Ranging across the northeast; this slow-growing conifer creates great winter cover areas for a range of species. Eastern hemlock is not that notable for its sawtimber production because of its extremely slow growth rate and low value ($60 per MBF; $12 per cord). Some of these trees are known to be extremely slow growers; some less than one inch in d.b.h. are reportedly over 100 years old; with the oldest known tree being 988 years and 38 inches in d.b.h. Growth rates of 2.5" per decade are possible in areas of little competition; especially following the release of the understory. All of that said; it is easy to see that hemlock is not a great species for timber production; especially considering the higher value and substantially faster growth of eastern white pine; as discussed last week. Thus, we will focus on the wildlife benefits of hemlock; namely its use as whitetail deer wintering yards.
While hemlock is used by various species as softwood browse; it is by no means a highly favored species and is typically hard to reach; as limbs can be well out of reach in older stands. In stands with hemlock comprising over 70% of the overstory and abundant "functional cover" (trees over 35 feet in height); land managers can potentially find more value in the stand as winter wildlife cover than as timber; although there are only a few situations in which one can make a true economic comparison favoring it as cover; as, for the most part, it does not produce income as such.
However, if managed properly; deer wintering yards can produce at least some income. Wintering yards are best constructed as uneven age stands; favoring the younger age classes. Below is a table of the age composition of a properly managed hemlock deer yard; as can be seen; most emphasis is placed on species in the 20 to 40 feet range; although the notable difference is the presence of a larger volume of 10 to 20 feet tall trees.
Thus, the management of these stands becomes important if one wishes to produce income from them while maintaining the proper age classes. In such managed stands, 50% of the stand should remain in functional cover at all times. The remainder of the stand should be composed of regenerating stock, where new stands are developing, and thinned areas, from which mature trees are harvested. Because hemlock regenerates well in moist shade; it is best to encourage regeneration in areas with a tall overstory (which can help to retain moisture and filter sunlight); ready for harvest once the regeneration reaches the three to five feet tall range; at which time it can be safely released without risk of mortality. In such a situation; the regeneration area is also still serving as functional cover during this transition period. The problem that lies in this type of management is the ability of the seedlings to reach this height requirement without being heavily browsed upon. While this is a problem; the only way to lessen the effects of browsing is to have areas of regeneration with no overstory; which requires the land manager to plant seedlings; as there will be no hemlock overstory from which to regenerate.
It is important for hemlock wintering yards to be located in close proximity to winter feeding areas; whether they be food plots or browse areas. If the yards are not immediately adjacent to the feeding areas, there should be coniferous travel corridors that wildlife can utilize to these feed sources during periods of heavy snowfall.
Overall, hemlock wintering yards are a great asset to land managers focused on wildlife health during winter months. However, they have little economic value because of the growth rate and value of the hemlock timber. Therefore, it may be a situation in which a manager may utilize the hemlock resource if they have such on their property, but would be best to opt against trying to develop such a resource if the property currently lacks one, as it is simply not economically practical.
Timber Rating: D
Cover Rating: A
Overall Rating: B-
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