Climate Change and Maple Sugaring

September 25, 2017

OK. Enough bucolic wandering through the forest to identify the best trees for sugaring. Enough feel-good homemade maple syrup peaches. It’s Monday morning. Grab a cup of coffee. Let’s talk about climate change like we said we would.

No, it’s OK! This is NOT going to make you feel like crawling under a rock. It’s more likely to make you want to take a walk at lunch or cause you to rubberneck on your commute home to evaluate species diversity, look for snags and riparian buffers and wonder about the slope and aspect of your neighborhood’s topography.

(What!?)

Hang in there. I didn’t know about any of these things either, until I accepted the gracious invitation of the Orange County Maple Sugar Makers Association to show off the Sapling Evaporator at their annual meeting last January. There I met Nancy Patch, County Forester for Franklin and Grand Isle Counties here in Vermont. Nancy gave a great keynote speech about climate change and maple sugaring over a (very yummy) pot luck lunch featuring this amazing shortcake slathered in maple cream:

Maple biscuits

These distracting maple shortcakes have nothing to do with climate change.

Oops. Lost my way, there. In addition to remembering the wonderful food, I took away some interesting information about how climate change will affect maple sugaring and some important tips about caring for my sugar woods from Nancy’s talk. I interviewed Nancy recently to refresh my recollection, and this is how it went:

Kate: One of the things that I recall from your talk, and one of the things that I’ve told my readers, is that Red Maple trees are going to fare better than Sugar Maple as the climate changes. Which means that backyard sugar makers of the future will still be able to sugar, but might have to work a little harder. Now that I’ve read Increasing Forest Resiliency for an Uncertain Future, however, I’m not sure. Will you explain?

Nancy: Sure. The Sugar Maple is a “Goldilocks” tree. Sugar Maples require soils rich in calcium and magnesium with the right moisture content, enough snow cover to protect its sensitive roots from freezing in the winter, and particular temperatures in order to regenerate. This is where climate change comes in.

The Red Maple is a genetically diverse tree that can thrive in a wider range of situations and has a much wider geographical range. The Red Maple can thrive in acidic soil or on ledge, in swamps and can handle drought conditions, for example.

Neither the Sugar Maple nor the northern hardwood forest in which it grows are going to disappear in the foreseeable future, but climate change – including warming temperatures, shrinking snow cover, and the increase in the incidence and severity of ice storms – will put stress on the Sugar Maple’s ability to thrive and reproduce outside of areas with optimal soil and moisture content, causing it to be out-competed by other species, including the Red Maple.

Kate: So climate change is not going to damage existing trees as much as it is going to make it hard for them to reproduce?

Nancy: Right. Reproduce and compete.

Kate: OK, so how will climate change affect the business of sugar making?

Nancy: It has already. Sugar making is a responsive industry that has long dealt with the reality of climate change. Already, professional sugar makers tap earlier [rising temperatures mean earlier springs] and use tubing systems that keep the wound in the tree open to accommodate the uncertainty of the season.

Kate: How will climate change affect the business of sugar making in the future?

Nancy: We really don’t know. It is always important when talking about climate change to note that we really don’t know what is going to happen. We don’t completely understand how trees adapt. And adaptation does not necessarily take forever. Another thing we don’t understand about trees is how they communicate with each other.  So keeping the forest’s options open is the best we can do, and this means species diversity [number and abundance of species in the woods] and structural diversity [diversity of tree age and size, and existence of openings in the canopy, standing dead and logs on the ground] in the woods.

Kate: How do we keep a forest’s options open for sugaring?

Nancy: One of the things I have been pushing people to do is to keep and cultivate Sugar Maples in places where the conditions are really optimal – places where slope [the pitch of the land] or aspect [the compass direction that a slope faces] keep temperatures down, and places with mineral-rich soil and the right moisture content. Beyond that, it comes down to protecting or creating diversification among trees and other species, and ensuring your sugar woods has trees of many different ages so that when disturbance occurs there is a replacement forest.

Kate: What can backyard sugar makers do to make sure that future generations can continue to enjoy the hobby they love?

Nancy: The first thing I would tell a backyard sugar maker to do is to remove invasive species annually by cutting, pulling or burning them (when snow is on the ground and it is safe to do so). The big three in sugaring country are buckthorn, honeysuckle and barberry. This will go a long way in protecting the forest habitat, which increases forest resiliency, which means healthy sugar woods. Big producers may have too much land to completely eradicate invasive species, but someone with a ten-acre plot, for example, can handle it, and even work with their neighbors to increase the impact of their work.

The second thing I would tell them to do is to look at the diversity of trees in the 250 acre area that includes and surrounds their property, and try to figure out how close it is to containing an ideal suite of tree species for their type of woods. A county forester or extension service may be helpful there. If there’s diversity already, do what you can on your own land to maintain it. If diversity does not exist, you can plant trees or expand on what you have already by, for example, giving a mature oak some space to thrive and reproduce by thinning around it.

Finally, I would tell them to protect or create the potential for diversity for other species, including wildlife, by leaving standing dead trees [called “snags”], leaving dead logs on the ground, and, where bodies of water exist, ensuring that riparian buffers [forested area providing shade] are in place.

See? That wasn’t so bad! Now get out there and take a walk, snap some pictures, and tell us what you find. I’ll be sure to do the same, and report back. Until then, I’ll be looking for that maple shortcake recipe to share . . .