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Posts Tagged ‘new york botanical garden’

Tulip tree flower.

Tulip trees (Liriodendron) are a marvel, both a-flower and afloat. Their large and solid trunks were prized by our harbor’s first mariners for making dugout canoes. English colonists even dubbed the trees, “canoewood.” Here’s an educational video by Lenape Lifeways about tulip tree canoe construction:

http://www.lenapelifeways.org/videodugoutcanoe.htm

Recently the Shinnecock Nation in eastern Long Island crafted tulip tree canoes to revive the tradition. Note the long, seamless canoes that our forbearers paddled on this estuary in the 1626 illustration (found by my co-authors of the East River book) below.

Felling tulip trees in New York City isn’t welcomed today, but strolling among them certainly is! You’ll find them in Central Park, Prospect Park (an earlier entry showed a red-tailed hawk perched in a tulip tree in Prospect Park), and other large greens. Perhaps the best place to appreciate them is Tulip Tree Allee in the New York Botanical Garden. It’s wondrous to see such delicate flowers growing on such a giant — when hiking the Appalachian Trail you can see them reach 180′ tall. Within New York State, the greatest number are concentrated in the lower Hudson Valley and western Long Island. A great concentration can also translate to diverse coloration, as the species hybridizes easily.

Though the cucumber-scented flowers resemble the tree’s European namesake, the species is actually a cousin of the magnolia. One beautiful coincidence is how a tulip tree’s life mirrors that of a human — it takes fifteen years to flower and can live 100 years.

If you want to be part of this tree’s future, please consider joining the Eastern Native Tree Society or the Appalachian Trail Conservancy, or filling out this New York Botanical Garden volunteer application.

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Lightning strike in NYC. Photo by Sara Scovronick. 

 

By Sara Scovronick

I live I high up in an apartment on 8th Avenue in Chelsea with a balcony that faces east over the city; perfect for watching thunderstorms. The thunderstorm that has brought a bit of relief from the recent heat, came in strong and moved out fast last night, with the lightning visible to me first in the southwest and then seeming to move eastward around the island, finally disappearing uptown.  A hard rain fell just briefly on Manhattan in the middle of the storm, miring the clarity of the lightning and muffling the thunderclaps.

 

I’ve read that lightning strikes the Empire State Building around 100 times a year. It is a wonder that any structure can withstand being hit repeatedly with bolts that are temperatures hotter than the surface of the sun. That said, it has become clear to me over the years of watching thunderstorms rage around the city, that lightning does not always strike the tallest object in an area, in this case the Empire State Building, or even the top of the tallest object. How I made it so many years believing this myth I don’t know. Furthermore, lightning doesn’t always travel from cloud to ground, but often occurs inside a cloud or arcs from one cloud to another.

 

 Lightning over Manhattan. Photo by Sara Scrovronick.

 

I love being in the middle of electrical storms. All those shock waves and charges flying around me bring an energy and excitement that is unique and humbling. In this big city, the electrical storms are just about all that can dim the bright lights, even if only for a second.

 

(Sara Scovronick, who also took the photos, is Program Coordinator for the Center for Environmental Research and Conservation. CERC is a scientific consortium including  Columbia University, the American Museum of Natural History, the New York Botanical Garden, Wildlife Conservation Society, and Wildlife Trust. It is centered at Columbia University’s Earth Institute.)

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americanelm.jpg

By Erik Baard

The American Elm teaches us about how grandeur and delicacy, strength and vulnerability, can rise from the same roots. And how ubiquitous splendor can so suddenly become rare.

Step outside this weekend and watch these often supercentanarian monuments bringing forth delicate flowers, a pointillist expression. “They are small flowers that give an overall hue or yellowish orange and red across the whole tree instead of seeing individual flowers,” said Jessica Arcate, curator of woody plants at the New York Botanical Garden in the Bronx, which boasts specimens in natural habitat that pre-exist the institution’s 1891 founding.

“They weren’t planted there. They seeded in and grew naturally in the middle of our forest,” she said. “They like our flood plains, swales, run offs, and vernal pools.”

Calling their branch form “winged,” Arcate first fell in love with this largest species of elm while working on an estate in the Hudson River Valley. “They have such a full, almost weeping canopy. They’re just spectacular trees.”

The American elm in the NYBG photo above, taken March 26, can be found in the Benenson Ornamental Conifers collection. Arcate cautions that no photo can do them justice. Perhaps the words of Oliver Wendell Holmes, Sr. description of coming upon one over a hundred feet tall and in full leaf might help:

“…I saw a great green cloud swelling in the horizon, so vast, so symmetrical, of such Olympian majesty and imperial supremacy among the lesser forest growths, that my heart stopped short, then jumped at my ribs as a hunter springs at a five-barred gate, and I felt all through me, without need of uttering the words, ‘This is it!’”

Finding a large stand of American Elms is elation itself, and always a product of nature guided by human artifice. Central Park designers Frederick Law Olmstead and Calvert Vaux planted The Mall, best reached via the East 66th Street or East 72nd Street entrances, with four rows of American elms flanking the promenade. The flying buttresses of prodigious branches arc until they clasp in a vault of joyous green-gold in mid-spring’s leaf flush and by summer fill in to create a hushed enclosure of uncrowded communing. This is our city’s Great Nave.

Native Americans used the trees as landmarks for gatherings, and derived medicines for ailments ranging from coughs to obstetrics. European colonists also fell for them fast and hard. While much of the continent was still wooded, town elders had wild American elm saplings planted in the Boston Common. As the U.S. population boomed, American elms became a street tree of choice, lining both grand boulevards and sleepy suburban tracts that sprang up along railroad lines. Part of this preference stemmed from their hardiness, in terms of temperature range and native pests, including hundreds of insect species. Utility also played a role; the high arcing branches that give American elms their distinctive vase or umbrella shape shade streets while allowing traffic to pass.

Today the pleasure of spending time among American elms is a rare privilege by which light New Yorkers are spoiled. We have some of the world’s largest stands, notably in Central Park and Riverside Park. Though wild American elms were once most abundant in the eastern United States, they now survive in substantial numbers primarily in Midwest and Canadian prairies.

We descended to that sad state following the 1930 introduction of Dutch elm disease, a fungus that hitched aboard logs shipped from Europe. The vector for transmission is the European elm bark beetle.

“Borers tend to go to trees that are stressed out, so they went for the street trees first,” Arcate said. Healthy trees in the niche for which they have evolved deploy natural defenses that can thwart attacks that would fell street trees.

“There’s research indicating that some trees give off an infrared shade that changes when they’re sick. Insects flying around know it,” she said. Once set upon by the fungus, the decline and mass death was visible to human eyes. Trees yellowed and weakened in vast waves. Miles of American roads were left sun scorched in summer and hauntingly barren in winter. Communities were stripped of their sense of place.

Remaining urbanite American elms demand constant monitoring and intensive care from stewards like the New York Department of Parks and Recreation. Keeping them alive, however, is still cheaper than letting them die. Removing a dead American elm can cost in one shot as much as providing decades of care, to say nothing of adjacent property values. As Michael Pollan notes in a brilliant essay about species, their survival is a civic effort. In a sense, they have become our city’s arboreal humpback whales or polar bears, massive and strong yet begging for care after the damage we’ve introduced.

 

Efforts to hybridize or otherwise alter the American elm to resist the blight have shown progress, but the “holy grail” of an immune tree that perfectly retains the beloved form remains elusive.

But the battle isn’t entirely defensive — foresters are replanting thousands of American elms, hundreds by the Natural Resources Group of the NYC Parks alone, in recognition of its central ecological role.

As with what animal conservations call “charismatic megafauna,” saving the signature species can serve as a vehicle for broader ecological protection. Elms in the wild thrive when surrounded by dense associations of tree species, and special regional relationships have evolved. In New York you’ll often find American elms in the company of white ash, slippery elms, rock elms, yellow birch, black tupelo, sycamore, eastern hemlock, bur oak, swamp white oak, and silver maple.

American elm leaf litter decomposes into soil that unusually rich in soil-improving elements, including potassium and calcium, which as electrolytic minerals can eventually prove valuable for flood plain animals as well as undergrowths and ground covers. “We know amphibians are there. Groups comes to count the tadpoles,” Arcate said. In 2004, an Audubon Chicago study found that American elms were strongly preferred by migratory birds. Butterflies rely upon them for nectar and as a place for larvae to develop.

It’s hard to imagine, when standing before a single American elm, how many organisms have made a world for themselves from the vernal pools gathered at its roots to the “green cloud” above. Sadly, we need no imagination to conceive of the vacuum that would follow neglect.

  

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