HOW do tree's circulate sap?

Discussion in 'Landscape Architecture and Design' started by clyde, Jul 10, 2004.

  1. clyde

    clyde LawnSite Senior Member
    Messages: 336

    I was just wandering how trees circulate the sap is it the sap comes up through the center and down the outersides under the bark or how exactly does that work?
  2. Turf Medic

    Turf Medic LawnSite Bronze Member
    Messages: 1,073

  3. fga

    fga LawnSite Silver Member
    Messages: 2,449

    interesting..........:) :confused:
  4. GreenMonster

    GreenMonster LawnSite Silver Member
    from NH
    Messages: 2,702

    Why? Do you think there is A maple tree on da island?

    I was down there last week Adam. I would have looked you up, but figured you were too busy crying in your beer after the sweep at Shea.

    See, that's the beauty of being a sox fan. Being on the losing end of a series sweep like that is something we're used to.
  5. gvandora

    gvandora LawnSite Member
    Messages: 143

    If memory serves me right you're looking for two types of vascular tissue in a dicot, which as far as I know trees are.

    The two types of vascular tissue are xylem and phloem. Phloem conducts sugar away from the leaves and to the rest of the plant. Xylem moves water up towards the leaves.

    Phloem is on the outside, it what makes a pine tree sticky when you cut it. The xylem is on the inside. It is partially dead tissue that remains and continues to conduct water upwards.

    This is a very basic explanation obviously. I'm reaching back to the fall of my sophmore year of college for all this. A basic botany book would probably be a good place to start for more info.

    Good luck.
  6. clyde

    clyde LawnSite Senior Member
    Messages: 336

    Yea i got my botany book


    i haven't looked at it in about 4 yrs though...
    where would that be? in the book that is ....

    so the cambian layer has 2 layers right? the out side of the layer is the Phloem and xylem is on the inside of the cambian layer. or is it the Pith?

    how does the food get to the pith if there are dead cells (wood) inbetween the cambian and the pith. and what is that called? the movement of food for storage

    So what this means is when a tree hollows its pith is no longer being restored and yet the tree lives because the cambian is on the outside.( which is the only living part) but how come it continues to live if it has not stored any reserves , is it because the roots have grown to the point that has intake contunously?
  7. KenH

    KenH LawnSite Bronze Member
    from CT
    Messages: 1,622

    In basic of basic terms, evapotranspiration of water from the leaves is what carries the sap up the tree, gravity carries it down. Think of standing a sponge up in a plate of water. The water will be carried to the top of the sponge. Same thing.
  8. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    You don't need a botany book. What you need is a plant physiology book, and a lot of eye rubbing!

    It should tell you something that when I say the there is only ONE undergraduate course in plant physiology at Purdue. I had to take it, it was required for my major. And there is a lot that I have forgotten! And probably even more that I didn't understand at the time.

    But KenH is right, the basic way water flows up from the roots to the leaves is by evapotranspiration. Trees are also able to "pump" water when need be, but, IIRC, that takes a lot of energy.

    The dead cells in the trunk of the tree continue to carry water upwards, usually for the life of the tree. On really hot days when there is a lot ot demand for water in the leaves, it is possible to break the flow of water through the cells, due to the extreme demand for water. It can happen, but not often. Once the flow is broken, it cannot be regained.

    Anyway, you asked a very complicated question, whether you knew it or not. If you want more information on it, try an internet search, or take a plant physiology class.... Hope this helped!

  9. mdvaden

    mdvaden LawnSite Bronze Member
    Messages: 1,946

    Wow.... Complicated....

    The tree sends the nutrients up to the top, through the inner tissue or xylem, to the top, where the leaves are.

    Then, the leaves make real "food" by photosynthesis, and send it down through the tree, down the trunk to the roots, through the phloem. The phloem is fairly close to the bark area near the cambium.

    That's why when a tree is girdled, the trunk swells above the girdle. It's because the inner tissue sends nutrients up, but the tree can only send food down as far as the strangling wire. So the tree is fed with real "food" from photosythesis down only as far as that food can travel.

    See how the trunk is larger above the rope because it was fed with photosythesized food?

  10. clyde

    clyde LawnSite Senior Member
    Messages: 336

    so what happens to all that food? when it hits the girdle
    does it drown the xleom or i should say saturate the ability for it to carry the crude sap up?


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