New England Outdoors – explorelocal

A Surprise Stand of Pitch Pine in Middlesex Fells Reservation

Around the Boston Metro and extending into many areas of New England, the most dominant, and well known, pine tree is the White Pine. In fact, the White Pine is the state tree of Maine, is featured on top of the Massachusetts State House in the form of a pine cone statue, and was one of the most historically significant early exports in the region after colonization. So ubiquitous is the zeitgeist of the White Pine, that many New England residents know nothing of the other pines that thrive on their home turf. Explore enough local parks though, and you may be lucky enough to discover the rugged Pitch Pine.

I first encountered a stand of Pitch Pine up in Acadia National Park in Maine. It is the dominant species atop the summit of Kebo Mountain, the shortest summit in the park. I did not initially realize that the stand is just one of many spots in New England where you can encounter a forest dominated, or codominated by Pitch Pine. In fact, this stand of Pitch Pine is actually at the very northern terminus of the Pitch Pine’s native range, and it is much more common down in southern New England and into the Southern Appalachians. It also forms the canopy of the famous New Jersey Pine Barrens, which is an ecological anomaly on the northern east coast in its shear scale of pine growth.

Upon reading a bit about the Pitch Pine, I learned that it often thrives in areas with poor soil conditions and rugged terrain, but is quickly outcompeted by many hardwood species and White Pine in other areas. It can sometimes thrive in young forests but will slowly disappear from the canopy as the stand matures, similar to other early successional species such as the white birch. This is why it’s usually a bit of a scavenger hunt to find Pitch Pine here. Because of its relative scarcity, I was later surprised to discover small summits dominated by Pitch Pine at Middlesex Fells to the north of Boston! The area is riddled with rocky surfaces, likely composed of Roxbury Puddingstone Conglomerate rocks, which are exposed at summits over generations as soil slowly erodes away around them. Only the tough little Pitch Pines, along with occasional shrubby oaks, seem to tolerate the remaining conditions.

In the Middlesex Fells, you can find Pitch Pine surrounding the old MIT Geodetic Observatory, and around Boojum Rock, both of which are marked on Google Maps. The route to the observatory, however, is very poorly marked in many areas, so you might find yourself bushwhacking a little if you attempt to reach it. It is quite an incredible transition to ascend from the forests of oak, hemlock, beech, birch, and maple in the rest of the Fells to a forest stand that looks like something out of a dry California climate. The environment at Middlesex Fells is also somewhat comparable to the nearby Prospect Hill in Waltham, which features many Pitch Pines around the summit, and showcases a similar transition from the base to the top.

These summit stands contrast strongly to areas where Pitch Pines can actually grow to their full potential. On summits, they tend to remain small and scraggly, perhaps more likely to die off and get replaced via weather events and loss of nutrients. If you want to see Pitch Pines at their largest near Boston, your best bet is to travel to the MetroWest region and explore the Desert Natural Area that spans the towns of Marlborough and Sudbury. This area is naturally very sandy, and the soil conditions cater to the growth of Pitch Pines and scrub oaks. The Pitch Pines here will reach heights closer to what we would typically see in White Pines. However, be on a close look out for Red Pines, which are not native to the spot but were heavily planted in previous decades. You can usually easily tell the two species apart by their bark, as Pitch Pine looks a bit more rugged with deeper fissures, while Red Pine has a more paper-like look.

The Mountain of Oaks, Mt. Wachusett

america, new england

The Mountain of Oaks, Mt. Wachusett

A common stereotype that surrounds the concept of a “mountain” involves either a summit populated with coniferous (evergreen) trees, or a treeless summit surrounded by coniferous forests below the treeline. Indeed this assumption holds mostly true for many mountains in New England, including the famous Mt. Washington, Mt. Cardigan, Mt. Monadnock, and Pack Monadnock. A strange phenomenon exists on the nearby Mt. Wachusett, however. Instead of a summit of conifers, Red Oak dominates the available soil.

Scrubby oaks, limited in growth by thin mountaintop soils and rocky terrain, dominate on the summit of Mt. Wachusett

Why might this be the case? Despite being only about 30 miles south of Pack Monadnock, and only 200 feet lower in elevation, the ecological communities of Mt. Wachusett’s summit differ drastically in character. Pack Monadnock showcases a beautiful array of spruce mixed with northern hardwood species mosaics (beeches, birches, and maples) on and around its summit. The very top of Mt. Wachusett, on the other hand, is a scrubby patch of red oaks surrounding the bare summit. It’s beautiful and fascinating in its own way, but a bit confusing.

That’s not to say Mt. Wachusett is completely devoid of northern hardwoods or spruce. In the ideal growing conditions on the northern slopes, many of these species tend to dominate, particularly the yellow birch. However, old growth oak is still a mainstay throughout these forests. Red spruce is limited to a narrow band on the northern slope just below the summit, but does not breech the ring of scrub oaks at the top.

Old growth yellow spruce, showing the cracks of aging, grows along the Old Indian Trail on Mt. Wachusett

There could be a few reasons for this interesting phenomenon. While much of the research on Mt. Wachusett’s ecology has involved documenting its old growth forest below the summit, there are a few historical and environmental clues that we can use to try and explain the oaks without doing scientific research ourselves! The further south we go in New England, generally the more frequent fire regimes become. While cold ravines and slopes are protected from fires for long periods of time due to their moisture retention, the exposed summit of Wachusett may not retain as much water, allowing fire regimes to historically reign more frequently in this area. Oaks are a species that tend to thrive in areas that are a little drier, and see a little bit more fire, than red spruce and northern hardwoods. In fact, red spruce is particularly susceptible to fire damage.

Another possible explanation is the more recent active disturbances on the summit, which included various recreational structures over the last century. Trees were at different points cleared out to make way for roads and buildings, but the areas of disturbance have evolved over time, potentially allowing some forest to grow back. Red oak is considered to be an early to mid successional species, while red spruce is a late successional species. While climate change may drive the spruce out of this area entirely at some point, without that factor we could have seen more spruce begin to grow in the shadow of these oaks over time, perhaps replacing some of them in the canopy eventually. These are just theories of my own imagination, though, so perhaps scientists will seek to definitively explore this question at some point.

Mt. Wachusett poses this question to us laymen, but it has been studied for almost two decades now thanks to the discovery of four distinct areas of old growth on different slopes of the mountain. This was a particularly incredible find for the area because there were virtually no known old growth areas east of the Connecticut Valley in Massachusetts of this forest type. Many of the other known old growth areas lie in swampy or sandy unfarmable land down towards Cape Cod and Plymouth, and these forests have a much different ecological composition than areas further from the shore.

Wachusett’s old growth areas showcase distinct characteristics depending on their location on the mountain. On the Old Indian Trail, which lies on a north facing slope, we tend to see a transitional hardwood forest, consisting of the aforementioned yellow birches of varying size and age, as well as extremely mature red oak trees, some of which have exceeded their expected lifespan. The harshness of the terrain and frequency of wind events have actually protected these strong old trees that have stood the test of time, knocking out weaker competitors and leaving an open canopy for them to flourish.

Old growth red oak shows crown damage and diversion over time due to the harsh conditions on the mountain. This tree was strong enough to survive generations of storms and wind events

There are four total distinctly studied old growth areas of the mountain. I have not yet visited all of them in person, but in three we can find similar mixed stands of yellow birch, American beech, red oak, and red maple, though the predominance of each type varies. On the southwestern portion of the mountain, we can also find a stand dominated by old growth hemlock.

For easy access to the most well known old growth area of the park, you will need to pay a $5 fee to enter the road that leads to the parking lot across from the Old Indian Trail. You can also start hiking from the base of the mountain closer to the ski resort village. When I went in the summer, the environment was fairly hot and humid with a decent number of mosquitoes, so bug spray is recommended during peak summer. Winter hikes may require microspikes and/or snowshoes depending on recent snowfall amounts. Like most hikes in Massachusetts, spring and fall are the best times for avoiding the most extreme of conditions.

A Hemlock Oasis in the Boston Metro

america, new england

A Hemlock Oasis in the Boston Metro

In my previous life as a city dweller, I would never have known to search for hemlock trees in Massachusetts. I moved from the mountain west directly into an area with a highly dense population and little native forest cover. With the pandemic, there seems to have been a renewed interest in the outdoors and native ecosystems, and many people living in the city now may learn about the incredible hemlock trees, but are none the wiser on where in the world to find one in a dense metro such as that of Boston. It’s even more difficult to find them in the region since the topography has been altered dramatically by human intervention, eliminating the scant locations in which hemlocks may thrive. Having explored many different nature reserves and parks in the area, I currently know of two locations within the I95 highway belt around Boston where hemlocks can be observed: Virginia Wood in the Middlesex Fells and Hemlock Gorge in Newton.

A few hemlocks stand next to the historic bridge that crosses the gorge

Hemlock Gorge maintains a unique topology that favors hemlock trees. This small gorge creates a northeastern facing slope that hemlocks still manage to dominate as the overhead species. However, I didn’t see too many young hemlocks in the understory. They particularly thrive in cool and wet areas, and it’s possible that the urban development around the area has warmed the microclimate, allowing other species to begin overtaking the hemlocks. Additionally, hemlock deaths due to the hemlock woody adelgid infestation may have created even more opportunities for other tree species to take root and thrive here.

In the northwestern area of the park, the hardened sweet birch dominates. Similar to the Hemlock, Sweet birch also prefers moist soils and tends to live on cooler, northern facing slopes. At least one specimen was old enough to showcase the rarely seen cracked bark characteristic of older trees. Trees typically don’t begin to develop this cracked appearance until at least 70 to 80 years of age. The other sweet birches in the area were significantly smaller and had much smoother bark, perhaps individuals that quickly took advantage of a canopy opening as many birches do. The cool, moist nature of this environment also makes fire unlikely, to which sweet birch is particularly susceptible.

At the highest point of the park overlooking the gorge and to the west of the main bridge attraction, white pines dominate. They tend to thrive on virtually any soil type in the area and are prolific seeders in disturbed areas. They also can have an advantage growing on very nutrient poor, rocky soils, which I suspect may be the case here.

The last species found was the American Beech, which was found in many areas throughout the park, but some older specimens were found in the northwestern area of the park, just southwest of the sweet birch stands. Most of the younger beech trees were suffering from beech bark disease, though given the time of year I couldn’t verify whether they also suffered from beech leaf disease. The beeches that exhibited marcescence, or winter leaf retention, had no obvious signs of the disease. The oldest individuals were the target of many word carvings done by passerby over the years, often the most carved into tree because of their incredibly smooth bark.

A young beech tree bears the scars of beech bark disease

Hemlock Gorge is accessible via a parking lot on the northeastern side of the park. However, some people who probably live in the area seem to use this lot to store extra vehicles, so parking may be limited. Alternatively, city-dwellers can take the Green Line from Boston to Eliot Station, but a 20 minute walk to the park from there is required. I was there on a very cold winter day, but even then the park’s popularity was apparent and I encountered a few groups of people and individuals enjoying the park.