Tuesday 11 June 2013


I wrote yesterday about estimating the height of isolated urban trees: a sort of arm-chair puzzle for intellectuals who are happier to do their thinking on a sofa - or even, as I recommended at the end of yesterday's post, in bed asleep.  Even as I wrote, I had a nagging feeling that the creativity of my thinking teens was wholly eclipsed by some story that I'd read that was a) tree-related and b) Irish.  The Irish punch above their weight (Katie Taylor metaphors are so current) with nifty technology. For example, I was working in the lab next door when Identigen - perhaps Ireland's first-and-best biotech company - was born out of a  (never finished!) PhD project.

Treemetrics was born in Cork rather than Dublin and is the offspring of two Irish foresters Enda Keane and Garret Mullooly, who were fed up with cutting down trees.  Or at least fed up with cutting down trees wastefully and inefficiently.  They had spent too many wet days in the forest with a measuring tape and a pair of calipers getting dimensions from a sample of trees and extrapolating to the whole stand only to find that their current-best-practice technology was delivering woefully inaccurate and unreproducible results.  So they brought the technology from 19th to 21st century.
They take their measurements like a bat gets fed and process scads of data with some clever software that yields the key metrics that foresters and timber producers need: an accurate and reproducible assessment of the quantity and quality of the timber.  Bats use sonar pulses and big ears to detect the size and distance of prey to help them make optimal foraging decisions (one moth better than 6 midges) in the dark.  Treemetrics sets up a laser on a surveyor's tripod in a suitable part of the forest and sets it going for 10 minutes.  The timing of the return of each laser pulse gives 3D (x, y, z) coordinates for every piece of solid material within a 30-m radius of the laser. The software joins up the solid dots, ignores the fluttery bits and calculates the number of stems, their size, their height and their straightness.  It amuses me to imagine a John Henry race between the new technology and the old: by the time the feller-with-calipers is struggling through the brambles to his fifth tree, the Treemetrician is packing up to go home with the data on 500 stems.

New technology doesn't always win.  At the Annual Scything Fair in the Somerset levels, they have a scythe vs strimmer race.  The scythistas always insist that the strimmer has to start with his tool a) off and b) on the ground just like a scythe.  Each year the scythe wins comfortably - sustainably faster and much neater cut.  Sometimes new kit just becomes a rod to beat yourself with.  There are no moving parts to go wrong with a scythe, it works fine both before and after you drop it in a drain and it has a very low carbon footprint. Treemetrics tech is battery driven (8hrs life they claim) and presumably wouldn't fare well from a plunge in a forest pool but it clearly scales up. And you don't need the tripod if you have a Cessna, so Treemetrics can take measurements in really inaccessible places.

Trees grow to a pattern that is determined by genetics and environment, so I daresay that the raw data can be used to determine species of each stem in a mixed broad-leaf forest.  I was in Graduate School with a a real biologist called Chris Burnett who could identify the species of any tree by its winter silhouette.  If Chris can do it, I bet a few thousand lines of code can too.  Treemetrics?  Bri'nt!!

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