Tag Archives: sap flow

Maple syrup mechanics: xylem, sap flow, and sugar content


Proctor maple research field station, Underhill, VT

Proctor maple research field station, Underhill, VT


Tapping sugar maple to collect sap


Maple syrup might be the oldest agricultural product in North America. Early 17th-century written records from Europeans exploring North America describe Native American use of sugar maple sap.  We of course can’t know how Native Americans discovered sugar maple sap, but it may have been by sampling a “sapsicle,” icicles made from frozen maple sap that forms at the end of a broken twig.  The evaporation of water during ice crystallization partially concentrates the sugar in the sap, making the sapsicle particularly sweet.  To understand how that sap got to the end of the twig in the dead of winter and why it’s so sweet, we need some basics about plant vasculature and carbohydrate storage and must figure out what makes maples so special. Continue reading