There’s been a lot of thinning along Francusdreef near the Chaussée de Waterloo. Larch is being culled. The Larch is not native, these trees were planted for commercial exploitation but the drift these days is restoration of the Forest to a native biosystem.
It does give a chance to play detective. What can we learn from the rings, the very heart of the tree?
Here’s a fresh cross-section of a larch trunk, probably around forty years old, and it reads like a diary written in rings.
First thing you notice: those rings are tight, regular, almost disciplined. That tells you it spent its whole life in a uniform plantation block, neighbours all around it. Larch is competitive but polite so if the canopy stays closed, it stretches upwards and doesn’t bulk out too much. And sure enough, there’s no great surge of thick rings anywhere, so the foresters clearly didn’t do many thinnings here during the past four decades. No sudden “ah, finally, some light!” years.
People often look for wind signatures in a trunk like this, expecting the centre to be pushed off to one side by decades of prevailing gusts. Not here. The pith sits almost dead-centre, only the slightest nudge in one quadrant. That’s not wind; that’s simply a bit of extra light from one direction. If wind had shaped it, the whole section would be lopsided and carrying a structural lean. This one stood straight and steady.
And then there’s the colour. The inner part is a deep, warm brown, the outer much paler, almost golden. That isn’t staining or odd behaviour — it’s perfectly normal. You’re looking at heartwood and sapwood.
The darker heartwood is the older, non-living timber, loaded with resins and extractives that give larch its toughness. The lighter band around the outside is the still-living sapwood, carrying water and nutrients right up to the crown. Larch makes a very sharp contrast between the two, and on a fresh cut it shows dramatically.
Look closely and there’s also a slightly tighter run of rings halfway through its life which corresponds to known data from 95-97, a sequence of 3 slightly drier years.
No fire scars and also no browsing damage, a non-native species is not a good food source for insects and larger fauna. Just forty years of steady, modest growth among its peers.