+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Drought and the Impact on Sap Production

  1. #1
    Join Date
    Nov 2021
    Location
    Ma
    Posts
    54

    Default Drought and the Impact on Sap Production

    Good afternoon All-

    Anyone have any ideas on how a significant drought like we have been experiencing globally but more specifically in the North East impacts the sap production. Does less ground water force the trees to work differently in producing sap? I would like to hear your thoughts.

    Thank you

  2. #2
    Join Date
    May 2009
    Location
    UVM Proctor Maple Research Center, Underhill Ctr, VT
    Posts
    6,391

    Default

    Sap flow is more dependent on soil moisture during the spring itself...so snowmelt and rain during the spring are quite important. However, there seems to be a couple of impacts on sap sugar content and tree growth. Think of leaves as the engine of the tree. The fuel is sunlight. But in order for that engine to run at peak levels, everything else needs to be operating correctly. If soil moisture is lacking, stomates in the leaves close, so CO2 cannot enter the leaves and be "fixed" into sugars. So drought reduces photosynthetic carbon gain (production of sugars), resulting in reduced growth and less storage or sugars in that ring of wood formed during that time. Fortunately, the sugar we collect as maple producers in sap comes from many tree rings (20-30 depending on tree growth rate and taphole depth), but the outermost tree rings tend to be the most productive (more sugar and higher hydraulic conductivity...meaning the younger pipes/vessels work better), so there can be some small reduction in sap sugar content due to drought. This is more apparent when we have several years of drought in a row.

    I apologize if this seems too complicated...but that is really the simple explanation. The details would make heads spin.
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  3. #3
    Join Date
    Jan 2020
    Location
    Connecticut
    Posts
    159

    Default

    So it sounds like we might get lower sugar content. Will this affect the amount of sap as well? Or should we get roughly the same amount of sap, but less sugar? I know there are many many other factors to consider, but all other things being equal.
    Thanks - Becky
    2017 - 20ish taps on buckets, boiling outside in two baking pans
    2018 - 70+ taps, 14-buckets, 50+ on tubing, homemade arch from oil tank in my barn, 17 gal syrup
    2019 - same set up, 20 gal syrup
    2020 - less taps, short season, but RO kit was fantastic! 6 gal syrup and a maple cat!
    2021/22/23 - expanded into the neighbors yards! 50 taps on buckets and 40 taps on tubing

  4. #4
    Join Date
    Jan 2006
    Location
    Oneida NY
    Posts
    11,547

    Default

    The amount of sap depends on soil moisture in the spring, like Dr Tim said, snowmelt and rain leading into and during the maple season
    Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
    Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
    Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
    After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.

  5. #5
    Join Date
    Feb 2022
    Location
    Essex Junction, VT
    Posts
    276

    Default

    Is there a point at which, one should look at the summer drought conditions and decide, for the long term sake of your sugarbush, skip a year? It sounds like some folks have already made that call for this coming season. (or maybe it was just one folk. Someone mentioned it)
    Last edited by Andy VT; 09-16-2022 at 07:39 AM.

  6. #6
    Join Date
    Jan 2008
    Location
    Hopkinton, MA
    Posts
    1,778

    Default

    Personally, I'm not going to skip a year based on this year's drought. I've had years where the sugar content is lower, but the volume of sap due to good conditions in the spring is very high. I've also had years where the sugar content of the sap is higher, but the conditions in the spring have led to a short season with low volume. I'd much rather have the former.

    I've only been at this since '06, but in that relatively shorter time I've had a few serious droughts and two years of really bad gypsy moths. Each time I expected a direct impact on sugar and it didn't seem to materialize - at least in an obvious way. The other thing I've found is sugar production is really micro-regional. My area (eastern Mass) is in the the worst drought in years, but my trees appear to be far less stressed than previous droughts. I've had Augusts and early Septembers where the leaves are spotty and dropping in big numbers. This year there's been some leaf drop but not as bad as previous years. Maybe there was enough rain in the early part of the summer to get the trees through. I have no idea.

    All that said, I will skip individual trees if I notice it's not doing well, especially if it's young. I had a big dead oak taken down this summer (gypsy moths) and they had to limb some 10" sugars pretty heavily to get to it. I'm going to give those trees a year off.
    Woodville Maples
    www.woodvillemaples.com
    www.facebook.com/woodvillemaples
    Around 300 taps on tubing, 25+ on buckets if I put them out
    Mix of natural and mechanical vac, S3 Controller from Mountain Maple
    2x6 W.F. Mason with Phaneuf pans
    Deer Run 250 RO
    Ford F350
    6+ hives of bees (if they make it through the winters)
    Keeping the day job until I can start living the dream.

  7. #7
    Join Date
    Feb 2016
    Location
    Peru, Maine
    Posts
    1,044

    Default

    After a couple of relatively dry springs, we had a normal one with some rain this year. Definitely noticed it helped to keep the late season runs going. Longest season in a few years this past year. Don’t worry about the summer drought.
    305 taps on 2 Shurflo's, 31 taps on 3/16" and 229 taps on gravity. 565 in all
    Mountain Maple S3 controller for 145 of the vacuum taps
    2x6 Darveau Mystique Oil Fired Evaporator w/ Smoky Lake Simplicity Auto Draw
    Wesfab 7” filter press

  8. #8
    Join Date
    May 2009
    Location
    UVM Proctor Maple Research Center, Underhill Ctr, VT
    Posts
    6,391

    Default

    Quote Originally Posted by therealtreehugger View Post
    So it sounds like we might get lower sugar content. Will this affect the amount of sap as well? Or should we get roughly the same amount of sap, but less sugar? I know there are many many other factors to consider, but all other things being equal.
    Thanks - Becky
    Sap yield has more to do with the conditions happening during the spring flow season, particularly soil moisture and temperatures.

    Sugar content is related to a whole bunch of things...drought being one of them. It is difficult to accurately predict given the large number of variables involved and their interactions, but we have done some work on this.

    In general, again, if you think of the leaves of the trees as an engine, that engine will run at its peak efficiency if all things are going well. If something impacts the performance, sugar production will decrease. Not a lot you can do to INCREASE production (other than thinning, perhaps fertilization) to make the engine better, so most stresses act to reduce engine (photosynthetic) performance to varying degrees. Many are interrelated...so when it is hot, it is often dry. But then you're also factoring not only one growing season, but a large number of them, but with decreasing levels of effect on sap sugar content as those tree rings get deeper into the tree.
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  9. #9
    Join Date
    May 2009
    Location
    UVM Proctor Maple Research Center, Underhill Ctr, VT
    Posts
    6,391

    Default

    Quote Originally Posted by Andy VT View Post
    Is there a point at which, one should look at the summer drought conditions and decide, for the long term sake of your sugarbush, skip a year? It sounds like some folks have already made that call for this coming season. (or maybe it was just one folk. Someone mentioned it)
    Generally no. Tapping is such a minor stress in most cases. If there were 2-3 years of significant drought, and there were areas that we particularly prone to drought (shallow soils, stony soils, ridgetop sites, ledgy sites, sandy soils, etc.) and it was possible to not tap those trees for a few years...then by all means...go for it. Most people don't have that option.

    Typically decline disease happens due to the combination of 2 or more factors, so something like drought will impact the trees, then some insect or other stress will finish them off. This process generally takes several years. The trees may recover...or not.

    Tapping only removes on the order of 3-4% (max) of the sugar reserves from a tree each spring. The exception to this rule is SMALL trees. In the understory they're living on starvation wages (low light), and barely growing. Any removal of sugar is detrimental.
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  10. #10
    Join Date
    Feb 2018
    Location
    Canaan Valley, WV
    Posts
    220

    Default

    Quote Originally Posted by DrTimPerkins View Post

    I apologize if this seems too complicated...but that is really the simple explanation. The details would make heads spin.
    it was a great explanation! Now I am curious to when the trees are most susceptible to drought conditions We had a very dry June and July, but then it rained almost every day in August. The leaves have been turning color here but they seem to be a week or two behind in color what they normally are at this time which is interesting... Also, usually the red maples are the first to start turning then sugars. This year they are about the same time.

+ Reply to Thread
Page 1 of 2 12 LastLast

Posting Permissions

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