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Archive for March, 2008

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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American Woodcock in Propsect Park by Steve Nanz.

By Erik Baard

In recent weeks keen-eyed birders have each night spotted the quiet and nearly invisible migratory returns, solitary or in very small flocks, of one of New York City’s quirkiest birds.

While some birds, like redtail hawks and peregrine falcons, have attracted groupies through intelligence and fierce dignity, today we present a species that’s won the hearts of hardened New Yorkers through its ostentatious goofiness, the American Woodcock.

If you manage to spot one despite its exquisite cinnamon, gray, beige, and pale orange camouflage in the leaf litter, you’ll note its extraordinarily gawky four-inch bill, more than a quarter the length of its seemingly no-necked, stout body. Then it’s on to the high-crested, buggy eyes set behind its ear holes. To make that odd arrangement of features work, its brain is uniquely positioned: upside down, with the cerebellum resting above the spinal column.

“Back on January 21, 2003, I was shocked to see one on the sidewalk at 18th Street and Park Avenue South. It was probably killed when it flew into a window,” recalled artist and outdoorsman Steve Sanford. “There was a postal delivery guy just standing over it for a long time, wondering what it was, it looked so strange to him.”

And of course, its name is tailor made for preadolescent snickering and email spam filtering. A host of alternate names sound a bit like party drinks: timberdoodle, bog sucker, mud bat, mud snipe, and Labrador twister.

That latter name, however, hints at why their devotees are now clearing their schedules of after work commitments and redirecting their morning jogs to mucky corners of parks. The woodcock’s spiraling mating display, an aerial dance at dusk and dawn, is a signature of Spring that delights the eyes and ears.

“Some of these birds who wintered in southern states are passing through,” said NYC Audubon President Peter Mott, referring to New York City’s place on the eastern seaboard’s migratory flyway. “Those that are staying are setting up their courtship territories. In just a week from now they should be starting their courtship flights.”

You’ll need to visit a wooded area edging a fresh water body and a small clearing. Two places Mott recommends are the Ramble in Central Park (a section called “The Oven,” near the boathouse), and the East Pond of the Jamaica Bay Wildlife Refuge, which is also a favorite spot for the tireless Brooklyn Bird Club. Other places known for woodcocks include Pelham Bay Park and Givans Creek Woods Park in the Bronx, the Staten Island Greenbelt,  and Prospect Park in Brooklyn, where the photo above was taken by Steve Nanz (click to enlarge).

Where males have formed a loose gathering, called a lek, individuals bob and rotate on the ground in twilight hours, making a peent sound before suddenly jumping into flight. They ascend steeply in a spiral up well over 100 feet, “making a chirping sound with their wings. Then they’ll plummet to earth and hope a female was watching.”

While the males’ ground call is utterly prosaic, the twittering sound made by air passing through specialized feathers of their fast-beating, rounded wings is soothing. The downward glide is accompanied by a vocalization that naturalist Aldo Leopold called a “soft liquid warble.” Marj Rines has audio samples on her great website.

Still, overall it’s a pattern familiar to anyone who’s ever observed a “Sk8ter Boi”: call attention, perform a trick, hope it was witnessed by a pretty girl.

Such acrobatic displays demonstrate vigor, and to produce pleasing wing song a woodcock must be ideally formed with a span fringed with three very fine feathers – a sonic flaunting of symmetry – that advertises genetic viability for robust offspring. A strong start is critical for hatchlings that are nearly independent soon after emergence, reaching adult form in weeks.

The woodcock’s odd face is no less a product of ruthless natural selection than a lion’s fangs. Those oddly set eyes provide nearly 360-degree vision. The woodcock beak is not only long, but articulated and sensitive toward the tip, so that it can probe the mud more effectively for worms and other invertebrates; they can eat their weight, about 10 ounces, daily. Put those two features together and you have a bird that can watch for predators above while simultaneously feasting on what’s below.

The transitional forest ecosystems for which the woodcock has evolved are equally refined, but have been challenged in recent decades. Most conservationists believe this is what accounts for the species’ 55% drop in population since 1960. Poorly-conceived development is a huge problem, of course, but another factor might surprise you. Our attentive forest managers have prevented many forest fires, blights, and other natural means of tree felling, denying the woodcock clearings for mating displays. Clearings also allow for new growth like meadow, understory plants, and a dense covering of saplings to provide resting protection from owls.

When Mott was asked which of these unique characteristics made him so fond of the woodcock, he said his pleasure was in the sharing. “I enjoy taking people to see them,” he said. Funny how a bird that leads a relatively solitary life can bring us together.

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By Erik Baard

Easter eggs are hunted in “Eggstravaganzas” and “Eggstreme” events across the city, from the Bronx Zoo to the Queens Zoo, and south to the Leon Kaiser Playground in Brooklyn and the West Brighton Zoo on Staten Island. But the best-hidden eggs in the very center of Gotham right now may be those laid by Winter Flounder.

The mighty machinery of our industrial port city has been stayed so that the roughly million tiny eggs (the fertilized flounder eggs magnified in the photo above are from a Virginia Institute of Technology laboratory) dropped by each mature female can be deposited right on the sandy substrate, and incubate undisturbed for two or three weeks.

“From February first through the end of May for the past several years we’ve suspended dredging the shipping channels where the eggs are laid,” said William Slezak, Chief of the Harbor Operations Branch of the U.S. Army Corps of engineers. Winter flounder prefer sheltered shallows with cool water, such as you’ll find in the kills (Dutch for creek, a linguistic colonial legacy) surrounding Staten Island, Newark Bay (a main commercial hub of the mid-Atlantic region), Jamaica Bay, and Raritan Bay.

That surprising deference to a not-so-pretty bottom feeder reflects not only how far natural resources public policy has come hereabouts, but how dire the winter flounder crisis has become.

“It’s pretty amazing that winter flounder is steering dredging policy in the harbor these days. These ‘conservation windows’ are certainly very progressive, working our way around a species’ critical periods to cause as little harm as possible,” said Queens College marine biologist John Waldman, author of Heartbeats in the Muck. “But something has happened and the local stock is really crashing.”

Waldman, who grew up on the western Long Island Sound, recalls that in his youth the species was “common as hell.” Now, after a decline in population that began in the ‘70s, “You can fish all day and catch one or two.”

Waldman points to a pincer of culprits threatening the species: global climate change and “a whole suite of hungry mouths.”

The species is clearly sensitive to warmth; when water temperatures cross 73 degrees Fahrenheit (23C) they bury themselves in muddy bottoms and wait out the heat wave. A few degrees more and they are dead. Also, as Waldman pointed out, a change in water temperatures could disrupt previously reliable detritus-based food production at the microbial level before it can rain down to the flounders below.

As for all those “hungry mouths,” winter flounder certainly remain prized by local anglers, including those in New Jersey ready at this very moment to sneak out from family gatherings to hook them; fishing season for the species begins today. But natural predators, often themselves benefitting from government protection, are removing much more winter flounder, both in terms of numbers and biomass. Species like striped bass, bluefish, summer flounder and fluke, and even seals in the Gateway National Recreation Area, are feasting on winter flounder. Cormorants are a new arrival to our estuary, having expanded their range north. These extraordinarily effective fishing birds put greater pressure on an already stretched resource.

But there’s some cause for optimism about the estuary as a whole, even if winter flounder fans aren’t ready to pop the cork on the champagne. The National Oceanic and Atmospheric Administration section for Ecological Applications views the species as a maritime canary in a coal mine, signaling befouled habitats in decades past. Note this report based on data from decades past:

Winter flounder are particularly susceptible to pollution (Grosslein and Azarovitz 1982). The eggs are laid directly on the substrate and therefore any toxins in the sediment can affect their viability. This species’ close association with the benthos also potentially exposes the fish to sediment toxins. Grosslein and Azarovitz (1982) noted that few larvae survived in polluted estuaries, and that winter flounder were entirely absent from polluted sections of NY/NJ Harbor. In particular, winter flounder experience increased mortality as a result of exposure to insecticides, especially DDT (Buckley 1989).

But now, while winter flounders are scarcer than ever, their re-colonization of our bays and inlets testifies to a cleaner and healthier estuary.

“It’s interesting, a kind if dualistic situation. The Upper Bay and some of these other places in the harbor were once written off as wastelands, and now they’ve recovered so much that they are recognized as productive ecosystems,” Waldman observed. “So in a way, there’s some good news here.”

Yeah, but just try to get a flounder to see any situation from both sides.

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By Erik Baard

This Easter weekend you expect to see an energetic, toothsome creature energetically digging for carrots. You just don’t expect him to be a guy named Steve, or that one of his favorite patches is in Manhattan.

Wildman Steve Brill” is a self-described forager who leads tasting tours of urban parks, and publishes guides and wild plant cookbooks. Indeed, he was arrested once on orders of then-NYC Department of Parks and Recreation Henry Stern for “eating my parks.” Brill has since made peace with the authorities.

The ancestor of agricultural carrots, pale purple-white like the inside of a clamshell, enthralls him. “They’re delicious, and make great cakes, cookies, and soups. And they hold together a lot better than commercial carrots,” he enthused. Eat them early in their lives; the long, edible taproot soon becomes woody and tough.

But might they be, counter-intuitively, less nutritious than mass-market varieties? After all, the wan root (shown above in a photo by Steve Brill) lacks the orange flare we associate with beta-carotene. Actually, the original strains are also nutrient rich.

The wild carrot, part of the Apiaceae family, is also known as Queens Anne’s Lace and Bishop’s Lace for its fine, biennial flowers that bloom in summer, to the delight of butterflies. But it’s not as fussy as those monikers might imply. “They thrive in sandy, overgrown areas,” Brill noted. As with all things in New York, the key to a worthwhile gathering of wild carrots is location.

Brill remembers his first, uninformed, sampling. “I was quite disappointed. I was using field guides by botanists who wouldn’t know a kitchen if it fell on their heads,” he recalled. “The carrots were as small as the graphite in a pencil.”

Two places where populations of this Old World invasive, but widely tolerated and still cultivated, plant are robust enough to satisfy Brill’s discerning palate and hearty appetite are Manhattan’s Central Park and Inwood Hill Park. A few other places where naturalists have noted Queens Anne’s Lace include Kissena Park in Queens, Prospect Park in Brooklyn (and its flowers have even been spotted poking out of a chain link fence near the Atlantic Yards), and along the waterfront of Staten Island. Some good nearby suburban spots for wild carrots include Westchester’s Untermeyer Park and Tibbets Brook Park, and Liberty State Park in Jersey City, New Jersey.

Just keep your eagerness in check or you might face a greater hazard than Peter Rabbit did in Mr. McGregor’s garden. “That plant has a deadly look-alike, water hemlock,” Brill warned.

So please, stay among us for a while longer by paying due caution; losing Socrates was enough. Besides, the Wild Carrot Society sounds like it would be a lot more fun to join than the Hemlock Society. Make sure you go first with an experienced plant scientist or naturalist, and keep this check list of distinguishing features in mind: bi-pinnate and tri-pinnate leaves, steams and leaves covered with fine hairs, and a root that smells like a carrot. Another reassuring sign can be a red flower at the center of its pale bunches.

Others, recognizing the unusual chemical properties of Queens Anne’s Lace have investigated its use in folk medicine as a contraceptive. That’s an application that exceeds the wildness of public park tours, even when led by “Wildman Steve Brill.”

And now we hope find wholesome motivation to go a-digging by perusing a few recipes from the quirky Brits at the Carrot Museum.

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by Erik Baard

If Nature Calendar holds any value, it will be measured by how much it nurtures the feeling that your life is woven into a whole, a kinship that won’t be walled within a name. May I then call you to witness, this first weekend of spring, the birth of suns and worlds and seas?

Tonight, turn away from the busy glare of dutiful streetlamps and hurtling headlights. Climb the stairs to the roof, crawl out onto the fire escape, or stroll into the open green of a park and look to the southern sky for square-shouldered Orion. Better yet, join the star party hosted by the Amateur Astronomers Association of New York at Great Kills Gateway National Park, next Saturday, April 12.

But quietly defy millennia of tradition and see before you not a mythological hunter, but a mother.

“For many years I’ve thought the Greeks got it wrong,” said astrophysicist Mordecai-Mark Mac Low, who uses supercomputers to simulate and study stellar evolution in nebulae at the American Museum of Natural History. “If she’s giving birth to stars below her belt, Orion’s a woman.”

The Orion Nebula (a faint smudge of light reaching us across 1,600 light years of space but seen in the photo above with the Hubble Space Telescope‘s crystal clarity) had been imagined to be the center of the constellation’s sword. In fact, the Orion Complex, composed of the nebula and billowing gases and dust behind it, doesn’t resemble the clean lines of a blade so much as the hazy shape of an ultrasound, and for good reason. You’re gazing into a cosmic cloud womb.

Planetary scientist David Grinspoon also dismissed Orion’s “macho hunter dude” image and asserted, “That stellar womb has the right placental nutrients to create life. As sure as I can be about anything without direct empirical evidence, I am sure that’s where our star brethren are being born.” Grinspoon is the astrobiology curator of the Denver Museum of Nature and Science and author of Lonely Planets: A Natural Philosophy of Alien Life. He is also the interdisciplinary scientist of the European Space Agency’s ongoing Venus Express mission and a lead investigator for a radiological instrument on a coming NASA rover mission to Mars.

Our closer stellar family, from the sun to the far-flung tumble of ice worlds and comets and sister stars, may have been born in just such a place 4.65 billion years ago.

“It’s almost like a view to our own origins, and it’s happening all over the universe. Because it’s so close and we have such a good view, the Orion Nebula gives us a wonderful chance to peer outward and at the same time feel like we’re peering backward and peering inward,” Grinspoon said.

Mac Low agreed. “That’s an increasingly well supported idea,” he said.

Natural philosophers Immanuel Kant and Herbert Spencer intuited the “Nebular Hypothesis,” that there was a seamless evolution from dust to intelligence. Scientists now recognize that it’s quite a rough and uncertain ride over that arc, but the beauty and utility of that vision endures and instructs.

The Orion nebula, visible to the naked eye and lovely through binoculars or a telescope, is a scrim of hot, ionized gases blown about by the jets, shock waves, and ejected “wind” of stars birthing, churning, and dying. It twists into, and partially obscures, a trillion-mile wide molecular cloud containing hydrogen, oxygen, nitrogen, carbon, silicon, iron, and hundreds of compounds including organic substances like ammonia and methane. It’s a deep space ecology, of sorts.

Much of the material is collapsing under gravity to form new stars. The youngest and brightest of them is estimated to be a mere 10,000 years old. When it ignited, the artist from Germany’s Aurignacian culture who carved an apparent Orion star map and pregnancy chart into a sliver of mammoth tusk was already dead for over 20,000 years. Contemporaries of that star birth might have wished they could feel some of that new heat. In what would become New York City, villagers were then huddled between the foot of a receding ice sheet and rising seas.

Other juvenile stars are accreting protoplanetary discs. So far astronomers have counted what appear to be 2,300 of them in the Orion Complex, using the Spitzer Space Telescope. Heavier elements in the dust are fossils of ancestral stars that synthesized them in their increasingly strained, aging fusion generator cores before catastrophic deaths. Not only does the grittier stuff coalesce to form rocky worlds, but by shading hydrogen and oxygen from energetic ultraviolet light, it allows water to form.

According to readings from an infrared space telescope survey, the Orion cloud complex is producing water at a daily rate that would fill all of Earth’s oceans 60-times over, and already contains a million times more water than our planet. Casting our vision billions of years forward, fantasies can readily conjure a great harbor city showing as a beacon on the night side of a “lonely planet,” in a dark region of space where the Orion Nebula has long been consumed away.

How precious our moment is, a time when carbon, hydrogen, and oxygen have been formed into our brains and sensitive fingertips, to enjoy caressing striations carved into Central Park’s exposed silicate bedrock by glaciers of hydrogen and oxygen.

We are a single pulse in the body of what my murdered friend, science maverick Eugene Mallove, celebrated as The Quickening Universe.

May we at Nature Calendar never fail to remind you that this single cosmic pulse is your season to bloom.

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