Future of the Forest
Part B: Maple Syrup and Climate Change
Recall the 300-year old maple tree in Vermont, described in Lab 1. How do you think that tree, and others like it, will respond to changing climate? Maple syrup, a sugary sweet food product derived from the maple sugar (Acer sacchurum) tree, is an important agricultural commodity in the northeastern and mid-western United States. How will climate change impact the production of this commodity? To answer this question, researchers, farmers, and citizens have carefully monitored the changes in the sap flow every spring for many years.
In this lab, you will view graphs, diagrams, and video clips describing the changes that have been observed by farmers in Wisconsin and Vermont. You will view scientific articles and an interactive that display the potential changes in syrup production.
The maple syrup - climate connection
Learn more about the sugaring process and the climate by reviewing this 3-minute video about a farming family's experiences sugaring in central WisconsinSugaring Wisconsin.
- Why does the sap run in the spring?The days are warm (above freezing) and the nights are cold, below freezing. The alternating of warm and cold temperatures triggers the tree to start moving the winter-stored sap from the roots up the trees.
- How do farmers turn sap into sugar?They collect it and then boil it in evaporators.
- What is changing the flow of the sap in Wisconsin?There are fewer days where the temperatures fall in the right range of cold (below freezing) and warm.
As the climate changes, so do the winter and springtime temperatures. Scientists at Cornell University, near Ithaca, New York, have studied the changes in the onset and duration of the maple sugar season. First, read this short synopsis of their findings: Maple Sap will Flow a Month Earlier.
Next, use the sap flow interactive, below, to explore how the sap flow days may change in the future as the climate of New England changes. The Historic Sap Flow Window is the time period in which the maple sugar season traditionally has taken place in New England. To get a sense of the changes predicted for the maple sugar industry, in the coming century, try the following: select a city and begin with the Present temperature, then change scenarios to see how climate change may shift the sap flow "window" earlier and earlier in the year.
- Click on a city. Note: Ithaca, N.Y. is the default city.
- Choose an emissions scenario. Present, High, or Low. The map will depict possible temperature patterns given the scenario.
- Observe the calendar bar above the image to see how the start date, and number of days of sugaring season (sap flow days) change with modeled climate changes.
- Observe the average winter temperature in the regionpictured on the thermometer to the right of the map.
- When you are done exploring, use the interactive to answer the Stop and Think questions, below.
Stop and Think
- Which city will see the most dramatic change (greatest increase) in temperature in RCP 8.5 (high) emissions scenario?
- Which scenario produces the greatest change in temperature?
- Which city, and region, will see the most significant change in the sap flow start date?
- According to the article, Maple Sap will Flow a Month Earlier, linked above; how will climate change affect the maple syrup industry?
- The Historic Sap Flow Window is the time period in which the maple sugar season traditionally has taken place in New England. If farmers were to continue to use this time period for sugaring, what would happen to their production?
Read more about the impacts of global warming on New England on this page seasons of change. Watch the video clip of a New Hampshire farmer describing his observations. (Click the link entitled: "Maple Sugar Production" on the lower-right corner of the seasons of change page to access the video.)
Some farmers in Vermont, and other regions, have turned to technology in order to increase the production of their maple syrup. While the innovations have increased the amount of sap they can draw from the trees, the concern for the sustainability of the industry in Vermont remains. Read more about the new methods of collection being utilized in this old industry in this New York Times article: High-Tech Means of Production Belies the Nostalgic Image of Maple Syrup. A slideshow accompanies the article.
DiscussWhat observations of climate change do the farmers in Wisconsin and New England have in common? How has the spring run of maple sugar changed during their years of work with the maple tree?
Do you have relatives or friends that work in the out-of-doors or with plants? What can plants tell us about the weather and climate that we might not notice without them? What are the impacts of climate change on plants in your region?