Maple Production Northeast

Maple sugaring has been part of the Northeast's identity throughout its history as it was a practice passed along by the natives of the region.

  • Maple products are now an economic staple as it was a one hundred and forty one million dollar industry in the Unites States in 2017 and continues to grow as technological advances push producers to new heights though total yield numbers are down five percent from the previous year (United States maple syrup production, 2018). Although, the Northeast of the United States has begun to fall behind in production to southwest Canada as our changing climate makes parts of the southern northeast less viable for producers (Perkins, 2017). 

Syrup production shown in gallons 

Northeast Climate Science Center 

Tree Health


Tree health is the first area of vulnerability when considering climate change and its impact on maple sugar in the northeast United States. The species of tree that is predominantly used for sugaring is the sugar maple (acer saccharum). The sugar maple is an economic staple not only for for its ability to yield sap but as well as timber because of its strength. 

Acid Rain 

  • Land within the northeast is generally loamy, well-drained calcium rich soil that has a Ph balance suitable for sugar maples to grow and reproduce. Though in the recent past acid rain has changed the make up of the soil creating a nutrient imbalance. Acid rain is the byproduct of greenhouse gas emissions that fall back down to earth generally from industrial coal fired power plants of the Midwest. The acid rain depletes the amount of calcium in the soil increasing the acidity levels and making the soil less fertile (Ramanujan, 2006).


  • Sugar maples are also sensitive to defoliation by pests, specifically the Forest Tent caterpillar in times of drought. Although native to the northeast region, while in a time of drought these caterpillars are far more destructive to the sugar maples. In 2017 alone 60,000 acres of defoliation occurred as drought like conditions were frequent during the growing season causing outbreaks (Thompson, 2018).

Sap Quantity and Sugar Content

Hydrometer measuring density of maple syrup (Brixx) 


Sap quantity and sugar content are other vulnerabilities, which have a strong correlation to each other. Much research has found that above average or higher temperatures during the growing season causes a reduction of sugar content seen that following tapping season. One study conducted at the University of Massachusetts collected data from six different sugar bush plots from Quebec to Southwest Virginia. The regions with the cooler mean July temperature had higher sugar content within the sap (Stinson, 2018). As could be expected, these locations were situated the furthest north.  Higher sap content is essential for having a profitable sugaring season because it means your overall efficiency is higher.  In instances where sugar content is low, the ratio of sap that has to be boiled increases. Even a one percent difference in the percent sugar could mean a bad year for a producer.

ACERnet – Acer Climate and SocioEcological Research Network

Northern Migration of the Sugar Maple


An area of concern that gets a lot of attention is the migration north of the species range, which is and will continue to significantly diminish the availability of trees that can be used for maple sugar production. The range of a tree species is generally where a specific species can be found during its lifetime due to the regions temperature, soil and precipitation needs. If temperatures continue to rise in the region the southern edge of the range for sugar maples will continue to shift north. This shift happens because the species is stressed and germination rates of new seedlings on the southern edge are diminishing while they continue to thrive in northern edge of the range where the latitude is higher. Research done by the United States Forest Service found that tree migration might continue and accelerate to nearly 100 km per century for northern species including the sugar maple (Woodall, 2010).

Projected forest make up in 2070 


The sugar maple requires a well-drained, deep, fertile sandy loam soil composition, which does not exist as you go further north and hit the boreal forest north of the United States (Reynolds, 2016). The soil in this regions is highly acidic, and is not deep enough due to the precense of perma frost, meaning the sugar maple will soon run out of suitable land that accommodates its ecological niche. Also the growing season is far too short for the survival of deciduous trees such as the sugar maple (Nelson, 2013).  A study done in the Adirondack region on sugar maple growth trends found that growth trends have been negative since the 1970s and have intensified from the 1990s onward. In this particular study there were 242 trees in the sample and nearly 140 had an observed negative growth trend (Bishop, 2015)

Tapping Season Shifts

Lorraine C Manley 


  • On average the tapping season starts eight days earlier and ends eleven days earlier than just fifty years ago (Perkins, 2017).
  • The tapping season, known as the period of time between winter and early spring where there is a consistent freeze/ thaw cycle. This cycle is what generates sap flow due to pressure changes inside the tree pushing the sap out. This period of time must contain daytime temperatures hovering around or above 40F and nighttime temperatures that at least reach below freezing or 32F.
  • It is a common practice nowadays to tap your trees early in February in anticipation for earlier warmer spring temperatures that are now expected as the norm.

Climate Change Adaptation


Technological Adaptation:

  • Vacuum collection lines

Adding vacuum to collection lines through the use of a pump allows for increase yield regardless of fluctuations in the freeze/ thaw cycles caused by climate change. Producers are able to maximize yield using up to twenty five PSI in the lines to draw the sap out of the sugar maples. 

  • Reverse Osmosis

Reverse Osmosis involves using a membrane to separate a majority of the water from the sugar before the boiling process. This speeds up the evaporation process immensely and allows producers to increase efficiency.  

  • New higher quality tree taps 

A new spout has been produced by the University of Vermont's Proctor Maple Research Center and claims up to a ninety percent increase in production. The spout includes a one way valve allowing no sap to run back into the tree during pressure fluctuations which could include bacteria and stress the maple tree and decrease yield. The tap has such high hopes that the creators believe it will mitigate the effects of climate change on the industry (Science X).  


  • Calcium fertilization of Sugar Maple stands  

A study conducted by the University of New Hampshire has found that the use of calcium fertilization improves sugar maple crown condition and seedling density (Juice). 


Proactive Sugaring Techniques: 

  • Tapping a larger number of trees 
  • Tapping trees earlier in the season 




Although producers have been able to mitigate the impacts of our changing climate temporarily by using the latest technology and proactive farming techniques there will come a time when this already labor intensive industry will not be practical. A statement from climate central reveals that shifts in ecological patterns after 2100 could mean the end of the industry, due to the sheer loss of the sugar maple species (Perkins, 2017). Many view climate change through a species such as the polar bear with very little personal connection, but I am just as concerned about a species that is right in my backyard. Hopefully the importance of the sugar maple and the industry that has been built around it and its connection to the Northeast's identity can spark education and awareness to shift the scenario that we as humans fall into.


About myself: 

I grew up on a eighth generation family farm near Burlington, Vermont. Although we are no longer a dairy farm we continue to find ways to keep our farm and identity alive including the production of maple syrup with our 5000 vacuum fed taps. 




Woodall, Christopher W.  “Study Suggests Tree Ranges Are Already Shifting Due to Climate Change.” w US FOREST SERVICE NORTHERN RESEARCH STATION, US Forest Service, 2010,

Perkins, Timothy D. “Maple Syrup Season and Climate Change.” Climate Central, University of Vermont Proctor Maple Research Center, 22 Feb. 2017,

Ramanujan, Krishna, and Ted Feldpausch. “Decades of Acid Rain Is Causing Loss of Valuable Northeast Sugar Maples, Cornell Researchers Warn.” When Opting for Happiness or Income, Many Go for the Cash, Cornell Chronicle, 2006,

Staff, Science X. “Innovative Spout Will Increase Maple Production up to 90 Percent.”,, 18 Aug. 2009,

Stephanie M. Juice, 1 Timothy J. Fahey, 1,6 Thomas G. Siccama, 2 Charles T. Driscoll, 3 Ellen G. Denny, 2 Christopher Eagar, 4 Natalie L. Cleavitt, 1 Rakesh Minocha, 4 And Andrew D. Richardson. “Response Of Sugar Maple To Calcium Addition To Northern Hardwood Forest.” Ecological Society Of America , 2006, Www.Forest.Sr.Unh.Edu/Richardson/Juice06.Pdf.

Stinson, Kristina. Climate Effects on the Culture and Ecology of Sugar Maple. 2018, /Users/owenmanley/Downloads/Stinson%20Final%20Report%20-%20Sugar%20Maple%20Project%20Final.pdf.

Thompson, Leon. “Forest Tent Caterpillars Back on the Crawl in Vermont.” The Maple News | Maple Industry Trade Publication, 2018,