Is Eastern Hemlock my favorite tree species? Probably. Thus, I did not BRANCH out (I love tree jokes) all that much with choosing my spring break phenology site. Like my phenology site in South Burlington, I located a hemlock forest to study about 20 minutes from my house in the Boxford Wildlife Sanctuary.
At first glance, there were a lot of similarities between my local hemlock forest and my one in South Burlington. In both sites the majority of the trees are Eastern Hemlocks (they composed about 75-80% of the trees there), with the only other major tree species in the overstory being Eastern White Pine. Also like my South Burlington site, there is only one mature hardwood tree within the site: a Paper Birch. In both sites, there is little visible seasonal change in the tree species since the dominant species are conifers that never lose their foliage.
Furthermore, in both sites, the hemlocks suffocate most undergrowth. However, at the South Burlington forest, invasive plants like Buckthorn, Barberry, and Japanese Knotweed form the limited understory, while at the Boxford forest, invasive plants were not present, and only some Eastern White Pine saplings appeared in the understory from a small opening in the canopy.
There are also some young hemlocks as well, of course.
Downed woody debris are present at both sites, though in greater abundance at the South Burlington site. Though, I likely would have observed more woody debris at the Boxford site if there hadn’t been at least six inches of snow on the ground.
No invasive plants were at the Boxford site; however, the Boxford Wildlife Sanctuary is well within the range of the Hemlock Wooly Adelgid, a small invasive insect that feeds on Eastern Hemlock. The insect has been killing nearly 100% of the hemlocks within its current range. After observing the Boxford site, it was clear that it had been affected by the HWA. While the hemlocks at the South Burlington site all appear to be quite healthy, about 25% of the hemlocks at the Boxford site were dead or almost dead.
There were plenty of hemlocks that were losing needles as well. The hemlocks also didn’t have the deep rich green that I saw in South Burlington. Many trees had a yellow tinge to their needles or their bark appeared more gray than brown. I also spotted a tree that appeared to have holes bored into it, which were then filled by fungi feeding on the dying tree. HWA has been known to weaken a trees defenses so they are susceptible to attacks from boring beetles. That may have been the case with a tree I spotted.
As if I needed any more evidence that the HWA was at my new site, I also saw its characteristic dry, white, woolly balls on the bottom of a hemlock branch.
The pines, at least, seemed to be in a quite healthy condition. Perhaps they could eventually take over the site if the hemlocks die as a result of the HWA.
Judging by the presence of mature hemlocks, and its location on the top and slope of a hill, the site was probably never developed, at least not significantly. The areas around it were most certainly farmland, however. I spotted an old stone wall cutting through the woods on my walk in to the site. An old campfire circle is found in the site, so perhaps part of the site could act as a campsite within the wildlife sanctuary.
I spotted two birds while visiting my site, though I did hear near constant bird chatter in the overstory. Of course, my awful cellphone camera was not able to capture either of them effectively (Thanks Steve Jobs!). I first spotted a woodpecker in a dead snag. I’d like to say that it was Walter Poleman’s favorite Pileated Woodpecker. Though, it was most likely a Hairy Woodpecker since they prefer mature forests like hemlock forests, and appeared to be smaller in size than a Pileated Woodpecker.
I also spotted a Tree Swallow flying out of a nest in a dead snag. Once again, I was unable to capture an accurate photo, though please enjoy a picture of one produced by a professional photographer.
All in all, it was interesting (and slightly depressing) comparing the two hemlock forests I selected. Though, I can’t wait to get back to my regular site.