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Interesting. This might be explained by the switch from old growth to new growth^. Older trees would be larger, and have more core to work with (I think knots a

by zizee 5y ago

Interesting. This might be explained by the switch from old growth to new growth^. Older trees would be larger, and have more core to work with (I think knots are mostly from the outer layers of the tree). ^ this is pure speculation

brimble 5y ago
That would be my guess for at least part of the reason, too, but it'd only be a guess. I also wouldn't be surprised to find out that tree species plays a role, and that we plant species for harvest that simply produce worse lumber than what used to be widely available (as old growth).
irrational 5y ago
The core (heartwood) is the worst part of the tree. Now the trees are harvested so young that the entire things are junk heartwood.
- deleted 5y ago
  [deleted]
- mauvehaus 5y ago
  The sapwood is an approximately constant radial dimension over the life of the tree once it gets big enough to form heartwood. Sufficiently old trees are more heartwood by percentage than sapwood. For hardwoods, it's typically the heartwood that's more desirable. Walnut and cherry both have pretty strongly contrasting sapwood that does not match the customer's expectation for the color of those woods, for instance.
mauvehaus 5y ago
It's a little more complex than that. You get branches (which manifest as knots in boards) where there's sunlight that can reach the leaves on the ends of those branches. Trees grown among other trees have to grow up to reach sunlight. The innermost part of the lower trunk might have knots from branches when the tree was young, but once they reach harvestable size, there's a fair amount of clear lumber down low. Trees grown in the open don't have the pressure to grow upwards, and end up with branches down low throughout their lives (from the center all the way through to the bark). As a result, there's very little clear lumber in them. Disclaimer, I'm a furnituremaker, not a forester. The above is somewhat better than pure speculation, but likely misses some important bits.

by zizee 5y ago

brimble 5y ago

That would be my guess for at least part of the reason, too, but it'd only be a guess. I also wouldn't be surprised to find out that tree species plays a role, and that we plant species for harvest that simply produce worse lumber than what used to be widely available (as old growth).

irrational 5y ago

The core (heartwood) is the worst part of the tree. Now the trees are harvested so young that the entire things are junk heartwood.

deleted 5y ago
[deleted]
mauvehaus 5y ago
The sapwood is an approximately constant radial dimension over the life of the tree once it gets big enough to form heartwood. Sufficiently old trees are more heartwood by percentage than sapwood. For hardwoods, it's typically the heartwood that's more desirable. Walnut and cherry both have pretty strongly contrasting sapwood that does not match the customer's expectation for the color of those woods, for instance.

mauvehaus 5y ago

It's a little more complex than that. You get branches (which manifest as knots in boards) where there's sunlight that can reach the leaves on the ends of those branches. Trees grown among other trees have to grow up to reach sunlight. The innermost part of the lower trunk might have knots from branches when the tree was young, but once they reach harvestable size, there's a fair amount of clear lumber down low. Trees grown in the open don't have the pressure to grow upwards, and end up with branches down low throughout their lives (from the center all the way through to the bark). As a result, there's very little clear lumber in them. Disclaimer, I'm a furnituremaker, not a forester. The above is somewhat better than pure speculation, but likely misses some important bits.