Author Douglas Whynott spent a great deal of time two and three years ago with big commercial syrup producers in New England, the heart of American maple syrup production, including one New Hampshire family that has become over several generations perhaps the biggest in the country.

The Bascoms have gone from collecting sap from wooden taps and buckets hung on trees in a modest "sugarbush" to processing and marketing syrup from more than 68,000 taps on 800 acres of woods. The sap used to be collected in the spring by family members working some years on snowshoes, trudging from tree to tree and loading the harvest onto ox-drawn wagons. Now the sap flows along 332 miles of tubing. Not as romantic, maybe, but certainly more efficient.

Yes, Minnesota has a maple syrup industry, too. The Minnesota Maple Syrup Producers Association (www.mnmaple.org) claims more than 100 commercial and hobbyist members, and sugaring continues to be an important cultural activity for its original practitioners, American Indians. But production here is dwarfed by the output in New England and even more by the industry in Quebec, where producers in an OPEC-like cartel called the Federation command a "global strategic reserve" to guard against price spikes, crop failures and competitive threats.

"The Sugar Season" tells the story of the annual sap run, when the cycle of warming daytime temperatures and nighttime freezes triggers the movement of sap in the sugar maples. Despite growth and technological advances, it remains such an elemental story — of trees and their biology, of children working alongside grandparents, of steam and sparks in the sugar house in the overnight boiling down of the sap. It is, like most agricultural pursuits, a life of risk and hard work. But much of that work is done in the aromatic woods, with stunning mountain-to-valley views.

Whynott gets a bit overly detailed describing the financing, processing and marketing of all that sweetness, but he compensates with lyrical history, geography and insights into family life centered around a demanding business. The Bascoms may have a cooler capable of storing 8 million pounds of syrup, more than a third of the national crop. But they also open the gates at season's end so visitors can sit at tables with them and learn about sugaring while sampling pancakes drenched with pure maple syrup, maple candy and "sugar on snow," warm syrup dropped on a plate of clean snow, where it cools and congeals and becomes a fragrant and chewy goodie called "leather aprons."

Whynott also found among the maple sugar producers widespread concern about global warming. Veteran producers are tapping their trees weeks earlier than they used to, and scientists have warned that climate change could wipe out the sugar maple in New England.

"Maybe the maple syrup industry can speak for the rest of the country, to the rest of the country," Whynott writes, "for it is a bellwether, this earliest of agricultural traditions, the first to be taught to settlers by Native Americans, this pursuit that relies on sensitive fluctuations in temperature, as the sun advances north and the trees freeze by night."

Chuck Haga is a writer in Grand Forks, N.D.