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Halle Ravine

Posted: Mon Aug 07, 2017 11:27 am
by Erik Danielsen
Halle Ravine is a preserve owned and maintained by the Pound Ridge Land Conservancy, an organization in Westchester County that maintains numerous preserves in the area. Due to its description as containing an old-growth hemlock grove, this is a site I've been eager to visit for some time. As I had hoped, this turns out to be a pretty tall site. My quick visit two weeks ago must be considered preliminary due to everything being in-leaf, but the numbers I was able to obtain tell the story:
Measurements from 7/24/2017
Measurements from 7/24/2017
hallespdsht1.jpg (63.97 KiB) Viewed 692 times
Aerial view; it's a relatively small site sandwiched between estates.
Aerial view; it's a relatively small site sandwiched between estates.
Some of the white ash were particularly striking, and the Mockernut Hickory now stands as the tallest measured in NYS. One surprise was the lack of tall/old northern red oak, with most Q. rubra occurring on the upper slope and upland that show ample evidence of having been clear and probably used as pasture much more recently than the steep slopes and gorge bottom that are more diverse and dominated by hemlock, tuliptree, and sugar maple (and even an old forest-grown white oak), which are likely to have never been cleared but have certainly seen plenty of human impacts (stone wall building, for example). HWA is impacting the hemlocks and visibly changing the light regimes within the gorge, but the Land Conservancy has begun actively treating the hemlocks. It'll be interesting to see what the future holds for the canopy within the gorge.
Hemlock and Tulip really dominate the structure of this forest.
Hemlock and Tulip really dominate the structure of this forest.
I look forward to more thoroughly covering this site post-leaf-off. The tallest Ashes may ultimately compete with Zoar and Kaaterskil for NYS max, and I wouldn't be surprised if the tallest tulips push 150', which would be a nice addition to our 150' site list.

Re: Halle Ravine

Posted: Mon Aug 07, 2017 2:22 pm
by Larry Tucei
Erik- Those are some nice finds. Congrats on the Hickory, the Ash are also impressive. After leaf out I'll bet you will get some more height out of there. Tulips always seem to be one of the tallest species as usual. Larry

Re: Halle Ravine

Posted: Mon Aug 07, 2017 9:11 pm
by ElijahW
Erik,

This looks like a pretty cool site. Perhaps the Red oaks were removed at some point from the slopes? Or maybe its absence is an indication of the advanced age of the forest? Those crowns have some gnarly-ness to them.

I hope the hemlocks pull through. Will chemicals be used or insects?

Elijah

Re: Halle Ravine

Posted: Thu Aug 10, 2017 9:33 am
by Erik Danielsen
Thanks Larry.

Elijah, I suspect that the story with the red (and white) oaks is that when the ravine was more actively used as a woodlot and perhaps for sheltering livestock, as suggested by the stone walls, canopy cover of hemlocks and probably tuliptrees was retained, but other species may have been more actively harvested and red and white oak were probably favored targets. As a result, ash, the hickories, maple, etc had a leg up in reestablishing their place in the deep ravine canopy. Other than the tulips, I suspect most of the canopy-height hardwoods in the ravine are less than 150 years old. The uplands were probably fully cleared until more recently, and those areas have favored oak regeneration. One large red oak with radiant form, gradually being shaded out, at the upper edge of the slope strongly suggests this as well.

The company working on the hemlocks is Trillium, who are often contracted by the state for invasive control in this area. They rely mainly on chemicals but have been involved in different trials with biological controls as well.

Re: Halle Ravine

Posted: Fri Aug 11, 2017 3:30 pm
by Matt Markworth
Wow, super nice white ash! Sometimes they can really surprise.

Matt