With 84 percent of our state covered in forests, New Hampshire is the second-most forested state in the nation after Maine, according to the state Division of Forests and Lands. That’s about 4.8 million acres of land, with an estimated 4.2 billion live trees — and much of it goes regularly unexplored.
The state’s greenery and forest types vary from one place to the next. Some forests even have hidden treasures, from rare plant species to ancient trees.
New Hampshire’s forests are broken down into five major categories: Appalachian oak-pine, hemlock-beech-oak-pine (or HBOP), northern hardwood conifer, lowland spruce-fir and high-elevation spruce-fir.
According to Gabe Roxby, a field forester with the New Hampshire Forest Society, Appalachian oak-pine forests are only found in southern parts of the state and are relatively less common than the other forest types.
“New Hampshire is kind of at the northern edge of the Appalachian oak-pine forest type,” Roxby said.
It includes species like red oak, white oak, black oak, hickory and pine.
The HBOP forest type is the most common in the state and can be found in large swaths from the Lakes Region down.
Further north and in parts along the west of the state, you’ll find a higher concentration of the northern hardwood forests. These include the trees with the brightest color leaves during the fall foliage season, such as beech, sugar maple, yellow birch and other birches and maples.
Spruce-fir forests thrive in colder temperatures so they’re found in the northernmost parts of the state and at high elevations like in the White Mountains. For that reason, these forest types are divided into lowland and high-elevation categories. They include mostly red spruce and balsam fir. While these are mostly up north, one notable exception is the top of Mount Monadnock, according to Roxby.
Compared to other nearby states, New Hampshire’s soil is more acidic. Vermont soil, by contrast, is more balanced due to calcium released by more limestone in the bedrock, which makes it better for vegetation. But there are some places in New Hampshire that have richer, moister soils that provide a habitat for more herbaceous plant life. These are called “rich mesic forests” and they include places like Pawtuckaway State Park, Coleman State Park and Cape Horn State Forest (see page 15).
Different forests are also in varying stages of growth. Old growth forests, mature forests and transitional young forests known as “early successional” forests all exist in the state.
Right now, the state’s forests are in a period of significant regrowth and most forests are neither very young nor very old.
“A lot of the forests in our state have been cut over and cleared. Almost all of them. There’s very little old growth left in the state,” Roxby said.
While most trees are relatively younger, aged around 100 years on average, there are some notable exceptions. A few years ago, state researchers discovered the oldest tree found anywhere in eastern North America. It was a black gum tree (also known as a tupelo) aged about 700 years old. Pete Bowman, wildlife biologist at the New Hampshire Natural Heritage Bureau, said the tree is located with a few other ancient black gums in a swampy basin on private land in Deerfield.
The age and composition of a forest can affect what kinds of animals might take up residence in a forest. For example, some birds like Grey Jays or Spruce Grouse require spruce-fir forests and can’t be found outside of one. Lots of mammals require significant tree cover for their habitats, so as forests grow back, the state sees an increase in deer, beaver and bobcats. Other species like porcupine and turkey have been doing well as a result of a number of factors from conservation efforts to shifts in predator populations.
Canine species like gray fox, coyote and fisher have reached such high population numbers they are now being affected by natural population controls such as canine distemper.
But while some species thrive in mature forests, others prefer young transitional forests.
Forest historian Tom Wessels of Antioch University of New England said when abandoned farms in the state gave way to rebounding forests, it provided ideal habitat for species like New England cottontail, grassland bird species and warblers that need small, “shrubby” trees.
“Now, we’re seeing them really decreasing because we don’t have those those really early successional ecosystems much anymore,” Wessels said.
Making way for sheep
The current formation, age and composition of the state’s forests was largely the result of human intervention.
According to Wessels, there were two significant historical developments that shaped our forests, the ripple effects of which are still felt today.
The first big wave of deforestation in New Hampshire, and much of central New England, was to make room for sheep pastures, according to Wessels. But for a strange turn of history, this might have never happened.
Farmers in New England had some sheep already, but they didn’t produce very good quality wool. That changed when a diplomat from Vermont named William Jarvis performed an act of international theft.
In the early 1800s, Spain was exporting high quality wool from a special breed of sheep called merino sheep. They grow long hair at faster rates than other breeds and their wool could be woven into higher-quality garments known for being more water resistant and itch-free. Wessels said that while Spain sold the wool, they had an embargo on the sheep itself, hoping to hold onto their merino monopoly.
While serving as consul in Portugal around 1810, Jarvis took advantage of Napoleon’s invasion into Spain and smuggled 4,000 merino sheep out of the country through Portugal, according to Wessels. He even gave a few to his buddy Thomas Jefferson.
Around the same time, after the War of 1812, new tariffs on wool imports protected local wool producers from international competition and by 1814 the power loom was invented, allowing for mass industrial production.
Merino sheep were a sure money-maker for New Hampshire farmers. The only catch was land; sheep need a lot of it. The obvious solution was to clear out huge areas of forest. Wessels said by the middle 1800s, about 80 percent of the state’s forests were cut down, the bulk of them for sheep pasturage.
“It changes the landscape because it’s sort of the first large-scale market farming opportunity for farmers in New Hampshire. Up to that point most farms were self-reliant farms where people were growing enough food for themselves and if they had a little bit left over it would get sold,” Wessels said. “It vaulted the central portion of New England — which would have been all of New Hampshire pretty much south of the Notches — to become one of the major woolen textile producing regions of the world.”
The wool industry would experience ups and downs, usually caused by changes to tariff laws. From 1845 to the 1960s, Wessels said the state experienced a gradual period of farm abandonment, which allowed for reforestation.
“The bulk of our forests today are all generated from that farm abandonment,” Wessels said.
Ironically, almost all the trees cut down for pasturage wasn’t used for timber. They were burned. Farmers could still make money off of the ashes. Pot ash was a key export for making gunpowder and soaps back then.
The second historical development that helped shape our forests today was a significant clearcutting operation that almost wiped them out altogether, especially in the White Mountains.
Wessels said timber was a key industry in the state even during colonial times, when the British would use our trees to construct their navy.
“Really the basis of the New Hampshire economy at the start was timber, because although New Hampshire’s soils were not as fertile as, let’s say, Vermont … New Hampshire soils grew really good pine and oak and both [were] valued for shipbuilding,” Wessels said.
The large pines were used for masts and the oak was used for framing. But those trees were cut selectively.
“They were going after the best trees and they weren’t really clear cutting,” Wessels said.
But by the late 1800s, the timber industry was clearcutting forests in the White Mountains, and it lasted into the 1920s. This gave rise to groups like the Forest Society, which sought to preserve the forests, and new federal conservation policies.
Another thing deforestation did was reduce forest diversity. Historical records suggest a much wider variety of tree species co-existed before the wholesale removal of forest areas, according to Wessels. Today, forests have become more homogenous.
New Hampshire’s state tree
In a way, this clearcutting might have had a significant impact on which tree was chosen to be the official state tree. In 1947, the legislature named the white birch (also known as paper birch) the state tree. White birch is an early successional species and it’s not very tolerant of shade, according to forester Gabe Roxby. This means they thrive in open, sunny areas, but they struggle when tree cover gets too dense. Their boom in populations was a result of the clearcutting and its prevalence may have played a hand in the legislature’s choice.
“I wouldn’t doubt that the clearcutting of the White Mountains had a big impact on that choice because paper birch was one of those trees that came back like gangbusters after that clear cutting,” Wessels said.
Now, the white birch is in sharp decline, according to Roxby, who keeps track via the annual reports put out by the U.S. Forest Service.
A few other things have affected forest composition over the years. Bowman said the state used to have a lot more elm and American chestnut trees. Dutch elm disease was introduced to the region from diseased logs in the 1930s, according to the UNH Cooperative Extension. Chestnut blight did away with most of the chestnut trees in the region around the same time. The trees now can only grow to a point and die off to the roots, repeating this cycle, never to reach maturity.
The next big change in the state’s tree composition may be the loss of the ash tree. New Hampshire is home to white, black and green ash (white being the most common) but all are susceptible to a deadly invasive insect called the emerald ash borer. Ash have been wiped out in other parts of the country exposed to the beetle, so the state has attempted to slow its progress by banning cross-county transport of firewood, which ash borers can hitchhike on.
Environmental officials are also experimenting with different ways to fight back against the bugs, but the demise of the ash seems otherwise inevitable.
“Ash doesn’t have a super bright future,” Roxby said.