IMG_5713.JPGThe first iteration of the tree enclosure has been dismantled, but not without leaving its mark.

Keep an eye open for the next iteration.


Tree Sounding


How do we gain access to tree-ness? How are symptoms diagnosed from within the inaccessibility of a tree–its history, its girth, etc? These are some of the broader landscape forensic questions we have been asking throughout the term.

This past week we worked with the German physicist, inventor, and tree expert Frank Rinn to begin to map the interior of a tree using sound.

Yup, sound.

Frank has invented and manufactures a system for sonic tomography–the measurement of a tree’s cross-sectional density by means of sound-waves. IMG_5407

With a girdle of 15+ sensors, the tree is sounded in a sort of arboreal perambulation–where each sensor is lightly tapped 5 times as the propagation time of the sound wave is  measured at each of the other sensors. The resulting measurement is a map of the speed of sound through the medium of the tree.


Each vector in the chart to the left measures the relative time it took for the sound wave to reach a corresponding sensor. The resulting diagram of greens, oranges, yellows, pinks, and reds, is simply a visual coding of speed–with green being relatively fast, and red/pink being relatively slow (or nonexistent).

This set of measurement is then interpolated to form a density map on in the tomogram on the right. Here, a visualization of the wood density–and, perhaps, through experience in interpretation, strength–is charted in a communicable form.

As Frank is quick to point out that, while this tomographic system certainly communicates fundamental scientific information about the trees in question, this sort of imagining is fundamentally a political tool. In the politics of the visible, and in the politics of urban street-trees in particular, the ability to communicate the non-visible, the subcutaneous, allows urban foresters an immediate way to construct a slightly more informed landscape public.

At stake in this sort of measurement is the politics of diagnosis. Landscape is uniquely interpretable as a symptom: a symptom of ecological pressures, historical processes, and design intents. The traces of these (geo)histories, embedded as they are within the body of the tree, provide symptoms that can be diagnosed through a range of landscape forensic activities. Much of what we have been up to in this course is exactly this. Landscape forensics as method.


Listening to a Tree

Provoked by questions surrounding the nature of sound in/through/among trees, we completed our first auditory exploration on tree C7 in the allee. Carefully working through the layers of bark until we encountered the living matter of the tree, we carved a 4 inch square hollow in which to place our listening device. This device is an ElectroVoice Model 805 Crystal Contact Microphone, circa 1950 (incidentally and coincidentally,this exact model of microphone has apparently been used on trees before to record beetle movement!).


The first tests frame the tree as a resonator, planting the microphone within the hollow and recording the output with a zoom mic. Using a mallet on the bark we circumscribed the tree with a series of taps moving first away from the mic and returning to it from the other side. This exercise produces a few new ways in which to draw/diagram the tree. The recorded audio itself (with some simple noise reduction applied) places us in the sonic space of the tree. The spectral frequency of this recording also allows us to understand the tree in a new way.

C7_spectral frequency

What does the attack, decay, sustain, release profile of these mallet strikes tell us? Can the heartwood be read from the signal? Or does the variation simply indicate the difficulty in maintaining a consistent signal from point to point? Thirdly, the dance around the tree with the mallet serves as a diagram. Certainly much more can be mined from this first test. The next step will be to frame the tree as an articulator, listening for the sounds the tree itself produces, especially as it begins to wake from it’s winter slumber.

Root Excavation – Day 04


As our unearthing of the root continues and we contend with grafts, elbows, changes in pitch, and buried infrastructure (!), we are also grappling with this act of ‘drawing’ upon the site. Is our drawing the root, the trench, or as Alisa insightfully noted, the displaced soil itself? What is the assertion put forth by our delineation of the root, of the tree, of the site? Who is this assertion for? Laura Kurgan in her fantastic book “Close Up at a Distance: Mapping, Technology & Politics” cites Rosalyn Deutsche in discussing this entanglement of representation/reality/politics.

Reality and representation mutually imply each other. This does not mean, as it is frequently held, that no reality exists or that it is unknowable, but only that no founding presence, no objective source, or privileged ground of meaning, ensures a truth lurking behind representations and independent of subjects. Nor is the stress on representation a desertion of the field of politics; rather, it expands and recasts our conception of the political to include the forms of discourse. We might even say that it is thanks to the deconstruction of a privileged ground and the recognized impossibility of exterior standpoints that politics becomes a necessity. For in the absence of given or nonrelational meanings, any claim to know directly a truth outside representation emerges as an authoritarian form of representation employed in battles to name reality. There can never be an unproblematic—simply given—”representation of politics,” but there is always a politics of representation. 

Laura Kurgan, Close Up at a Distance: Mapping, Technology & Politics, (New York: Zone Books, 2013), 18.


Digging Drinking and Droning

Allow me to introduce B-5. That is the name of our tree, perhaps not our One Tree, but the tree we are most interested in for now. Its tall and sturdy above ground, but the unseen  – whats below the bark and underneath the soil has been a mystery. By following the root, from root flare at the base of the tree trunk out until we reach the end of the root, we can observe the extent to which tree canopy has any correlation to root spread.  This is an experience of slowing down time – many hands and many hours later, the one tree root is still not exposed. Could you imagine the entire allée coming down by man power only? No machines, just simple hand tools and shovels to relieve the trees from their medium. This is a process of upheaval. While we are engaging with these trees as a living laboratory, we are also participating in the unhurried disassociation of a tree and its environment. Every hole, every accidental slice of a root, every footstep that increases soil compaction affects this tree’s next calculated measure to prepare for its steady future. Does it know it does not have a future?



The Allée Ballet


A moving section through the allée from east to west. As the ground slowly rises, the ghosts of people and cars flash in and out of existence, while overhead the watchful trees explode like fireworks, all in a carefully choreographed display of shifting, moving, pulsing, life.

Pressure Relief


An unexpected gush of tannin filled liquid streamed out from our Haglof Borer. The smell, a reminder of our rotting tree-forts from childhood. And the taste? Obligatory, raw, but rancid the way cow manure smells like fresh air.