Bummer
The image is flawed
I think I know how to fix it to some extent. Where I claim "alive" it really should say "new growth" (Cambium). Tap-root 2 heart-wood = obviously dead wrong (poor assumption).
The Cambium layer I can easily discern. It is a very specific layer that almost looks like a golden-brown lichen when it is shaved form the blank. I'm pretty certain I am removing this layer as well when hand peeling the stalk. this is also the layer I think is most tannin-like.
I still want to know why the Phloem layer does so much damage to the core material after the normal life-cycle is disrupted. Do the radial marks also represent nutrition paths just reversed of what I was thinking? Meaning that the nutrition coming back from the leaves now feeds back to the core as it passes through the Phloem layer? Then yes, I can see a 'reversing' of this at the time of harvest.
There is no other explanation I can up with at the moment how blanks are drawing so much nutrition all the way from the core of the blank in such a short time.
I did learn about girding a tree by stripping the bark would or could kill the tree. Funny thing is, most of these stalks have no leaves. They may not actually be growing? They are soaking wet and fresh to within 2 inches of the last trimming some 4 feet from the root. Those live stalks trimmed years ago will have this environmental staining as you see in the image. Remodeling, staining, leaching are all evident in the end of the stalk. So one also has to wonder if the leaves from other stalks could be feeding these leafless stalks. What would reverse the nutrition cycle to make sure this otherwise lifeless stalk would receive food energy. Simply capillary action from the root-ball? Is the the plant's duty to maintain an average moisture content throughout?
So, in general we are dealing with this; Food in the form of carbon is sent through the Phloem layer 'downward'; and water and minerals are streaming upward through the Xylem (sapwood). In between these two networks is the Cambium layer which will become Xylem through seasonal cycles. If the carbon was no longer being supplied there is no reason to believe that the water and nutrition wasn't still flowing through the Xylem and leaching into the Phloem simply to keep it healthy for when new growth does occur and eventually provide leaves for the full cycle to resume. Therefore, I should be able to surmise that this bush has a mechanism to keep stalks alive when leaves are not present for bulk carbon conversion. Considering this shrub is designed to be trimmed to the ground every 3-4 years, growth and preservation is required with a photosynthesis response. New grown is a branch that can start anywhere along any remaining stalk. It takes a year to have a full shrub again. Normally these 4' stalks are a mere few inches above the ground.
Then again, I've had full fledged trees shoot up from a large cut trunk. This tells me there is a hierarchy to growth medium. Is it possible that the nutrition and water rising through the Xylem as far as it can go and have a return path through the Phloem when the species is truncated? Essentially making the carbon capture part of the food cycle only necessary for bulk growth. Or rather than look at these as end-termination, it is much more likely that this cycle happens at all elevations. Food source is flowing everywhere between these two mediums and that the leaves, providing photosynthesis resulting in carbon as a food source, will be distributed via the trunk as a reservoir receiving all the carbon before it is distributed throughout the species. Knowing if this transfer between layers is one way or bi-directional, my gut tells me that these specialized capillaries work in one direction while the species is alive. However, it is clear to me that leaving the Phloem layer on reduces the mass of the Xylem in short order where the lack of a Phloem layer reducing this mass loss significantly leaving only evaporation loss.
Man, never let a mechanical guy explain biology.
I don't think I am far off with the mechanism I am observing. Basically, the Phloem layer is still quite active in drawing nutrition from the Xylum layer as it does naturally. Whatever process is drawing the nutrition from the Xylum is arrested by removing the Phloem. That is a finding that has become clear through observation.
This piece has a month's seasoning. The shiny bit is what I strip the blank down too by hand. Could that be the Cambium layer (center of the image)? It is unique and very hard. Also has a waxy texture to it. That would make the soft matter peeling away Phloem. The Phloem layer is thick, particularly in ancient pieces. The actual bark is very thin backed with green, and a green smelling, membrane. ..."...could the stem of a plant mimic the leaf in Chlorophyll generation and thereby provide carbon through the stalks themselves?"...
And I do need to clarify a meaning because the syntax is completely wrong on the radial grain I see. It is a particular cell structure within the Xylum that allows for nutrient transport. I should look at them as interstitial radial layers along the grain. These are part of the nutrient transport mechanism.
Last interesting note;
Noting that Heartwood is hard is not quite the same in this instance. The center as shown in the upper picture would be fairly soft at harvest, very much like the outer Phloem. And like the Phloem, it darkens and hardens significantly as it takes on oxygen and/or age. I often don't see it until it reveals itself.
And once again
@Planck .... - seriously - thank you
@TheThriftDrifter - tracking says your country now has the parcel is moving it forward!
..and my pen blanks came in