The groundhog predicted an early spring to no one’s surprise given the dearth of snow this winter. Warmer temperatures meant many people in the region did not see a white Christmas and some larger maple producers tapped trees in December. Climate change is impacting the maple industry and University of Vermont Extension Maple Specialist Mark Isselhardt tells WAMC North Country Bureau Chief Pat Bradley producers are trying to adapt to the changes:
1 The number one thing that we see in maple is the season where the densest concentration of days with ideal sugaring weather, the weather that stimulates positive sap pressure, we see that period of time moving earlier. And we’re also seeing the ending coming earlier and the overall duration being compressed. It’s definitely been happening for at least 40 years, maybe more. The shifts aren’t huge but it’s really important to recognize that while that’s been happening, we’ve actually seen an increase in the amount of sap harvested per tap go up. And that’s largely a reflection of more and more sugarmakers using modern sap collection practices with tubing and vacuum as well as managing those systems for limiting leaks and keeping sanitation to a reasonable level. All those things contribute to increasing yields.
With the changes that we’re seeing due to climate change, as you mentioned the compressed season but also the use of technology to increase the yield, is all of that damaging or affecting the maples in any way?
That’s a great question. It’s something that we ask here at the University of Vermont Proctor Research Center as well as other institutions that look at maple. It’s a difficult question to answer however because you have a perennial plant that lives for a very long time. Sugar maples specifically can live to be 250 – 300 years old. And although tapping is a stress, the observations we’ve made don’t suggest that it’s an acute stress, more akin to a chronic stress. And we have about ten years worth of work, it hasn’t been published yet, that looks at what are the effects of modern high levels of sap extraction compared to more traditional levels as well as a no tapping control.
Mark Isselhardt, how are maple producers trying to adjust to meet some of the challenges they’re encountering because of some of these climate changes on the trees?
Producers are definitely concerned about issues related to climate change. It’s not just temperature, but what those temperatures mean for giving a leg up for perhaps invasive organisms, plants and other organisms that would crowd out native vegetation including maples that are trying to regenerate. So there’s real concern there. We’ve seen over the last few decades a really increase in the number of certified organic producers. In Vermont I would say conservatively two-thirds of the crop are made at operations that are certified organic. And while there isn’t a huge amount that has to happen on the producer side they do need to follow a forest management plan and almost all those certifiers require some level of species diversity in the woods. And that really does help especially in terms of pests, either invasive pests or native defoliators, having some diversity in the woods can really help mitigate some of that damage when those defoliators, those populations, ramp up. There’s also an acknowledgement that doing careful active management to maintain healthy trees it’s going to pay off both in terms of sap production but also perhaps lessening the impact of natural disturbances that we associate with some of the issues of climate change, you know high wind events, or some of the flashy flooding that tends to be a little bit more common. A healthy tree is going to be more resilient to that and a forest that retains more woody debris on the ground rather than getting it all picked up, it turns out that sugarbushes or forests that have more complexity tend to do better in terms of keeping water from running off and speeding up and causing issues downstream. So all those things are becoming more present for sugarmakers where in the past it was really how do you grow big trees that are widely spaced since back then the technology was really buckets and if you can put your energy into fewer individual trees that you have to go to each day it makes sense from a production standpoint.
What do you think the maple industry in Vermont might look like by the end of the century?
Well, I’m still optimistic. I think that there’s very little chance that we are going to see a massive change in the species composition in that period of time. In Vermont we have one in four trees are maples. It’s not true in every location that makes maple syrup but. The state of New York has a huge number of maples. And the fact that most producers, virtually all producers rely on natural regeneration and do so successfully, means that there are multiple generations waiting to fill in the maybe gaps that would be produced by trees that are dropping out of the canopy. So I don’t see large wholesale changes coming in the composition at least in that period of time. Longer periods, yeah it’s a real concern.
