Tree trunk water movement (check up from the neck up)

[M.D. Vaden]

I need to keep reviewing this...

When "sap" moves down in a tree in fall / winter, isn't that downward movement to the roots in the phloem?

Seems to me that for the trees to avoid dehydration, that the xylem must still send some moisture upward.

I'm estimating that the dripping from a pruning cut on a maple right now in December is water from xylem that was moving up and out to the branch that was removed - not sap that was moving down xylem.

Feedback?....

Guy...? Anyone...?

 

[Stumper]

Moisture is moving practically all the time(well maybe not in Wintertime Canada). Seriously, the roots are growing when the soil temps are over 40 degrees F. Sap movement is taking place in the wood. Buds are growing all winter. If it weren't for the natural sap movement then Sunscald wouldn't be such a problem in some species in this area. Sap "going down" and "coming up" seem to be more like Folk euphemisms for early dormancy and post dormancy than scientific accuracy to me. For that matter-Dormancy is only a relative term- the trees do a lot of "tossing and turning" in their "sleep".

 

[Tom Dunlap]

From what I've read there's very little movement of water "down" the tree. Also, the starches don't move very far either, the shuffle around a little though.

There are some new models being developed from research that seem to change our ideas of water moving in tubes. The stuff that I've read is a bit over my head.

This link might be the one that gets me banned from AS for life, if so, such is life. It's too Treelink, an organization that I have NO connection to other than having spent some time talking with Pepper. It's non-commercial and non-profit too.

Look around and you should be able to find links to some current research and links to the Journal of Arboriculture research papers. There should be a search feature to find stuff in the JA archives.

http://www.treelink.org/

 

[Stumper]

Great link Tom! Fret not-that site isn't commercial and certainly doesn't "compete" in any way with AS.

 

[TREETX]

Dr. Tatter at U Mass?? Did a bit of work in this area. I haven't spoken with him in a while though.

Back then he was being paid to speak by Mauget.

The Rainbow guys should have boat loads of info in this area......

 

[John Paul Sanborn]

There has to be some translocation of carbs from the leaves to the roots or they would not be able to grow. There allso has to be some amount of storage in the roots or we would not have maple suryp in the spring.

Yes the majority of the starches stay local, but taper shows that it moves down the stem and gets allocated as it moves (Mathecks Ratio for critiacal failures a good proof)

Most movement of fluids is fascilitated by transperation, but allso needs uptake, so there is little movement if the ground is frozen and the leaves are off.

I have heard that there is local activity on warm days where photosynthesis is happening in bark, and winter burn is a good example of fluid movement without proper uptake in evergreens.