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Maple Events on the Horizon

Join Associate Professor, Dr. Stephen Matthews to learn about USDA Forest Service’s Climate Change Atlas.  He will introduce this tool that is based on over 2 decades of research with a goal to help us understand the impact of climate change on our trees. When you have heard us talk about red maple’s favorable position in the face of an uncertain future, the work of the Climate Change Atlas is what we are drawing from.  Register for the April 12th webinar HERE.

Future Generations University is offering a webinar this Thursday evening, March 21st at 7 PM.  The Appalachian-based program Out of the Woods hosts guest speaker Dr. Catherine Belisle (Cornell University) and Lindsay Kazarick (Future Generations University) to discuss maple confections and event-based marketing. REGISTER here.

Here’s a little bonus video to enjoy featuring Cornell University’s Arnot Teaching and Research Forest in New York.

SAVE THE DATE for 2024’s Ohio Maple Days – December 7.  We will be shifting locations this year due to a scheduling conflict at our normal venue at Ashland University.  You can look forward to this year’s Ohio Maple Days landing at Wooster’s Secrest Arboretum.

And speaking of events, we hope everyone got to participate in Ohio’s Maple Madness Tour.  Whether by opening up your own operation to visitors or by venturing out on the tour yourself, Maple Madness is a signature springtime event that should not be missed.  We hosted somewhere just shy of 100 folks throughout Saturday, March 2nd at the Ohio State Mansfield campus.  Thanks to all who came, and a BIG THANKS to everyone who led tours of the wetlands, sugarbush, and kept the evaporator steaming all day long.

 

Tapping & Timber: Monthly Maple REVIEW

After a several months long hiatus from our REVIEW articles, we are going to dive back into a Quebec research 2’fer that examines the effects of tapping on sugar maple tree growth rate and timber accumulation.  The Ohio State Maple team hosted a day’s worth of Maple Madness as a stop along the Ohio Tour less than 48 hours ago.  While giving sugarbush tours, hands down the most frequent question I fielded was whether tapping hurts the trees.  While some research has attempted to answer this question over the past decade or so, 2 relatively new studies out of Quebec take aim on this subject.

The question “does tapping hurt a maple tree?” can be answered from multiple different perspectives.  You might respond by citing information about the small percentage of a maple tree’s overall sap that is harvested through the tapping process, even with a high vacuum system.  You might make an analogy that a taphole is similar to an insignificant injury and point out that healed tapholes are barely visible to the eye just a year or less later and the percentage of compartmentalized wood is miniscule.  You might have another way of replying to that question.  The article “Effect of tapping for syrup production on sugar maple tree growth in the Quebec Appalachians” and the paper “Assessing the effects of sugar maple tapping on lumber production” provide additional insights to this delicate topic.

Before we dive in, a few caveats:

  • Caveat #1 – this issue has been addressed by different studies through different research labs through time, I’m examining these 2 studies today because they are recent and both from the same geographic area, Quebec.  Perhaps we will address some of the other work conducted in this space in future REVIEW articles.
  • Caveat #2 – The studies are from Quebec.  Stated another way, these studies are not directly applicable to Ohio, but we can certainly learn from them regardless.
  • Caveat #3 – both studies are based on tapping recommendations that encourage tapping to begin when a tree is 7.5-9.1 inches in diameter.  This recommendation in comparison to more conservation guidelines that we teach locally of 10″ minimum before tapping layered in with the fact that growth productivity is higher in Ohio than Quebec, and we have additional reason to not assume 1 to 1 transferability of results.

The study that focuses on tree growth rates was conducted by a foursome of researchers (Ouimet et al.) back in 2021.  They examined tapped and untapped trees within 7 Quebec maple woods on vacuum tubing systems.  The normal stringent criteria were applied to ensure trees in each group were as similar as could be except for the main treatment variable: tapped or not tapped.  Ouimet and crew worked off a primary hypothesis that tapping sugar maple trees would remove enough of the non-structural carbohydrates (sugars) that tree growth rates would be higher in untapped trees versus tapped trees.  Restating their hypothesis another way, extracting sap from sugar maples is in direct competition with resources needed for tree growth.

What did they find?  In 6 of the 7 sugar bushes, there was no effect of tapping on tree growth rates.  In the 7th site however, tapped trees grew 33% slower over the tapped year period (10 years) than did the untapped trees.  A partial explanation seemed to be that soils in that particular forest were strongly Ca-deficient; however, similar decreases in tree growth rate were not observed in 2 other woods that also suffered from low Ca levels.  Truth to be told, the team was scratching their heads a bit over the inconsistent results stating the “relatively small NSC [non-structural carbohydrates] allocation to syrup production might explain why we did not find a consistent tree growth response to tapping.”  In the most elementary of terms, tapping did not seem to trouble the majority of trees in the study.

The second study coincidentally also featured a four-person research team, and the research utilized data from 17 different sites within Quebec’s public forests.  Forest stand management scenarios (how and when to harvest trees) and lumber yields were simulated using a model that gathered data from over 2 thousand individual trees.  If taphole-stained maple lumber does in fact have niche value in local and regional niche markets, I would quibble with blanket statements such as the one they provide in the Introduction citing the National Hardwood Lumber Association – “Tap holes are considered defects, and they diminish the manufacturing value of boards.”  But the purpose of the work is clear, does tapping affect traditional lumber value of sugar maple logs?


Photo: Firth Hardwood Export Logs

What did they find?  Unsurprisingly, the answer is yes.  Of course tapping reduces net lumber volume in sugar maples, and tapping reduces the probability of an individual tree yielding a 10 foot saw log.  The details are what I found especially interesting.  Trees in the study were binned into 4 different health categories.  Trees with fungal infections, rot, or noticeable crown dieback were impacted by tapping more than trees that were healthy by visual measures.  While this too is unsurprising, I was most impressed by the findings that tapped sugar maples have a 85-90% chance of still yielding a 10′ saw log.  However, net lumber volume is still markedly reduced by tapping as the vertical segment of the trunk sectioned by the lowest and highest tapholes (or “butt log”) is defect.  Guillemette et al. concede in the very first paragraph of the Discussion that their results do not account for “craftspeople sometimes use these butt logs to produce boards with specific features resulting from tap holes or stain.”  I appreciated this admission.  Even so under a more traditional notion of what is valuable maple lumber, a notable rule of thumb emerges from their Implications for Management.  “Tapping reduces the net standing volume of sugar maple timber by approximately 40% and reduces the harvestable volume after the first 30-year cycle by approximately 40%.”  Economic modelling of one-time profits due to timbering need to be compared to the year-over-year return on investment from sugaring a maple woods, but the study does provide some interesting ways to frame and think about our original question – does tapping hurt a maple tree?

Ohio Maple NPR Soundbyte

You are never quite sure how a piece of media coverage will turn out after a couple of hours of interaction gets boiled down (yes, that’s a pun) to 4 minutes and 30 seconds.  But I’d say the NPR creative machine did a great job churning out something engaging that highlights work across the state from the past, present, and even into the future.

This is as good of a time as any to remind everyone of Ohio’s Maple Madness weekends on March 2-3 and March 9-10.  You can scan the following QR code off your monitor or visit the Tour Map to plot your own route.

At Ohio State Mansfield, we will be hosting our Maple Madness event on Saturday, March 2nd – we hope to see you there.  Come hungry!

Mid Season Update & Cornell’s Maple Climate Network

Our sap season at the OSU-Mansfield sugarbush is well underway after tapping trees beginning January 29 and officially collecting sap by February 1.  While I still have time to change my mind, my current belief is that we nailed the “When should we tap” question with the right answer this year.  Our first run was a solid week long with solid nightly resets below freezing as this forecast basically fulfilled itself just like the weather prognosticators predicted.  Though overall sap volume was not as productive as it could have been, sap Brix started off at 2.1 and stayed ready right around 2.0.  By the end of the first run and through roughly Valentine’s Day, the woods got downright crunchy and dry highlighted by a few days that pushed temperatures almost up to 60 F.  During a second run of several days, flows remained average at best but Brix still hovered at a good sap: syrup making ratio.

As far as growing degree days go, we are almost exactly halfway to seeing silver maples break bud, and the rest of February and first couple days of March as currently forecast will likely push us right up to that threshold.  If I had to guess, we will be shutting off a couple main lines that are heavy “Rilver” (red x silver hybrids) in the March 1-5th range and hoping for another week or two production out of our sugar maples.

While there are a few nights with temperatures forecast for the low-mid 20s, it appears the OSU-Mansfield sugarbush will spend more nights above freezing as February drags into March.

Checking forecasts further north in towns like Chardon, Middlefield, and Geneva, all the way north to Ashtabula on the lakeshore, most nighttime temps are currently sitting on the wrong side of 32 Fahrenheit and the next 2 weeks offer only a few opportunities at hard overnight resets to stimulate good sap flows.  What March holds in store, I certainly don’t know.  And if another great sugaring weather pattern emerges, will our taps still be putting out lots of high quality sap if and when that occurs?  What I do know is this – Mother Nature has always and will continue to be the one holding the cards.  Even if my hindsight is happy with our initial tapping dates and I don’t eventually wish for a do-over, that is still no guarantee of a banner season.

As this year’s season ticks along, we’re excited to have an Ohio maple producer in Geauga County hosting a tree monitoring system for Cornell’s Maple Climate Network database.  You can track various metrics, such as Total Sap Production, Atmospheric Pressure, Tree Pressure, Rainfall, and Soil Moisture on this Dashboard.  Just look for the legend indicator so you can focus on some Ohio data and watch the season unfold from a single sugar maple tree’s perspective.  A great project with lots of potential, we’re glad Ohio can be a small part of the effort.

Buckeye Teaching Evaporator: The First Boil!

Exciting developments at the Ohio State University-Mansfield campus!  We installed a teaching maple evaporator under our new pavilion near the research sugarbush and just completed our first boil last night.  This step is fairly monumental for Ohio State Maple, and there isn’t anything quite like the feeling of seeing that first draw-off.  Somehow we’ve got a grainy image of that moment last night to commemorate the experience!

First things first – a formal thank you to Roger and Suzie Gortner for continuing to do our production sap processing.  They have made exceptional maple syrup from our OSU trees for the past 5 years and will continue to be instrumental in that regard.  We literally could not do it without them, and we’re grateful that it’s an arrangement that works for both parties involved.

But now for the first time ever, we have our own evaporator.  No, it is not sized to keep up with a production woods of almost 1,200 taps, but it is perfectly sized for demonstration boils on a teaching scale.  With help from local producer Galen Smith from Mount Vernon, OH, our team set up an 18” x 66” drop flue evaporator early in winter of 2023-24.  After a test boil to dummy out a few variables (or maybe to dummy out the dummies…us!?), we put fire under sap concentrate on Wednesday, February 14th – Valentine’s Day.

Four 5/16″ lines kept sap flowing from our larger sap tank into a holding chamber that our reverse osmosis unit was drawing off.  We adjusted the PSI on our RO to almost perfectly sync and match the raw sap movement with our RO processing speed.  After some adjustments to align the 2 processes, we were taking sap from 2.1 to 4.6 Brix concentrate.  6 hours later, we were halfway there…

Eventually, we crept up to 7 degrees F over the point of boiling water.  You know what happens next.

A teaching evaporator with small-scale RO unit allows us to now teach via-demonstration tree-to-bottle workshops and seminars on an Ohio State campus, provide more complete tours for events like the upcoming Maple Madness event on Saturday, March 2nd (more on that in a second), and sets the table for a new Sustainability Theme GE course debuting in Spring of 2025 – Maple: A Sweet Taste of the Past, Present, & Future.

So yes, come visit us on Saturday, March 2nd at the OSU-Mansfield Maple Pavilion.  We are excited to host folks for pancakes and syrup between 10 AM-1 PM, tours of the sugarbush and nearby vernal pool wetlands all day long until 5 PM, and good fellowship with one another for the Ohio Maple Madness Tour.  Once you are on campus, just follow the signs!

We Are Tapped!

We had a great turnout of folks to help tap maple trees on Monday and Tuesday at the OSU-Mansfield sugarbush.  A big thank you to Anthony Tambini and Rachel Coy – both former students who worked in the maple woods and returned for a fun day of tapping!  My gratitude to Marne Titchenell who appreciates maple amidst the larger sphere of wildlife, her Extension expertise.  Thank you Chelsea and Kris, current students who are working for me this semester.  Of course, Carri and Jake were there helping as always, and it was great to have Katie Gerber, one of ODNR’s State Service Forester, who came to get some hands-on maple experience too!  Many hands make light work and we are planning to shut the sap tank valve first thing in the morning and officially start our production season.  Happy sugaring to everyone already tapped, and may your crystal ball of weather forecasts and prognostications be clear if you are still trying to decide when to tap.

SLF Sap Survey – Citizen Science Opportunity

If you are a maple producer located within 25-miles of a confirmed spotted lanternfly detection (and we have a good mailing address for you…big caveat!), you should be receiving an SLF kit in the mail today or certainly by the end of the week.

That kit will supply you with some helpful identification resources, a pickled SLF adult to call your very own, a postcard asking for a few Brix value readings from your maple trees, and a QR code link to an instructional video.

If you do not receive a citizen science kit, but you still want to participate, please do so.  We would be honored to have you contribute.

First, download this file of the SLF Postcard (PDF).

Second, watch this instructional video.

Third, collect as much data as you can during your 2024 maple season.

Fourth, seal up your printed datasheet in an envelope and mail to me at:

Attn: Gabe Karns
Sch of Env & Nat Resources
2021 Coffey Road
210 Kottman Hall
Columbus, OH 43210

As always, if you have any questions or concerns, please reply to this post or shoot me an email at karns.36@osu.edu.

 

A Little Science behind Maple Sugaring Weather

Hands down, the number one question that comes up this time of year is “When should I tap?”

Due to the warmest December on record, I have heard a few Ohioans even asking “Should I have tapped in December?”.  When you look back over the years, the trend has been toward earlier tapping dates, but hoping that you can keep taps open for 3+ months is a bit of a stretch.  There is no way that will happen on a gravity system, and you will need more than a little luck even on high vacuum.

The scientific approach to planning involves studying climatological data and developing a plan based on that data. The maps below are long range weather predictions for the next three months. You can clearly see that all indications point to above normal temperatures for the next three months. For sugar makers what does this mean?

To quote a good friend and fellow maple researcher, “when you look at forecasts you need to look at it from the big producer / small producer perspective.”  Because most small producers tap everything at one time, they need to consider the value of a good short-term, 30-day forecast.  In most cases, especially if you are on a gravity system, you need to find the best 30-day window that will allow you to make the most syrup.  Once you tap, you are on the clock and that clock runs out shortly after 30 days.  On the other hand, if you are a large producer or even a medium producer on vacuum, you need to study yearly trends.  Trends will disclose what has happened over the last 3 to 5 years.  What we have seen is a trend to earlier tapping just about every year.  In most cases, early tapping has paid off in Ohio.  A major reason is that newer technology lends itself to pushing the envelope when it comes to tapping.  You have the advantage of running a semi-closed vacuum system utilizing 24/7 operation.  This lengthens your season considerably.

One of the most valuable pieces of data you can use are temperature history graphs for your location.  Weather Underground has some of the best.  They plot the maximum, minimum, and average temperatures.  Plotting the maximum and minimum will give you a good idea on the number of freeze-thaw days to anticipate for a month.  As we all know, freeze-thaw cycles are very important and drive daily sap runs.  You can look at these cycles over a five or even ten year period.  Over time you begin to see how various weather patterns play out.

Keeping in mind these are zip code specific but we are talking at the broad scale of an entire state, here are three February graphs. You can clearly see we started February leaving a warm end to January on two out of the three graphs.  In all the graphs, conditions continued to warm up as February wore on.  In two out of the three, the temps dropped going into March.  This may be a hint for what could happen this year.  2020 and 2022 were almost normal.  In both cases, our records show average to above average production.  2021 was the outlier and production was down for that year as temperatures stayed warm through most of March.  The other two years highlight the fact that starting out February warm does not mean you will march into March warm.

Too much science?  Here is a more common sense approach that prioritizes the size of your operation.  If you are tapping thousands of taps, you must start early to get the job done.  For a moment, think about a huge 50,000-tap operation.  Should they consider tapping right after the first of the year?  Definitely!  One of their strategies is to tap 5,000 taps super early.  This results in the Facebook posts you may have seen bragging about syrup being made over Christmas.  Several big producers in the East did this in December.  Does that mean they tapped everything?  Most likely not.  A large commercial producer hedges their season by tapping some early and the rest over the month of January with everything in the tree and ready by February 1.  Small producers who are setup to boil early can also do this, the only difference is they may start tapping their early running trees shortly after New Year’s but plan to finish out in February.  This keeps fresh taps in the system and prevents you from putting all your eggs in one basket.  The best way to accomplish this is to keep very good records.

That brings us back to our initial question.  When should I tap this year?  All indications are that we are going to have a warmer than normal winter.  If you are in Southern Ohio, you might be tapped already.  North of I-70, you should probably hold back until the end of January.  This is where analyzing the 30-day forecast is critical.  Studying several long-range forecasts a little closer, I noticed that we may have some of the coldest weather of the winter on the last week of January and the first week of February.  While the forecast is showing a warming trend coming off several weeks of genuine cold weather, depending on your situation you may even want to hold off until the first week of February.

Of course, the joker in the deck is the El Nino weather event we are experiencing.  El Nino’s are known for extremes and all it takes is a bend in the jet stream and you could be looking at 10 more days of below average weather.  Once this happens, you usually go right back to the warmer than normal pattern.  In this case, cold weather is your friend.  What we do not want is 10 days straight above normal!

As for my prediction!  I will tell you what kind of season we had in 2024 on the first week in April.  May your sugar season be long and sweet.

Anyone Tapping Yet?

When to tap?  That is the question.  And when it comes to maple sugaring, that is THE question.  Currently, we are in the holding position at our Mansfield sugarbush and thankful for the cold temperatures that have descended on the region.  The longer the woods stay cold, the closer our trees will get to meeting their chilling requirement, and the more optimistic I will be when we do eventually start our season.  Put simply, if trees don’t sleep well, they can wake up cranky!

When we look to the south along the Ohio River, I see more good signs of zero accumulated growing degree days since the start of the year.  Note, this does not account for any warm spells we had around Christmas.

With that map in mind, a peek at online chat forums like the Maple Trader’s Ohio Forum reveals that several folks are already tapped in part or in full (January 2nd in Ross County, another early report out of Muskingum County).  Looking even further south to states like Kentucky and West Virginia, only early tappers were rewarded with last year’s ultra-warm and sporadic 2023 season.  That likely pushed some producers to move their tapping date earlier on the calendar.  Still, others are crossing their fingers that last year was an anomaly and going with a more traditional schedule again for 2024.

Taking the forecast up top at face value and speaking directly to our Mansfield site, there aren’t many (if any) quality freeze-thaw cycle days for a truly big run in the next 2 weeks.  If we do decide to tap in a week or so, we should at least get all our lines flushed and spot check the vacuum on the system while we wait for better conditions to kick things fully in gear.

Come back next week for a post from Les Ober where he discusses the question of tap timing and the effects of El Nino as we all wring our hands and stare into muddy crystal balls in search of the right answer to our question!

Updates from the Sugarbush

Based on the forecast, it’s hard to tell when our season will launch at the Ohio State Mansfield campus, but we’ve been hard at work readying the woods for whenever Go Time is.

3 years of single tree lateral lines came down from the ACER project that examined differences between sap production in Freeman’s (red x silver or “Rilvers”) maples.

Lateral lines in bad shape from wildlife damage or sanitation issues were replaced.  Some of these issues are pretty small and hard to spot unless you have your vacuum pump running.  Other wildlife damage…guessing raccoon or coyote here, pretty obvious.

Bucked rounds were hauled and split to feed our new demonstration evaporator at the also brand new maple pavilion (more on that later!).

We’re nearly done replacing all of last year’s spouts.

As we find drops and T’s that need replaced, we are shifting to a pin- or peg-style T so that we cut off the old spouts when taps are pulled at the end of season.

New trees that have grown into a minimum tapping size have been added to the system.  Surprisingly, our second main line that originally featured 99 trees when the tubing was installed in 2019 grew by 9 additional taps this year.  This was a good reminder to keep a diameter tape handy when getting your sugarbush ready for the season.  Sure, trees grow slowly, but they are growing and it’s sometimes surprising what just a few years can do when conditions are right.

End-line sensors are out gathering sunlight to keep our monitoring system operational, and we’re adding valves to the end of our main lines to facilitate a more complete and convenient sanitation regiment.

And our invasive species contract to control multiflora rose, particularly where it was worst along main lines 1 and 2, is already paying dividends with increased mobility and ease of access throughout the system.  A chest-rigged brush cutter was used to sever stem clusters in tandem with a timely and targeted application of glyphosate to the cut stem surfaces.  **This is a good reminder that any herbicide treatment in and around a working sugarbush should be done with caution!  Being cognizant of compound half lives, targeted treatment that stays where it belongs, and a well-trained applicator are keys to ensuring these sometimes necessary steps help and don’t hurt.**  Honestly, having the ability to freely negotiate through the woods wherever we please probably contributed to finding 9 additional taps along our second main line.  I also couldn’t help but notice that the majority of our lateral sanitation issues were cropped up around the second main line too.  Certainly trickle down penalties of thorny access because of a nasty invasive thicket infestation in the woods!

You literally could not walk through this area of the forest before, and the stem clumps that are left (and hopefully dead!) are the reason why.

One last major priority for this off-season will be attempting to remedy the long flat (at best!) stretches of main line between our pump house and where the majority of our taps start on main lines 4, 5, and 6.  I’m sure that will be a learning process complete with a couple of bumps in the road, but the goal is to perhaps install a couple lift options to show producers different ways of overcoming this common challenge in Ohio maple woods.  More on this last point later!!