How are these produced? I assume they're not actually digging a giant trench and taking a section, but are the drawings based on measurements of a specific individual in some way?
In any case, very cool to have such a collection.
In any case, very cool to have such a collection.
Modern methods like xray CT or ground penetrating radar can do it nondestructively in the field but they’re usually expensive to set up compared to just sending some grad students to dig.
At the very least, you've taken a 3D system and reduced it to 2D. Additionally, you're exposing not only the root system but the entire microbiome around them to light and, almost certainly, unless you were incredibly meticulous about sealing, oxygen.
But yeah, that's what I mean.
The traditional way of transplanting large trees while keeping the root system intact is with a hydrovac. A machine the size of a jet engine that liquifies the soil with water and then vacuums it up. [1]
More recent developments have tried using an AirSpade which doesn’t use water but compressed air to blow apart and then suck the soil without making a slurry which is better as the soil can be redeposited in the same hole rather than discarded[2]
Air spades in particular are primarily used for rootwork, not transplanting. Bareroot methods are used for smaller trees. Bare rooting leaves roots in a very vulnerable state, so doing it on larger trees you intend to move and keep alive is a serious logistical challenge.
The most traditional method I can think of is "ball and burlap" where root balls are cut free in the field, and retrieved later in the season for final packaging.