Friday, January 15, 2016

The Broad Brook Forest

What follows is an essay by Bob Leverett on a relatively small tract of forest that is literally in his back yard, in western Massachusetts. The text and photos were supplied by Bob.  Enjoy!

The Mature Forests and Exceptional Trees of Upper Broad Brook

An essay by Robert T. Leverett

Cofounder and Executive Director of the Native Tree Society
Cofounder of the National Cadre of American Forests
 Cofounder and President, Friends of Mohawk Trail State Forest

The Laurie Sanders White Pine on Broad Brook, Northampton MA
The Laurie Sanders Pine
Upper Broad Brook, Northampton, MA


There is an attractive little stream that runs for about 5 miles, starting and ending in Hampshire County, Massachusetts. Its name is Broad Brook. It is not broad, and few people, other than local citizens, know of its existence. But Broad Brook has a story to tell. First, it is the primary stream source of Northampton’s popular 800-acre Fitzgerald Lake Conservation Area, and secondly, it harbors a valuable mature forest on its upper stretches, the focus of this article.

Since trees are my passion, no essay of mine would be complete without a species list. Below are the ones that we’ve observed so far along upper Broad Brook corridor and part of the Fitzgerald Lake Conservation Area. Each species is followed with an abundance code: A=very abundant, C=common, I=infrequent, R=rare, E=Extremely rare.

1. White pine - C             12. Tuliptree - I                23. American basswood - I
2. Eastern hemlock - C    13. Sugar maple - C         24. American beech - C
3. Pitch pine - E              14. Red maple - A            25. American hornbeam - I
4. Northern red oak - A   15. Striped maple - I         26. White ash - I
5. White oak - C             16. Slippery elm - I           27. Green ash - I
6. Black oak - C              17. Bigtooth aspen - I       28. Hop hornbeam - I
7. Scarlet oak - I            18. Quaking aspen - E       29. Black cherry - I
8. Chestnut oak - E        19. Pignut hickory - I         30. Gray birch - I
9. Black birch - C           20. Shagbark hickory I       31. American chestnut - I
10. Yellow birch - I         21. Eastern cottonwood - I  32. American sycamore - E
11. White birch - I         22. Sassafras - E

Downstream from the lake, there may species such as silver maple, swamp white oak, pin oak, and hackberry. If so, it would most likely be near where Broad Brook joins the Mill River. I have yet to check out the lower reaches of the stream, but the riparian species just mentioned characteristically grow in wetlands within the Connecticut River Valley. The cutoff for where you see them and where you don’t is an irregular line that has to do with the level of the ground water, the frequency of flooding, and the depth and composition of the soils.

At this point in our tree cataloging, I expect that the maximum number of tree species for the entire stream corridor falls just shy of 40, which is not bad diversity for the latitude. And this does not include non-native tree species in the area, which will likely increase the count by between 5 and 10.

The Rest of the Story

I like to think of Fitzgerald Lake as a gift to us from little Broad Brook, which begins about a mile north of our house in a wetland. From simple origins, it collects water as it meanders for about a mile and a half before gently entering the head of the lake. Sloping ridges surround the brook’s origins. From coalescing paths, the brook establishes a recognizable channel and flows southward, eventually passing behind our house before turning eastward where it flows under North Farms Road through a culvert and then gently spreads into a cattail marsh at the head of the lake. For most of this length, the unassuming little stream runs through a small valley that narrows to a steep, though shallow, ravine just north of our house.

Much of the land along the brook’s upper path is owned by Northampton’s Smith Vocational School, which manages the forests through its forestry program. Use of the woodlands by the school has been more carefully thought through than what is seen on the uppermost stretches of the brook on private lands.

So what is the rest of the story? Before relating it, I should point out that most of the forests in the primary conservation area east of North Farms Road are in a state of recovery. While there are small swaths of more mature woodlands that are pleasing to the eye, especially those bordering the lake, most of the area has been heavily cut in the past. So, despite its obvious charms and considerable wildlife appeal, Fitzgerald Lake Conservation Area is not the place to go to see outstanding trees. Instead, the forested corridor along the brook west of North Farms Road is where you want to walk. 

West of North Farms Road


Let me make it plain, the area I am about to describe is not old growth. It has had more than its share of abuses over the decades, as virtually every acre of the Massachusetts landscape has experienced, but given time, Mother Nature heals the scars, and in our geographical area, this means the return of the forest. Today, visitors are treated to a surprising number of stately trees that tease the imagination. The path beginning on Veterans Administration land, descending to the brook, crossing it and then heading north along the border of the Smith Vocational School’s property offers the visitor patches of mature woodlands suggestive of New England past, the kind that Thoreau mourned the loss of. In other spots, the forest is young with little to capture the attention. The juxtaposition of areas of mature and young woods offers opportunities to observe the natural successional track of a forest.

Poets often wax eloquent when describing our New England woodlands, but the distinguishing features of the forest along upper Broad Brook are best explained with numbers. Ciphers may elicit yawns from folks who prefer qualitative descriptions, but without the tale of the tape, the Broad Brook trees lose much of their significance. They become little more than a green backdrop for casual woods walkers. To acquire a real understanding of Broad Brook woodlands and individual trees, we must take a plunge into the world of lists, measurements, and numeric comparisons. We begin by examining the roles of several prominent species of the trees, starting with, for me, what is the king of the New England woodlands, the lofty white pine (Pinus strobus).

White Pine

Photographs can better convey the feel of what this species contributes to upper Broad Brook. Our first image shows a large white pine that is about a 15-minute walk up the brook from our house. My wife Monica and I like to name trees and this one is no exception. However, the name of this tree has evolved over time. We try different names on for size. Eventually one sticks. We now call the pine the Aimé Bonpland Pine in honor of the French botanist and explorer who accompanied Alexander von Humboldt on his South American exploration.

Monica Leverett, Joan Maloof at White Pine on Broad Brook
Monica Leverett, Joan Maloof at white pine

The heavily plated bark suggests that the big white pine is approaching old growth status. In the photo, Dr. Joan Maloof, creator of the Old Growth Forest Network, and Monica serve as models to showcase the tree’s size.

As of my December 2015 measurement, the pine’s girth was an impressive 11.6 feet and its height was approximately 118.5 feet. The big pine’s surroundings offer a touch of old growth characteristics. Mountain laurel, abundant mosses, and woody debris in different stages of decay point to successional processes that have been at work in the immediate vicinity of the pine for perhaps two centuries.

The white pine’s circumference sets the bar for that dimension within the stream corridor for single-stem trees. There is a hemlock farther up stream of approximately the same girth. There is also an old weevil-damaged white pine with a girth slightly exceeding 11 feet on the east side of the stream. Most conspicuous Broad Brook pines are from 6 to 9 feet around. As a consequence, I would describe Broad Brook’s woodlands as supporting lots of middleweights and a few light heavyweights.

If there is an exception, it is a tree within sight of the Bonpland Pine. As you approach it, it looms larger and larger. Stretching the tape around its trunk at the customary 4.5 feet above base, we got a whopping 15.5 feet. But it has two trunks, so strictly speaking it isn’t one tree. Single or double, it stretches the tape further than any other tree in the Broad Brook corridor.

Will Blozan, President of the Native Tree Society, first measured the second tree, also a white pine, in October 2007. It was then 135.5 feet tall. It is now 137.0 feet, but it is not a single tree. It has two main trunks that are fused for the first 12 feet or so. Most people looking at the trunk at eye level will likely see the tree as a single, rather than a double, but a quick glance aloft shows two unmistakable trunks. Its form is not uncommon where pines grow close together. Two pines sprout from separate seeds developing separate root systems, but the trunks press together and the bark grows around the point of contact, creating the appearance of one tree. At least that is what we think is going on with the species.

I have showcased the big double in past posts to the Native Tree Society Bulletin Board Service ( In recognition of its matriarchal role, it has been named the Grandmother Tree. On the State’s champion tree formula, the pine, treated as a single, earns about 335 points. This would put the tree in a fairly exclusive size class, close to being the state champion. But alas, it is a double.

Let’s take a look at Grandmother. Joan and I pose to give perspective for judging the size of the huge fused trunk.
Bob Leverett, Joan Maloof at Grandmother Pine on Broad Brook
Bob Leverett, Joan Maloof at Grandmother Pine
I should point out that pine.
white pine is one of the East’s two tallest tree species, the other being the tuliptree. The current national height champions of both species grow in the Great Smoky Mountains National Park of Tennessee and North Carolina: the pine measures 189.0 feet in height, and the tuliptree, 191.9. By comparison, Grandmother’s 137-foot height seems very modest, falling 52 feet shy of the Smokies

Comparisons on a local level have greater relevance. Grandmother’s stature is enough to make her one of only a dozen trees in the lower Connecticut River Valley in Massachusetts that Native Tree Society members have accurately measured to her height or more. So if you factor in geographical location her status goes up.

Let’s now take a look upward into Grandmother’s crown following her twin trunks.

I think that this big tree (or trees) is around 170 years in age. If so, she began life just before the American Civil War.

I haven't modeled the Grandmother pine for trunk and limb volume, but I think she holds between 750 and 800 cubic feet. To put this volume into perspective, the Bonpland white pine has between 400 and 450 cubic feet. Most of the conspicuous pines along Broad Brook have 200 to 250 cubic feet, and at most 300. This range is true of most mature white pines across the southern New England landscape, which raises the question, how large can the species grow volume-wise?

The largest we have modeled in New England, the Grandfather Pine in Monroe State Forest, has approximately 1200 cubic feet in its trunk and limbs. Grandfather is a single tree and is in a special class – the prestigious 1000-Cubic Feet Club. A couple other huge pines are in the 900 to 950-cube class. Grandmother may eventually reach this volume, but she is a double. Regardless of the number of trunks, Grandmother makes a lasting visual impression. Pines of this size add 5 to 12 cubic feet of new wood each growing season, and in some cases more. Ten cubic feet of new wood translates to approximately 120 lbs of elemental carbon sequestered annually. Grandmother is still a working lady.

Farther up the stream corridor, within sight of Grandmother, eleven attractive white pines come into view. They exhibit the long straight trunks characteristic of their species – trunks coveted by the British Navy in the 1700s for ship masts. Five pines in the cluster exceed 130 feet in height, with the tallest at 140.0 and a second at 139.1. We have named the 140-footer the Laurie Sanders Pine in her honor as a standout naturalist and educator here in the Connecticut River Valley. Laurie’s pine is one of only four we have measured in the Connecticut River Valley corridor of Massachusetts to make the 140-foot height threshold. Laurie’s tall, straight pine is featured in the first photo, above; and here's Laurie at her pine...

Laurie Sanders at White Pine
Laurie Sanders

Including the big double, this section on the west side of Broad Brook boasts 6 pines over 130 feet and at least another half dozen over 120. All have grown significantly since I first saw them. The result is a developing woodland ambiance that suggests images of New E
ngland past. Eventually, Laurie’s pine and its 139-foot companion across the path may make it into the elite, if not snobbish, 150-Club. If the current rate of annual growth doesn’t diminish, the threshold event could occur by the end of the 2025-growing season. I hope Monica and I are around to act as witnesses.

Across the brook to the east, three more pines in this upper section of Broad Brook exceed 130 feet, bringing the total to nine north of the trail that comes down from the Veterans Administration land. Downstream, six pines on the east side, and six on the west side bring the total number of trees making the 130-foot threshold to 21 growing along a mile-long stretch of the brook.
Large White Pines on Broad Brook, Northampton MA
In this photo, the pine on the right measures 8.9 feet in girth and stands 132.0 feet tall. The left pine is a huge double with a breast-high girth of 12.6 feet and a height that just reaches 135 feet.

Standing at the base of one of these tall pines, one’s eye naturally follows the long trunk upward 90 to 100 feet into a spread of branches. When the sunlight catches the foliage on the needles of the upper branches, the experience can be almost transcendental. Through small gaps in the branches, one gets glimpses of the higher tops that are often another 30 feet to the tips. The vertical dimension creates a forest cathedral effect, so appealing to photographers and artists in their depictions of primeval woodlands. Here is a photographic example of what I am attempting to describe.

If Broad Brook’s count of twenty-one 130-footers is exceptional, just how exceptional is it? There are likely between 125 and 150 locations in Massachusetts with 130-footers. So far I have documented 67 sites, but most of them have less than six trees in this height class. As of December 2015, Broad Brook holds down 7th position for number of 130-foot pines on a site. Based on the amount of searching done to date, it appears that the Broad Brook site is significant and should remain so. This brings up a question.

How does one go about covering an entire state looking for outstandingly tall trees? I get lots of tips, but more importantly, the distribution of tall trees favor certain types of terrain, soil types, and land history. Western Massachusetts is strongly favored. Eastern Massachusetts is very densely settled, and forested properties have suffered the consequences. Most tall tree sites in Massachusetts that we have confirmed are in the Pelham Hills, the Connecticut River Valley, the Berkshires, the Hoosic and Housatonic River Valleys, and the lower elevations of the Taconics. To put a number on this point, as of this writing, we’ve broken 130 feet only on three sites east of Worcester, MA. NTS member Andrew Joslin of Jamaica Plains, MA, measured a white pine over 130 feet in Concord. Recently, Dr. Doug Bidlack added two more sites. In fact, Doug has the eastern Massachusetts height record with a surprising 144 feet for a white pine in Lincoln. Doug assures us that there are several 130s in the stand.

Since Broad Brook has one 140-footer, the Laurie Sanders Pine, we can count the site in with those elsewhere that have trees making it into the 140-foot class. There are 31 sites that the Native Tree Society has confirmed in Massachusetts with trees reaching into this height class. 

Eastern Hemlock

It is Monica’s and my opinion that the hemlocks (Tsuga Canadensis) along Broad Brook increase the area’s aesthetic appeal more than any other species save possibly the white pine. Here they thrust their feathery crowns to 100 feet and more. A few exceed 110. Most are 5 to 9 feet in circumference. They are mature trees, and are drop dead gorgeous.

The absolute champion of size, named Grandfather Hemlock, grows near the 139-foot pine previously mentioned and is 11.5 feet in girth. Also close to the pine is a double-trunk, 119.5-foot hemlock, and a single trunk 113-footer. I doubt if the Broad Brook hemlocks can do much better than this. There are quite a few now around 100 feet tall that still have plenty of room for growth, but judging from what I see with the older ones, they have a ceiling of between 110 and 115 feet. The 119.5-footer appears to be a statistical outlier.

Although in their youth they have a graceful appearance, to my eye, the character of the hemlocks increases with time. Grandfather has an ancient appearance, perhaps like a Tolkien Ent. It is the maturity of Broad Brook hemlocks more than their size that is the secret of their charm.

In the next image, Monica stands behind Grandfather, making him look very large. He is, in fact, 11.5 feet in girth and 106.5 feet in height.

Monica Leverett at Grandfather Hemlock, Broad Brook

Aloft, this old hemlock is a mass of unruly limbs. There is a feeling of forest wisdom held within its branches. Elsewhere, the trunks of mature hemlocks establish aesthetic corridors. From a distance, their numbers create a woodland ambience. As one draws near, their trunks loom larger, and individuality is established. Close by, they exhibit a commanding presence, securing their role in creating a forest aesthetic that the hardwoods struggle to match.

Hemlocks in Broad Brook Forest, Northampton MA

Tulip Tree 


Lumbermen call the species yellow poplar, but it isn’t a poplar at all. It is a member of the magnolia family. Range maps for Liriodendron tulipifera show this lord of the eastern hardwoods as reaching southern Massachusetts and then abruptly stopping. Farther north, the species exists primarily as a yard tree. I should mention that there is an outlier stand of Liriodendrons in Keene, New Hampshire near a lake, but their scraggly appearance suggests that they escaped from planted trees in the area. They show no signs of natural adaptability to the region.

The conclusion of our distribution studies, shared by my companion researchers the late Gary Beluzo and Bart Bouricius, is that the tulip trees along Broad Brook are among the last that grow naturally in the northeasterly part of their range. We also know of a small area in Whately, MA, and after that the species drops out, climate being the probable cause.

Altogether, counting saplings, arborist Bart, Professor Gary, and I have identified over 90 tulip trees in the corridor from our house to a mile upstream. It is a stretch to identify them as an ecologically significant community, but the story does not end with the simple existence of the Broad Brook tulip trees.

Liriodendron is no ordinary species. It is arguably the giant of eastern hardwoods. Thomas Jefferson called Liriodendron the Juno of species. No eastern hardwood in today’s woods achieves greater stature. The tulip tree reaches its zenith in the southern Appalachians where we measured one specimen to 191.9 feet (climbed and tape-drop-measured by Will Blozan). Quite a few exceed 180 feet in those mountains, making the southern Appalachians the center of the species development, but how does Liriodendron fare farther north?

From its southern center, the tulip tree holds significant heights into southern New York and New England, and westward into Ohio and southern Michigan. In our region, we have measured trees to 155 feet in southern Connecticut and along the Hudson in Hyde Park, New York. Westward into Ohio, we have a single tulip tree at 170 feet, but a number of sites where the species exceeds 150 feet. Heights in the 160s are achieved from Georgia to Pennsylvania.

Basically, our data suggests that between 41 and 42 degrees latitude, the species loses its competitive advantage in interior woodlands and exists as remnant old-field stands for a time. The species also finds a niche along river corridors above flooded regions, and in general, where light is plentiful. But even farther north, above 42 degrees north latitude, the tulips refuse to go out with a whimper. In Zoar Valley, New York, at latitude 42.3 degrees, the tulips reach to 157.5 feet in height.

While diameters for the Broad Brook tulips are modest at only slightly more than two feet, they make up for it in stature. Five trees exceed 120 feet in height. Amazingly, all grow on our property. Two more tulip trees in the corridor will likely reach 120 feet in 2 to 5 years. Elsewhere in nearby Amherst on the Emily Dickinson Estate, an old tuliptree reaches to 127 feet. Northward from Amherst, the tallest members of Liriodendron typically top out at between 100 and 115 feet, as yard or estate trees. In Gary’s and my work, the region in and around Northampton, Whately, and Amherst appears to be the boundary for naturally seeded tulips going in the northeasterly direction.

So, what absolutes are achieved? One of the five 120-footers along Broad Brook reaches 130.7 feet. This lone tree grows on our property, and so far as I have been able to determine is the tallest of its species at its northeastern location. Heights of the others are 129.0, 127.4, 125.6, and 120.6 feet respectively. All these trees are exploiting an area of protection within a ravine. It is impossible to identify the original seed source.

The next image shows two of the tall tulip trees behind our house: the ones in the center and left of center. The one on the left is the 130.7-footer. The one on the right is 125.6 feet tall. 

Large Tulip Poplars in Broad Brook Forest, Northampton MA
Tulip trees
These trees struggle to compete in Broad Brook’s rocky soils and densely shaded woods. Their existence speaks to a time when the banks down to broad brook were largely bare of trees. The open space gave the species its opportunity to seed in, but the trees, though fairly tall, have never attained large girths. In contrast, only a few miles to the south on Smith College’s Lyman Estate property, tuliptrees grow on a terrace of the old Mill River. There they reach large size, with one making 14.2 feet in circumference and 136.8 feet in height; we have named this tulip the Sophia Smith Tree for the founder of Smith College.



Pignut Hickory



Two species of hickory grow in the Broad Brook corridor, shagbark (Carya ovata) and pignut hickory (Carya glabra). One pignut hickory (or maybe red hickory, Carya ovalis) on the west side of the brook north of the Grandmother tree is hardly noticeable with its slender trunk that measures a meager 4.8 feet around. But standing beneath this little hickory and looking upwards, one’s eyes can’t help but search for its highest tips. This tree is 120.0 feet tall. Another hickory in the vicinity reaches 116.2 feet with a 7-ft girth. Then there is a super slender hickory that makes 107.0 feet with only a girth of 4.2 feet. This represents a height to diameter ration of 78.5 to 1 - an impressive height for the small girth. Here is a view looking up the ramrod straight trunk of the 120.0-foot pignut.

Pignut Hickory Tree in Broad Brook Forest, Northampton MA
Pignut Hickory

Other pignuts in the area are between 100 and 112 feet. All are small in diameter. The number of hickories in the area begged for a name. I originally thought of hickory hill, but that sounded too pedestrian. I settled on Miss Piggy’s Woods. Now that has class.

In summary, the lightly distributed pignut hickories are slender trees reaching from 4 to 7 feet in circumference, but what they lack in girth, they make up in height. The mature hickories are from 90 to 110 feet with at least 3 trees exceeding 110.

Black Birch

Black birch (Betula lenta) is common to the Broad Brook woods. It is a species with several common names including sweet birch, cherry birch, and mahogany birch.

Search the tree guides and Internet sources for descriptions of black birch, and you will frequently read that it is a medium-sized tree that reaches from 70 to 80 feet. Some sources list it as only a 50 to 60-foot tall tree. These descriptions are simply wrong. The black birch is genetically programmed to achieve greater heights. So far, I have measured 65 birches along Broad Brook. Their average height is 87.7 feet, and there is one that pushes the envelope, a star performer. A birch growing near the tall pignut hickory mentioned previously reaches the surprising height of 108.0 feet. We’ve only found 3 black birches in all Massachusetts exceeding this height, with the tallest being 110.0 feet located in Mohawk Trail State Forest. So laying aside inaccurate descriptions, what can this species achieve in height, circumference, and age?

Mature black birches commonly reach between 75 to 95 feet in rich woods throughout Massachusetts. Occasional specimens make 100 feet on the best growing sites, but then upward growth shuts down. Birches exceeding 105 feet in Massachusetts are very rare. It appears that the species has a built-in ceiling of about 110 feet in southern New England. Farther south in Pennsylvania, add 5 feet, and in the Great Smoky Mountains, we have measured them to 118.9 feet.

Interestingly, the span of maximum heights from New England to the southern Appalachians is only about 10 feet for black birch. Other species that have ranges extending from New England to the mid-South, often show a 20 to 30-foot height advantage favoring the southern end of the range. We are not sure how black birch fares as we move into the Midwest. We don’t have that much data, but what we have suggests the mid-western limit is around 115 feet.

Age-wise, we have dated black birch to 388 years in the southern Appalachians. In Massachusetts, we’ve documented 332 years. Many black birches exceed 200 years. We haven’t yet determined maximums for Broad Brook, but my sense is 130 to 180 years. The bark fragmentation pattern up and down the trunk provides age clues to most species, but the change in black birch is pronounced. Many people do not recognize old black birches. They are accustomed to seeing young gray-black bark with the lenticels clearly visible in their horizontal patterns.
108-foot Black Birch Tree in Broad Brook Forest, Northampton MA
108-foot Black birch
Since Monica is a retired music professor from Smith College and a still very active concert pianist, the names of musicians are always on our minds. Naming trees for admired composers seems a no-brainer. For instance, I love the music of Franz Schubert – always have. So naturally, the black birch’s name has to be “Schubirch.”





Northern Red Oak

Big red (Quercus rubra) is a commercially valuable species and readily catches the eyes of lumbermen. It is an important wildlife tree. Oaks of all species convey power and solidness. There are no giants along Broad Brook, but mature specimens are scattered along the path from North Farms Road to the head of the stream. Most of the older trees are between 7 and 9 feet in girth and 90 to 110 feet in height. The tallest I’ve found reaches 117.0 feet, and that tree is on our property. I expect there are a few others close to this height, but I like to think that our trees benefit from the proximity of Monica’s music room.

On our property, alone, at least ten northern reds exceed 100 feet in height. Add five tulip trees, three white pines, a red maple, and a white ash, and we have 20 trees over 100 feet in a small area of about half an acre. Oh yes, and there is a black oak (Quercus velutina) that reaches to 107.1 feet. It is arguably a red-black hybrid.

On adjacent Smith Vocational property, a handsome large oak is 10.2 feet in girth and reaches to 102.2 feet in height. We regularly pass by this imposing oak on our way to the upper reaches of the brook. It has become an old friend, and we call it Beethoven, but it is not alone. Other isolated large oaks dot the path going upstream until private property is reached. The big trees stop there. Let’s meet Beethoven:
Beethoven Red Oak in Broad Brook Forest, Northampton MA
Beethoven, the Red Oak

To put a wrap on the oaks, from our house north following the route to the area around the Grandmother pine, there are no less than 50 mature oaks that one passes, any of which would make lumbermen salivate. The forest around many of them is undistinguished regrowth; that, along with their straight trunks and often buttressed root systems magnify their visual impact.

Other Species 


Sugar maples (Acer saccharum) are present in the corridor, but not abundant. The tips of their crowns flirt with the 100-foot level, but with a few exceptions, they never reach the size of the pines and northern red oaks, and neither do the white ashes (Fraxinus americana). Broad Brook is not white ash territory. Moving on, red maple (Acer rubrum) is abundant, but tree size is modest. There are several stately white oaks (Quercus alba), one I measured to 106 feet in height and 8.3 feet in circumference, but you will encounter no record breakers for the species.

Throughout the woods attractive yellow birches announce their presence with their golden trunks that show dainty, peeling bark. Most of the yellow birches are relatively young. I have measured them to heights of slightly less than 90 feet, but what they surrender in physical size, they more than make up in sheer beauty.

These and other species fill in the gaps and provide variety. They remind us that the forest is a gestalt where all species find their place.


Ecological Considerations

Beyond the obvious aesthetic appeal of the forest, there is deeper importance for Broad Brook’s mature trees. The larger ones, the matriarchs and patriarchs, serve important ecological functions. Their roots extend far in all directions, connecting to lesser trees, providing added nourishment to weaker neighbors, and helping to create an interconnected web that carries the genetic heritage of the woodland community forward. The crowns of Broad Brook’s mature trees create a high canopy that creates a different habitat for at least a few bird species and create a wider temperature gradient from canopy to forest floor. Remove the elders from the community (the trees that have endured the longest), and the forest may lose long-term resiliency.

With due consideration to the foregoing description, Broad Brook’s forest is still a work in progress, which raises a question. What successional trajectory is it on? Older forests that have been shaped by natural events over centuries exhibit complex structures that provide a balanced variety of wildlife habitats. Ground plant colonization tends to be richer with a wealth of lichens, mosses, liverworts, and ferns. It is true that in mature and old growth, one becomes more conscious of the death and decay cycle of forest ecosystems. This doesn’t sound attractive, yet natural events that create a complex structure, and many age classes, are more resilient.

Will Broad Brook’s woodland eventually develop into an old growth forest? If left alone, it will eventually, but for now, it is still a work in progress. The advantage is that it provides us a window into the successional processes involved.

In the following image, we see a large wind-throw that creates a new habitat and a microclimate. The cavity at the base of the root ball stays cooler in the summer. The soil on top of the ball can offer a seedbed to species like yellow and black birch, which have tiny seeds needing mineral soil to germinate. 

The embedded rocks are glacial till because the entire region was a dumping ground for receding glaciers. The embedded stones in the root system look like river rocks, but are part of the glacial scree.

Next is a closeup of fungus on the decayed trunk of a small hemlock. Artistry expresses itself in the death cycle of the large trees. Actually, from an ecological perspective, the fallen giants have a lot more work to do as they provide a different kind of food and wildlife cover, and return nutrients to the soil.








In Closing

The foregoing presentation is my case for upper Broad Brook’s mature forest being the City of Northampton’s woodland showpiece. I will close with some scenes from these woodlands.


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