascular systems of trees through the soil, from the soil up. In an oak opening or savannah with some considerable distance between trees, one can cut trenches, severing the root systems, thus preventing spread. But where trees grow close together and the disease is manifesting in several locations, severing interconnected root systems is almost impossible.

The only good thing about oak wilt, and this is a very, very small thing, is that the white oak group succumb less often and less quickly than red oaks – and, indeed in Meadow Vista, all the affected trees are red oaks. Again, infected trees should be removed, chipped, and then covered for the year it takes to make sure the fungus is no longer viable.

What is the cause of so much disease? As I meet and talk with people in Cleveland Heights I discover other areas where oak trees have been lost to disease, or where there is failure to thrive. Is it stressed biological environments? How does a summer like the one we had in 2016 contribute to diseases like these? How do we plan a forest for the future? Another article will look at these questions.