New research indicates predictor for syrup crop.

[batsofbedlam]

For decades, maple syrup producers have eyed the weather to help understand spring sugar yields. But new research in the journal Forest Ecology and Management reveals a more valuable metric for understanding – and even predicting – syrup production: how many seed helicopters rained down from the trees the year before?
"Weather affects how much sap will flow out of the tree, but sap volume is only one piece of the puzzle," says Josh Rapp, who as a postdoctoral fellow with Elizabeth Crone, associate professor of biology at Tufts University and senior author on the paper, analyzed the factors influencing 17 years of maple syrup production at 28 sites in Vermont.
What really matters to maple syrup producers, Rapp explains, is the amount of sugar in the sap: "Sugar maple sap is 2 to 3 percent sugar. The rest is just water to boil off. Sweeter sap is more profitable. If you start with sap that's 3 percent sugar, it takes a third less sap to make a gallon of syrup."
So, what predicts how much sugar is in the sap? "Not weather," says Rapp. "Weather alone was a surprisingly bad predictor of how much sugar came out of the taps over those 17 years," says Rapp. "That tells us there is something else at play."
For several years, Rapp and Crone have been studying "mast" seeding events—years when trees collectively produce far more seeds than usual—at the Harvard Forest in Massachusetts. In sugar maples, mast seeding tends to occur every 2 to 5 years.
Recent mast seeding events occurred in Vermont in 2000, 2006, and 2011. Rapp's research shows that in Vermont, syrup production declined following every mast seed year.
Maple syrup production declines after big seed year
A heavy sugar maple seed crop. Credit: Josh Rapp
"Both seeds and sugar are made from carbohydrates stored in trees," explains Crone. "When a tree produces a lot of seeds one summer, then the next spring, the carbohydrate bank account is low for making sugar. It's a matter of budgeting resources."
Looking ahead to next year's harvest, Rapp notes: "At the Harvard Forest, and likely throughout the northeast, the seed crop was small this year, suggesting the 2015 maple syrup harvest should be a good one."
Rapp explains weather's role in these predictions: "The best way to predict syrup production is actually a combination of factors: proportion of trees with seeds, minimum and maximum March temperatures, and maximum April temperature. Those factors together explained 79% of the variation in syrup production in Vermont from 1998 to 2014."
Because seeds develop a full six months before syrup harvest, Rapp hopes this study can help syrup producers plan ahead. "Maple syrup is a complicated natural resource," he says. "Hopefully this research can give producers a window into the upcoming season."
"The idea of looking at the costs of seed production came from very abstract models developed by mathematicians in Japan," adds Crone. "One of the purposes of academic science is to come up with general insights that help us see applied problems in new ways. This is a good example of that kind of insight."
Explore further: Syrup makers go high tech with wireless monitoring
More information: JRapp and ECrone. 2014. Maple syrup production declines following masting. Forest Ecology and Management 335(1): 249-254. Available online 27 October 2014. DOI: 10.1016/j.foreco.2014.09.041
Journal reference: Forest Ecology and Management

[stoneslabs]

that is an interesting read... for me, 2014 seemed to be a low producing year and, yes, 2013 was an unusually high seed year. there may be something to this study!

[Loch Muller]

Very interesting and something I never really considered before. Has anyone read the original article in the Journal of Forest Ecology and Management? I'd like to see their methods and how they analyzed their data, but unfourntanely no longer have acess to that journal though the college I went to. I'll probably keep tinkering with my setup, tapping and boiling regardless of how many seeds were on the trees last year. It is good to understand what makes it all work though. Learning new things and applying them to my operation to make it work better is what makes sugaring so much fun for me.

[Homestead Maple]

I can remember old timers saying the same thing 30+ years a go. They didn't have time to do research but they always paid attention from year to year what was going on with the weather and their sugar orchard.

[lew]

I've noticed over the course of my sugaring career, that years following a heavy seed crop we would have a lower average sugar content. But what has really made for a good year or a bad year was the weather dealt to us during the sugaring season. I can remember an extremely heavy seed crop in the early '90s that the following year made the woods look like we had a carpet of maple seedlings. Also the following year we had perfect weather conditions for sugaring. Made syrup from mid February to mid April, an 8 week season. With gravity tubing we made 1300 gallons of syrup on 2700 taps. It was a cool, wet, nasty (weather wise)season. But perfect for us.
Vacuum has taken a lot of the weather out of the equation though I suppose. In my opinion, vacuum helps keep the tap hole cleaner helping with production beyond the vacuum effect itself. In the days when "the pill" was available, it did the same thing ( we used them during the season mentioned earlier). It kept the hole clean so you could wait for a freeze to occur, sometimes 2 weeks after the last freeze in late March and still get a great run without vacuum.
My writing is rambling, but my thoughts are that without vacuum, weather is the almighty influence. If the trees are thawed out Vacuum is the equalizer, taking many of the ups and downs out of production. Take this past year for instance. We had a 10 day season. Guys without vacuum in our area had a dismal season. Many with less than a pint per tap. Vacuum producers were anywhere from .3 to .5 gallons per tap. Our sugar content was lower in 2014 than 2013, but we still made .3 gpt. Only quit because we couldn't get the syrup through the press. Still lots of sap with the vacuum. So I guess what I'm trying to say is that you can have all the sugar in the world in the trees, but if it doesn't thaw out, you can't get to it, thus no syrup. If we had normal sugaring weather last year, just think how much syrup could have been made. It wouldn't matter how many seeds were put out the previous year, you would have had a LOT of sap to boil for the season.

Just my rambling thoughts. I think the weather has the most to do with the sap production for the year and the seed crop has more to do with the amount of sugar in that sap.

[BreezyHill]

I have to agree with lew. Last season as an average of all taps was very poor for high vacuum. Put with a glass manifold and releaser you can see how each line is running all the time at a glance. Our main bush is east facing and we had breezy conditions most all season. This shut down the trees on the windward side of the bush with the trees on the next mains doing fair and those that were protected did amazing. When we pulled taps and washed lines on
April 23 we had trees that were all done will others were running like crazy; but with the temps in the 60-70 range the sap was not worth working with by mid afternoon.

Weather is the big gamble when it comes to any sort of farming....and its legal in all states.

[lew]

Be careful what you say Breezyhill. You live in a "Nanny state". If they find out we're gambling, they'll shut us down.

[BreezyHill]

Aint that the truth!!! Jusst wait til Cumo puts the safe act 2 thru....we have to register all our rifles and pay an annual renewal....are you kidding me????

I think he will need to stay down state to be out of range of the patriots.

Why is it the lunatics come to New York???

Sorry was reading a email from an NRA friend earlier.