As I reflect on this past weekend's 60+ degree days, it's hard to imagine climate change not affecting maple sugaring since it is so dependent on weather. I am often asked why we tap our maple trees in the winter; wouldn't it be more enjoyable hiking out to check the buckets and tap the trees when it is 60 degrees? It most definitely would be; however, it is the alternating freezing and thawing cycle that occurs in late winter that controls the sap flow.
Studies conducted by scientists at the Proctor Maple Research Center at the University of Vermont have found the maple sugaring season in northern New England starts approximately 8.3 days earlier and ends 11.6 days earlier than it did 50 years ago. They have also found that the transition from winter to spring to be much shorter, and that time represents almost 10% of the sugaring season. While we tap our trees in late January/early February here at the Arboretum, traditionally sugar makers waited until the first of March to tap their trees for fear of earlier tap holes "drying out" before the heavy sap runs later in the season. The problem with waiting that long, however, is they miss the earlier sap runs that are becoming more common with the warmer winters.
According to Timothy Perkins, Director of the Proctor Maple Research Center, technological advances in collection techniques have so far outpaced losses in sap flow, but he is unsure of the long-term impact on the industry. While vacuum tubing can help combat some of the affects of climate change, warmer temperatures will continue to have a negative effect. Back in 2012, an unusually warm spell in January kick started the sugaring season much earlier than normal, and many sugar makers missed the early sap flows. Then, wildly fluctuating temperatures in March brought an early end to the season. Producers throughout the region saw a 27% drop in production compared to previous years. Today, sugar makers are beginning to tap earlier than in years past ensuring to capture the early sap flows which are becoming more the norm than the exception.
Scientists are also concerned that climate change will affect where and how maple trees grow – a warmer, drier climate will change the make-up of the forest with maple and birch tree communities migrating further north and being replaced with oak/pine tree forests like what is found here. Will there be more disease, will less snow pact and warmer temperatures stunt the growth of sugar maples? No one knows for certain. The bottom line is, as temperatures continue to rise, there will be affects on the maple sugaring industry, however it appears as though sugar makers are not tossing in the towel just yet and are working to stay one step ahead to minimize the impacts.