Wissahickon Valley Park 11/2019

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Erik Danielsen
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Wissahickon Valley Park 11/2019

Post by Erik Danielsen » Mon Dec 02, 2019 10:35 am

126.5'/10.7'cbh Hemlock, my favorite tree in the park
126.5'/10.7'cbh Hemlock, my favorite tree in the park
In November of 2019 had the chance to visit the Wissahickon Valley section of Fairmont Park in Philadelphia. I had hoped to visit Brandywine Park in DE to seek out some tall liDAR hits Michael Taylor processed, but it didn't pan out- the ready accessibility of Fairmont made it a good alternative. With only one day to get out in it, I mostly acted as a "big tree tourist" working off George Fieo's 2011-12 report [url]http://ents-bbs.org/viewtopic.php?f=151&t=4680[/url], which included geolocations of the trees in the Rucker Index. This park was previously established as one of the northeast's top Rucker Index sites but has not been updated in about 7 years.

Here are the measurement updates obtained on previously measured trees:

Liriodendron tulipifera - 161.2' / 11.1'cbh (previously 162.3' / 10'7"cbh)
Carya cordiformis - 156.1' / 8.3'cbh (previously 150.1' / 7'8"cbh)
Platanus occidentalis - 149.4' / 10.4'cbh (previously 148.3' / 10'1"cbh)
Tsuga canadensis - 138.8' / 8.9'cbh (previously 138.1' / 8'9"cbh)
Tsuga canadensis - 126.5' / 10.7'cbh (previously 125.3' / 10'7") one of the most striking trees in the park, columnar and massive
149.2' White Pine
149.2' White Pine
I also measured several trees in the white pine plantation. In 2011, George measured several of these to the low 140s. Today a few are in the 150s and many in the 140s. I cannot be certain that any of the trees I measured were specific trees that George measured previously. The tallest individual was a bit of a standout with a sinuous crown reaching up for an advantageous spot- its ramrod-straight neighbors in the upper 140s will probably exceed it in the long term. There are probably 3 or 4 trees like to be in the low 150s based on further scanning, but I didn't make careful measurements of them as none appeared likely to exceed the tallest tree. New white pine measurements:

Pinus strobus - 154.1' / 7.3'cbh
Pinus strobus - 149.2' / 7.9'cbh
Pinus strobus - 147.5' / 7'cbh
Pinus strobus - 145.4' / 6.6'cbh

Adding these new measurements to the rest of the Rucker Index trees George reported in 2011 (including a couple measurements from Will Blozan in the early 2000s) yields the following Rucker Index (the second-tallest Green Ash from 2011 was substituted as the 146.4' tree was dead, though still an impressive snag over 130'):

Tulip Poplar 161.2'' Danielson 2019
Bitternut Hickory 156.1' Danielson 2019
White Pine 154.1' Danielson 2019
Sycamore 149.4' Danielson 2019
Green Ash 144' Fieo 2011
E Hemlock 138.8' Danielson 2019
Black Oak 136' Fieo 2011
N Red Oak 135.9' Fieo 2011
White Ash 135.7' Blozan 2003
Pignut Hickory 133.8 Feio 2011

RHI10= 144.5

The final RHI10 is just 0.3 points short of Zoar Valley, and would probably exceed it with additional measurement updates (though the status of the ashes is especially uncertain). The Bitternut Hickory is in great shape and now the second-tallest in the northeast and I believe the fifth-tallest on record (caveat that there are specimens in the smokies last measured decades ago that are probably much taller now). The majority of tulips in this park had relatively ragged tops (perhaps due to some of the rough weather to hit the coast in the last decade), and the tallest specimen had a dead, broken leader just about 1' short of the current tallest branch. I wouldn't be surprised if another svelte tulip in the park is currently taller than the 162.3' recorded in 2011. I just didn't have time for intensive searching.
156.1' Bitternut Hickory
156.1' Bitternut Hickory
The Hemlocks of Wissahickon are still numerous and represented by all age classes, including quite a lot of reproduction. I would imagine there's some regular treatment going on, though I didn't see any indicative tree tags or anything else like that. This visit to the park was also my first encounter with the dreaded Spotted Lanternfly- in the midst of a grove of large tulip, beech, and oaks, the lanternflies were making a unified assault on a number of midstory invasive Ailanthus and Corktree trees while ignoring native hardwoods, as far as I could see. I don't doubt that this insect pest can and will have some negative impacts, but given its generalist nature, preference for invasive tree species, and the fact that our native insectivores seem to find them delicious, I suspect the hype over their threat to our native forests has been overblown. They may have much larger impacts on things like fruit production, but as an ecological threat I doubt they're in the same league as EAB or HWA. More like Gypsy Moths, or even less so.

Interestingly, where the ravine with the tall sycamores at its upstream end (and quite a few black walnuts) meets the main gorge, there was at least a bit of Black Maple or black/sugar intergrades present on the slopes (see the flickr album for the telltale fuzzy undersides and petioles). While "hard" maples don't seem to be a significant natural component of the park's flora, proximity to intermittently flooded gravel bars and indicators of calcareous substrate prompted me to wonder whether the black maple presence (especially in association with the walnuts and sycamores) may have been a minor component of the original flora specializing in the riverine habitats.

More photographs from this visit are available in this flickr album: [url]https://www.flickr.com/photos/135293803@N05/albums/72157711680034561[/url]

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