First, Old Growth Hemlocks
Small, but older hemlocks |
A hemlock soon to be downed by wind? |
Counting Tree Rings
Beneath one small, dead hemlock, there was a 21/2 inch diameter branch that had fallen from it. I cut a small disk off the trunk end of it, and brought it home to count its rings to get some idea of the age of the tree. Its annual rings were extremely close together, indicating that this tree had grown quite slowly (which is in keeping with the aged look of its bark, and small stature). It was necessary to use a microscope to count the rings; the count was between 150 and 160!
Annual rings of 150-yr-old hemlock branch |
Now, that's just the age of that particular branch, which had been attached to the trunk at roughly 15 feet up. The trunk itself was about 10 inches in diameter, and the total tree height was perhaps 25 feet. This was a small tree, one that most anybody would not look twice at. Yet it was quite old. Hemlocks are very shade tolerant, and if they're shaded by surrounding trees as they get their start in life, they can remain alive and grow almost imperceptibly for easily a hundred years or more. At some point, the overhead canopy may open up when a neighbor tree goes down, and the hemlock will be "released" by the sudden increase in sunlight reaching it, allowing its growth rate to increase dramatically. So, we know that this now-dead hemlock was at least 150 to 160 years old; we would add to that the number of years it took the tree to grow from a seed to the height where that branch had been. We don't know that number in this case, but it could be as much as another hundred years. We would have to count the rings in the trunk just above ground level to know the actual age of the tree. Another nearby hemlock has been dated to over 201 years old, yet it is only 4.5 feet in circumference (or, approximately 17 inches in diameter). Yet another is over 230 years old.
Hemlock, 201+ years old |
Old Growth Yellow Birches
We were enjoying this exploratory hike. Like a treasure hunt, it excited us at each ridge line and ravine we crossed. Discovering "new" charismatic old trees with your buddies, well, it doesn't get much better than that for me (ok, finding a restaurant that makes great Belgian waffles might top it).
One of the stately old yellow birches |
Yellow birch bark, at middle age |
Weather-beaten crown of an old cherry tree |
Yellow Birch, 218+ years old |
The Champion Yellow Birch
Not terribly far into our hike, the best discovery of the day (no-- the year) suddenly loomed out of the snowy, dark hemlock forest right in front of us. There it was, a magnificently shaped, tall, straight yellow birch. Its most striking feature was its gracefully flared base, formed by large buttress roots that keep it propped up, arrow-straight,
The MA State Champ Yellow Birch |
Jared Lockwood measures the champ |
You can see by the photo that this tree has a significant flare at its base. Because of that, it makes a big difference where you measure the circumference. We determined that this tree is 12.78 feet cbh. It was difficult to see the tree's topmost twig, but Jared measured its height to 86.8 feet, using a laser instrument. The average spread of the crown came in at 57.4 feet.
Champion trees are determined via a formula that considers a tree's height, circumference, and crown spread, and yields a number of points; highest point score wins the title for that species. The formula is as follows;
Point Score = Trunk Circumference (in inches) + Height ( in feet) + ¼ Average Crown Spread (in feet).
Our old growth tree earns a score of 254.5 big tree points, and qualifies to be the Massachusetts state champion yellow birch. You can get a better look at the tree in the short video below (video player may not be visible on some browsers or mobile devices).
Mission Accomplished
Our day's mission was to locate a certain old hemlock stand. After leaving the champion birch, we pressed on and eventually found those hemlocks, and they were worth the hike. But, what we found along the way turned out to be even more impressive and exciting.So, it was an unexpectedly rewarding day, but then, a hike in an old growth forest never fails to make my day.
More Great Trees of Massachusetts
- To learn more about all of New England's birch tree species, see "Birch, Sweet Birch - New England's Forest Birches".
- Read about a monstrous white pine, in "The Thoreau Pine - State Champion of Massachusetts".
and watch the accompanying videos on our New England Forests youtube channel:
The yellow birch is a tree in crisis. Here at 1400' and 8 miles east of Gt. Barrington you may wander the woods for days and find no sapling of this great tree. Deer are hoovering this noble tree to death. It cannot start life on leaf mulch, it must germinate in windthrow or moss. It grows slowly, and can be stunted (+ outcompeted) by nearby sugar maple. I have planted 40 saplings (bought from Michigan), and I have to be diligent in protecting them. I find beautiful specimens by streams and on north slopes, but they are all more than 70 years old. How will this tree survive to grace our northern woods? In Quebec the tree is the arbre emblematique, and its numbers have plummeted. A New England bereft of its yellow birch will be a sad legacy. The grace and beauty of this tree are priceless (and the wood is valuable as well - made into veneer for millions of wood office doors, 3'0 x 6'8"). I love the dainty flowers of amelanchier, and the grandeur of white pine. But yellow birch is closest to my heart.
ReplyDeleteHi Eric,
ReplyDeleteI haven't heard of problems with yellow birch in New England, and see them reproducing quite commonly in appropriate habitat. As you mentioned, they need the right substrate (i.e., mossy nurse log, exposed mineral soil, etc) on which to germinate seed. There are so many other tree species in trouble, it would be disheartening to learn birches are too.