The whir of drills and the tap of hammers will soon be resonating from sugarbushes. Clouds of roiling steam and the first waft of fresh syrup won’t be far behind. As the 2008 season kicks off, how are our sugar maples doing? Are the trees healthy these days?
The answer is yes.
How do we know? All 9.3 million acres of forest in New Hampshire and Vermont are checked each year as part of a forest health monitoring partnership between the U.S. Forest Service and the forestry departments in each state. Nearly all of the work is done from low-flying aircraft, where visual observation is combined with camera work to keep track of things like insect infestations and crown die-back. These overflights are combined with trips on foot into the woods to examine specific trees, including maples, to see how they are faring from one year to the next.
The word in 2008 is pretty good.
The past two growing seasons have both featured a fair bit of rainfall, evenly spaced across the months. Water is a key ingredient in photosynthesis, and sugar maples now have two solid seasons in a row of making and storing sugar. The tail end of last summer became quite droughty across much of the region, but a late drought is less of a problem than an early drought, since the trees make most of their sugar in the earlier part of the season when the leaves are young and fresh.
When sugar maples have ample supplies of moisture and stored energy, it’s like money in the bank; they have the reserves to weather hard times, which may include insect attack or disease outbreak or even broken limbs from ice storms or high winds. Right now, our sugar maples have more reserves on hand than they have in recent years.
Adding to the positive picture is the apparent end of the recent forest tent caterpillar outbreak. These caterpillars, which build silken mats on branches high in the canopy (unlike their Eastern tent caterpillar cousins, which spin their webs in apples and cherries in sunny areas), go through cycles of population booms and busts. The most recent boom appears to have peaked in 2006.
When populations of forest tent caterpillars are high, the insects defoliate tens of thousands of acres of sugar maple, causing the trees to expend those precious reserves to either leaf out for a second time or hang on until the following spring with enough energy to try again. Those that were hard hit in 2006 were, by and large, able to leaf out again in 2007 to take advantage of the good growing season.
In Vermont, where 2,000 individual sugar maples were examined in 2007, more than 90 percent were considered healthy.
Not that everything is positive for the sugar maple. A caterpillar called the saddled prominent, which enjoys maple leaves among others, appears to be entering into one of its cyclical population booms – the first in several decades. The southern Green Mountains and southern White Mountains have seen the highest numbers so far.
Sugar maple is also being adversely affected by acid rain. The acidity interferes with the trees’ uptake of calcium, critical to maintaining winter hardiness and dormancy. The problem is most acute in southwestern Vermont, which is closest to the midwestern power plants that generate much of the acid-rain causing pollution, and at the higher elevations of the Greens and Whites, where soil calcium levels are naturally lower.
Deer also are taking a toll on sugarbushes: the herd, which is quite large in many areas, browses on and kills young maple seedlings when food is scarce in the winter. This is an area where many sugar makers feel conflicted: as nice as it is to see new growth in the sugarbush each spring, it’s also quite a thrill to see a buck in the sugarbush each fall.
But overall, the start of 2008 is looking better than average for sugar maples across the twin states. In Vermont, where the sugar maple is the most common tree species in the forest and where the annual syrup crop is the highest in the nation, the Department of Forests, Parks and Recreation has given sugar makers the green light to resume normal tapping procedures after several years of caution during the tent caterpillar outbreak.
Besides healthy trees, sugar makers have a healthy marketplace to look forward to in 2008. A substantial backlog of Quebec syrup has been sold off over the past year, so the syrup supply is expected to be tight this year, boosting prices. The trees are in good shape, the market is up…would it be pushing things too far to hope for some favorable weather?