Tree Root Chandeliers

Humus_photo_Aad Hogendoorn
photo credit: Aad Hogendoorn

Italian artist Giuseppe Licari displayed his site-specific art installation named “Humus” at Tent Rotterdam museum in 2012. These Hanging roots made the central place of the museum become a “mysterious underworld”.

Humus - foto Job Janssen & Jan Adriaans_LR
photo credit: Job Janssen & Jan Adriaans

This landscape changed our view of the materiality of the trees and to start using it as a medium of creativity. In the meantime, it changed the way we see the space that we occupy and the space we couldn’t have occupied.

photo credit: Aad Hogendoorn



Tree Public Art in Rotterdam

tree public art

Along the canal in Rotterdam, there are many public artworks. This one particularly about one tree definitely stands out, as it seems trying to tell us a story about the tree’s past by preserving it through support by its other fellows in other species.

I thought this could be a great inspiration for our potential public artwork about one tree, that the story behind a tree does not need to only about its current life, but its memory is also worthy to discover.


Tag and measure, measure and tag

Spencer Finch, Walden Pond (surface/depth), 2013 mixed media installation

IN this work, Finch has re-recorded the 102′ depth of Walden Pond (first and last recorded by Henry David Thoreau), correlating its latitude and longitude with aqueous colors in 700 readings along a mariner’s sounding line, complete with terminal lead plummet. The tied red marks here designate every foot—instead of the traditional order of 2, 3, 5, 7, 10, 13, 15, 17, and 20 fathoms. (Intriguingly, mariners’ lines were shaped so that they could be read by eye, or by touch in the dark of night.

“Neither entirely documentation nor sculpture, the long line may best be considered a drawing of Walden Pond.” -James Cohan Gallery

As Rob has posted previously, is our drawing the root, the trench, or the displaced soil itself? The root we’ve uncovered may itself be thought of as a record of that soil—with all of its stones, pockets of air, and patches of nutrients, invisible to our sight and evasive of the touch of our hands. Scientific tools could help us correlate the root depth to porosity/compaction, to soil nutrients and fertilizers and competition. What would the tool be for measuring depth when it comes to ground—a plumb bob? A forester’s dbh tape, then, for the diameter of the root compared to the last measurement. An accounting of the number of branching moves and their direction relative to the tree, or to true north by means of a compass. Soil color at horizon depths could be measured as well as depth and trend—as Margot has noted, we are as designers drawn to correlates of color and their potential for variation. Curiously, there are no means to measure the passage of time in root growth. Is the map of root time in its corresponding branches above, their terminal bud scars from the year before yielding proportional information?

Or could our soundings be the points of variation from a lateral, level expectation: trend reversals from thick to thin to thick again; the doubling-back, the circling, and the backwards-forking, thwarting our lateral anticipations? The rooting behavior is more akin to creation of a networked mat with socialist tendencies than a set of hierarchical root structures. Would further abstraction make this more explicit? Would circuits and nodes rather than lines come to inform our understanding?

Like Finch’s drawing, ours might combine the visible and measurable, the analog and the digital, art and science. Our rendering(s) might reveal what underground truths we are separated from and create correlates to our sensory experience, thereby mitigating, at least in part, our soil blindness to the underneath.

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.