The Hemlock Ring of Upstate New York

The Adirondacks are a small, well-known mountain range in the northernmost region of New York State. The range is prized for its remoteness as well as for its opportunities for recreational tourism in an otherwise very densely populated section of the country. Like many northern mountains, the mountains here have plenty of coniferous trees that take advantage of the harsh climatic conditions, including spruce, fir, and hemlock. Of these three tree types, hemlock has an interesting, quite wide presence not only in the mountains, but also around the edges of the mountain range.

One of our excursions in the area lie directly within this known hemlock ring. We encountered many hemlock within the Fort Drum military base, in a park-like setting that is used for passive recreation by those living in and around the base. The base is the site of a National Historic Site, a mansion and surrounding grounds that once belonged to James LeRay, a Frenchman who had been sent by his father to the United States to collect on a wartime loan that went unpaid by the US government. While in the country, he met his wife and became a naturalized citizen. He believed he could regain his family’s lost fortune by investing in thousands of acres in Upstate New York, 300 of which he set aside for his private estate. Since much of this land previously belonged to LeRay, the nearby forest paths surrounding the mansion were also part of his estate, and some were previously cleared of tree cover. To get a read on where forest cover has regenerated within the past one hundred years, follow the wooded paths behind the mansion and the gondola to the grave of James LeRay’s granddaughter. There is a bell tower dedicated to her and a gravestone marking the site. Her grave used to be near the old entrance to the grounds, so she was not forgotten after her death. While the forest looks to be in a natural state now, much of it was altered and cleared during the time period in which the grave was placed. Due to this previous human activity we see what could be called a mid-successional, or middle age, forest type in this area, in which trees classified as old growth are rare.

The tree cover consists of many yellow birch, sugar maple, and hemlocks. The hemlocks in the stand were amazingly healthy compared to many of the specimens found down southeast in the Boston metro, which are often suffering from hemlock woody adelgid infections. I did not find a single instance of woody adelgid on the trees that I observed, suggesting the insect has perhaps not made its way this far north, or is perhaps limited in capacity by the rather intense weather and temperatures in this area that tend to occur due to the nearby Great Lakes.

Based on range maps, it’s also not uncommon to see beech trees and red oaks in this area, but the latter are typically minor canopy associates and do not dominate the forest cover. However, because LeRay Mansion sits within a residential area on the base, it’s very common to see mature oak trees in nearby yards, where they were likely planted and face no canopy competition.

Interestingly, when we look at US government forest maps, we see a dearth of hemlock dominance once the elevation increases in the Adirondacks. This is potentially because of increased competition from spruce and fir trees, and some of the more exposed conditions not being as favorable to hemlocks, as they tend to like soil where water is plentiful and shaded areas. Hemlocks do still occur throughout the Adirondacks, but are often considered minor canopy associates, rather than a dominant species.

In the opposite direction, we descend into lowlands that sit along the edges of the St. Lawrence River, which in this area acts as the border between the United States and Canada. These forests also contain hemlock, but differ slightly in composition from the outer ring of the Adirondacks where LeRay mansion sits. This area is known as the clayplains and supports a greater dominance of various oak species than the nearby higher elevations. To me the oak dominance is much more reminiscent of the forests in eastern Massachusetts, though it’s important to note both areas have been heavily impacted by agriculture and development, which have affected the age, density, and composition of forests in both these areas, and their natural inclinations are not exactly the same.

If you want to explore the comparisons between forest matrices in detail for yourself, I recommend doing a deep dive at conservationgateway.org. This site contains extremely detailed range maps for areas across the country, and helped me start to make sense of the subtle forest changes I was seeing as I traveled across the northeastern US.