The Hatchet


In 1906, one year after the first and only Tree Planting Day on the WashU campus, the University Yearbook adopted this logo.

An incredible day today in the University Archives and Special Collections. A complete privilege to be paging through the original Olmsted campus plans, the adopted Cope & Stewardson plans, the failed campus competition entries, and the early 20th century tree inventories. Special thanks to University Archivist Sonya Rooney for her introduction to the collection and invaluable assistance.

Certainly more to come….

Under the soil, life


Last week we began our inquiry into tree life under the ground with a careful, suggestive introduction to root/fungus relationships with biologist and plant ecologist Scot Mangan. A specialist in what he describes as the ‘biology of dirt,’ Scott introduced into our conversation a range of ways to understand the mutualism of mycorrhizal relationships as well as the selectivity of fungal pathogens. Ecto-mycorrhizal associations are those tuned to the sort of oaks we are working with, as we follow a range of issues related to differential allocation, root architecture, and basics of sub-surface growth. In the photo above, Scott leads a discussion in reading the possible signs of the presence of mycorrhizal  associations as we view the stunted, blunt growth of fine roots.



There are a number of different ways in which one can produce a model of a tree, and we have explored many of these as a group. One particularly interesting class of “tree model” is the mathematical model. Within this class, there exists a substantial variety of approaches, but the idea, in general, is to replicate tree morphology with an algorithm. I chose to begin my exploration of mathematical trees via L-Systems (named after biologist Aristid Lindenmayer who first proposed them).

L-Systems are a type of recursive string-rewriting system that are capable of, among other things, drawing 2- and 3-D branching patterns. You can read all about them here. Even while remaining totally deterministic, i.e. without introducing probability or randomness, they are capable of producing some pretty convincing plants:


More to come.

Arboreal Convening

onetree_treeworkaheadWe have been studying the biological functioning and ecological interrelationships of a tree, but they also exist as uniquely social and legal objects in the landscape. For whom does a tree do its work? What work, exactly, is it doing? And who is responsible when it fails? Trees relationship to law, risk, and property confer a unique sort of status to the public nature of ownership, and challenge some of the more abiding categories of boundary definition and maintenance.

There is a certain poetry in the ambivalent language of risk: imminent, probable, possible, improbable. These are the categories of contingency that an arborist brings to their assessment of a tree. Duty of care speaks to the legal pact we enter into when we plant and maintain a tree, as we dance around the threshold of the probable and the possible.

David Gunn of the Missouri Botanical Garden ascending tree with double rope technique.

The conversation and field-session was led by a cast of the region’s top tree experts: Skip Kincaid (former Commissioner of Forestry for the city of St. Louis, now with Hanson’s Trees), Ben Chu (Horticulture Supervisor at Missouri Botanical Gardens), Kent Theiling (Horticulturalist at WashU), Bill Spradley (President of Trees, Forests, Landscapes), David Gunn (Arborist at Missouri Botanical Gardens), and Russel (Forestry Division of St. Louis). In addition, we were joined by ecologist Doug Ladd, artist Marilee Keys, biologist Scott Mangan, and outdoor educator Guy Mott. A sincere and resounding thank you to all!

Weathering a February flurry, as Ben Chu narrates the climb.


Introduction to a Tree


Wonder is a function of the degree of resolution—in birdsong, in optics, in philosophy, in theology.

-Charles Foster, “In Which I Try to Become a Swift”

Doug Ladd, until recently the Director of Conservation at Missouri Nature Conservancy, led us on a wide-ranging, foundational conversation on the meaning and biology of trees, and the abiding link between temperate forests and humans. Treeness, he argues, is best understood as a morphological definition of something that conferred advantage. Here, he skipped from tree to carnation to dandelion to draw out a point on adaptation, and the increased fitness through natural selection. The conversation took us through the ancient Quercus prelobata, oak fruits, cache trees of woodpeckers, green tree reservoirs, apical dominance, and cellular senescence, and forward through our own Quercus palustris and their native flatwood habitats.

With an initial, deceptively simple prompt to construct a model of a tree, Doug in fact introduced into the discussion two questions: what is a tree, and what is a model. Here, the question of relationships–of the network of associations that allow something we call a tree to emerge in the first place–proved to be crucial. As we sketched and annotated our clumsy tree diagrams, questions of reproduction, fungal associations, structural stability, water and nutrient exchange, and habitat were all teased out of the conversation. The model of one tree quickly gave way to the idea of a vast biological system that happens to include a tree.

The Tree Itself

I contemplate a tree.

I can accept it as a picture: a rigid pillar in a flood of light, or splashes of green traversed by the gentleness of the blue silver ground.

I can feel it as movement: the flowing veins around the sturdy, striving core, the sucking of the roots, the breathing of the leaves, the infinite commerce with earth and air–and the growing itself in its darkness.

I can assign it to a species and observe it as an instance, with an eye to its construction and its way of life.

I can overcome its uniqueness and form so rigorously that I recognize it only as an expression of the law–those laws according to which a constant opposition of forces is continually adjusted, or those laws according to which the elements mix and separate.

I can dissolve it into a number, into a pure relation between numbers, and eternalize it.

Throughout all of this the tree remains my object and has its place and its time span, its kind and condition.

But it can also happen, if will and grace are joined, that as I contemplate the tree I am drawn into a relation, and the tree ceases to be an It. The power of exclusiveness has seized me.

This does not require me to forego any of the modes of contemplation. There is nothing that I must not see in order to see, and there is no knowledge that I must forget. Rather is everything, picture and movement, species and instance, law and number included and inseparably fused.

Whatever belongs to the tree is included: its form and its mechanics, its colors and its chemistry, its conversation with the elements and its conversation with the stars–all this in its entirety.

The tree is no impression, no play of my imagination, no aspect of a mood; it confronts me bodily and has to deal with me as I must deal with it–only differently.

One should not try to dilute the meaning of the relation: relation is reciprocity.

Does the tree then have consciousness, similar to our own? I have no experience of that. But thinking that you have brought this off in your own case, must you again divide the indivisible? What I encounter is neither the soul of a tree nor a dryad, but the tree itself.

–Martin Buber, I and Thou

[with special thanks, and endless respect, to Chesney Floyd for this reference]

Smart Pin Oak Reproduction Strategies


Pin oaks rely on animals to help them reproduce. The reason while their nuts are with think shells is because in this way squirrels would be more attracted to their fruits. These squirrels are not smart enough to remember where they hide their food, and then the survival of pink oak nuts will spread out to other places further than their “mother” is at, and the species gets the chance to move further.

tool : finding

the relationship of the tool to its corresponding finding
Shigo notes that the lightweight chainsaw made possible longitudinal sections, or dissections, of injured trees; he made over 15,000 in a 25 year span.
He found that the discolored wood varies in size, color, and degree of moisture — and shows a relationship to the external wound.
From the longitudinal application of chainsaw to tree, a very particular internal reality of the tree is revealed — albeit violently. Concepts of discolored and decayed wood and heartwood were subsequently developed — but we humans are still knocking from the outside.
(reference: Alex Shigo, A New Tree Biology)