+ Reply to Thread
Page 3 of 8 FirstFirst 12345678 LastLast
Results 21 to 30 of 76

Thread: Does the loss of sap or damage from tapping impact long term health of trees more?

  1. #21
    Join Date
    Mar 2008
    Location
    Lake County Ohio
    Posts
    1,628

    Default

    A little something for the "for what it's worth" department.

    There's a Northeast Ohio member here with the following in his signature;
    "Tapping the same trees my great, great and great grandfathers tapped".

    So... If we allow 25 years per generation, that gives us 100 years; guessing this member is 30 something gives us 130 years of tapping these same trees. Estimating that these trees were close to 50 years old before they were tapped and we have a bush with 180+/- year old trees - still healthy and still producing. Assuming these older fellows were using 7/16" taps - and maybe even putting 3-4 per tree, we now have 180+/- year old healthy trees that have been tapped for 130 years using older technology.

    With all of that said; in the past four weeks, this bush and this member, have produced 53 gallons of syrup to date, on 225 buckets and 50 gravity lines. He produced 127 gallons in 2010 and I can only guess he uses 5/16' spouts now. The numbers and the history are impressive and speak loudly for the sustainability of producing maple syrup and the tenacity of the sugar maple. These men have obviously taken care of their woods.

    I am not supporting vacuum or gravity one way or the other - I just don't know enough yet - and I have a lot of respect for what the good Doctor has to say about his chosen field. As for the long term effects of tapping, whether we should be on gravity or on vacuum, and how many taps are acceptable I for one, respect his opinion.
    John Allin

    14x18 Hemlock Timber Frame Sugar House 2009
    Leader 2x6 w/Patriot Raised Flue Pan 2009
    Leader Steam Hood 2014 - Clear Filter Press 2015
    Leader Revolution Pan and SS Pre-Heater 2016
    CDL Hobby RO & Air Tech L25 Hi Vac Pump 2019
    06' Gator HPX to collect wood & sap
    14' Ski-Doo Tundra for winter work in the woods
    Great Family 3 grown kids+spouses and 7 grand kids who like the woods
    7th Gen Born in Canada - Raised in Chardon Ohio - Maple Capital of the World..<grin>.

  2. #22
    Join Date
    Feb 2011
    Location
    NE PA
    Posts
    1,564

    Default

    Hi John , I don't think there is a person here who that does not respect Dr Tim or appreciate his willingness to answer our questions. I am sure that he gets many of the same questions from his students. We are all learning and very fortunate to have Dr Perkins here from time to time as a very knowledgeable and most generous sounding board.

    If no one has said it lately, Thank you Dr. Perkins

  3. #23
    Join Date
    May 2009
    Location
    UVM Proctor Maple Research Center, Underhill Ctr, VT
    Posts
    6,390

    Default

    Quote Originally Posted by Snowy Pass Maple View Post
    Maybe the part of this discussion worth exploring is whether (2) 5/16" wounds are equal, better, or worse than (1) 7/16" wound.
    Clearly worse. 1 7/16" spout = 1X wounding, 2 5/16" spouts = 1.6X wounding. Internal wounding is 60% higher with 2 small spouts than one large spout.
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  4. #24
    Join Date
    Feb 2012
    Location
    Salt Point, NY
    Posts
    185

    Default

    Quote Originally Posted by DrTimPerkins View Post
    Clearly worse. 1 7/16" spout = 1X wounding, 2 5/16" spouts = 1.6X wounding. Internal wounding is 60% higher with 2 small spouts than one large spout.
    Hi Tim -

    I'm curious to understand better why you say 60%. On simple cross-sectional area, if my math is right, I believe the two 5/16 spouts are equal to a single 7/16. While on simple diameter, you could say the two small spouts total diameter is 43% more. Is there another critical dimension that determines this or am I not thinking about this correctly? Beyond simple dimension, I also wonder is it better to have a larger hole that takes a longer time to close and has a larger volume impact to the tree in one place vs. two smaller holes that close up faster? Feel free to point me to any references of interest that already explain this stuff :-)

    For now, I'm just playing it safe with single 5/16" all around - getting plenty of sap to keep me busy!

    By the way, I also see birch producers talking about using 7/16" - but then resting the trees for two years. Any reason you're aware of why they should not just use 5/16" taps if there is already a perceived higher sensitivity to damage when tapping birch?

  5. #25
    Join Date
    Feb 2011
    Location
    NE PA
    Posts
    1,564

    Default

    snowy- go back and read the link Dr Tim left in post #18. I believe that will answer all your questions. The section that speaks to internal damage found on dissection explains it. The internal impact area where wounding occurs from a 5/16 tap is about 80% of that of a 7/16 tap. This goes beyond the simple cross sectional dimensions of the tap itself. Thus the 1.6 value given to wounding from 2 small taps is 60% greater than the wounding from one large tap (which would have a wound value of 1)

  6. #26
    Join Date
    May 2009
    Location
    UVM Proctor Maple Research Center, Underhill Ctr, VT
    Posts
    6,390

    Default

    Quote Originally Posted by Snowy Pass Maple View Post
    I'm curious to understand better why you say 60%.
    Happy answered this one (and you're welcome).

    By the way, I also see birch producers talking about using 7/16" - but then resting the trees for two years. Any reason you're aware of why they should not just use 5/16" taps if there is already a perceived higher sensitivity to damage when tapping birch?
    The exudation (flow) mechanism is very different in birches, and arises from root solute loading (with sugar) causing water to be drawn in from the soil, creating a high root pressure. We are not (yet) certain whether vacuum will augment sap yield from birch trees.....but we're working on it. In addition, the compartmentalization in birches is not as strong, so the wounds can be bigger. As they say....it's a different animal (or plant in this case).
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  7. #27
    Join Date
    Feb 2012
    Location
    Salt Point, NY
    Posts
    185

    Default

    Quote Originally Posted by happy thoughts View Post
    snowy- go back and read the link Dr Tim left in post #18. I believe that will answer all your questions. The section that speaks to internal damage found on dissection explains it. The internal impact area where wounding occurs from a 5/16 tap is about 80% of that of a 7/16 tap. This goes beyond the simple cross sectional dimensions of the tap itself. Thus the 1.6 value given to wounding from 2 small taps is 60% greater than the wounding from one large tap (which would have a wound value of 1)
    Quote Originally Posted by happy thoughts View Post
    snowy- go back and read the link Dr Tim left in post #18. I believe that will answer all your questions. The section that speaks to internal damage found on dissection explains it. The internal impact area where wounding occurs from a 5/16 tap is about 80% of that of a 7/16 tap. This goes beyond the simple cross sectional dimensions of the tap itself. Thus the 1.6 value given to wounding from 2 small taps is 60% greater than the wounding from one large tap (which would have a wound value of 1)
    Oops - I missed that link - very nice paper! This stuff just gets me more and more interested in the hobby :-)

    What caught my eye even more was the tapping depth analysis. That seems pretty compelling as well - first time I've seen it quantified like that.

  8. #28
    Join Date
    Feb 2011
    Location
    NE PA
    Posts
    1,564

    Default

    snowy- I read some other papers on tapping depth a few weeks ago. I believe they were older works out of UVM, though their authors escape me. They did some pretty interesting stuff including making large horizontal cuts through a tree to see how sap flow in the rest of the tree would be affected. No surprises there on depth, deeper holes mean more sap but a lot more internal wounding. And if you do some basal pruning on your maples, they're gonna die.

    And on a somewhat related note, though the thought of certified organic maple syrup really annoys me because most syrup would qualify as "organic, I understand there are additional stipulations for certification re sustainability that I'd be interested in. Anyone know what those might be offhand? Do they address what size spile, how deep, and how many?

  9. #29
    Join Date
    Feb 2012
    Location
    Berkshire, VT
    Posts
    76

    Default Study shows greater wounding with vacuum than gravity

    I noticed something that was not correct for a gravity situation in Dr. Perkins posts above. The study conclusions on gravity were that the wound of a 5/16 spout was 59% of that of a 7/16 spout, not 80%. The 80% figure was for vacuum, not gravity. So the math above is 7/16 wounding = 1, 5/16 = 0.6, two 5/16 = 1.2, sap yield of 5/16 = 0.94 of that of 7/16 on gravity. So two 5/16 would yield 1.88 as much as one 7/16 for 1.2 wounding. That is a very different yield vs wounding calculation.

    The discussion that a second tap yields only 50% more sap involved vacuum systems, not gravity. That makes sense, since vacuum pulls from more of the tree's sap column. Gravity, as explained in posts above, does not. So a second tap is more likely to yield twice as much.

    I understand that Dr. Perkins' focus is on vacuum systems, so the figures for vacuum are in his head more than the figures for gravity. In this thread we are concentrating on gravity systems, which are a different animal from vacuum systems. I'm fascinated that the wounding is significantly different from gravity to vacuum, gravity wounding of the 5/16 tap being 60% and vacuum wounding being 80% of the 7/16 tap. So vacuum systems have a direct cost in tree wounding beyond any sap extraction cost.
    Last edited by Vermont Creation Hardwood; 03-04-2012 at 02:34 PM. Reason: plural verb needed

  10. #30
    Join Date
    Mar 2011
    Location
    Live in NY, Sugarhouse in Milton VT
    Posts
    133

    Default

    Quote Originally Posted by Snowy Pass Maple View Post

    Maybe the part of this discussion worth exploring is whether (2) 5/16" wounds are equal, better, or worse than (1) 7/16" wound.
    I think the paper addressed this for smaller trees somewhat - If I read it correctly then the view seems to be that for small diameter trees it is probably a bad thing. I won't speculate f beyond that.

    We tend to err on the cautious side - and I might start drilling more shallow as well.

+ Reply to Thread
Page 3 of 8 FirstFirst 12345678 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts