Places that Matter

Inwood Hill Park

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Amelanchier canadensis, aka shadbush, so called because it's flowering usually coincides with migrations of the shad fish, 2012
Amelanchier canadensis, aka shadbush, so called because it's flowering usually coincides with migrations of the shad fish, 2012
Inwood Hill Park
Spicebush, 2012
Oak Apple Gall, 2012
Salt Marsh at Inwood Hill Park, 2012
Inwood Hill Park
Marielle Anzelone shares stories about the plants in Inwood Hill Park, 2012
Large and beautiful park along the Hudson offering NYC's last natural forest and the Urban Ecology Center
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Inwood Hill Park offers an enduring glimpse of Manhattan’s ancient past. Its valleys, boulders and ridges were molded by glaciers fifty thousand years ago. Its close-to-200 acres contain remnants of Manhattan’s original forest and, along the edge of the Harlem River, its only surviving natural salt marsh.

The Wiechquaesgeck Indians frequented this place, camping for the summer in its hillside caves so that they could fish in the waters of the Harlem and Hudson rivers.  Close to the caves–at the southwest corner of the ball field at 214th Street–a boulder called the Shorakopoch Rock marks the spot where Peter Minuit in 1626 purportedly bought Manhattan Island from the Indians “for trinkets and beads then worth about 60 guilders.” (Modern scholars are inclined to place the deal downtown, at the Battery.) In the 17th and 18th centuries some of the land was settled by European colonists, and a Revolutionary War-era fort stood in the northwestern corner of the park.  Scattered around in the underbrush there are fragments of wall where lavish 19th-century estates (including that of Samuel Lord of Lord & Taylor), a women’s home, and a public library once stood.  They were all razed after 1916, when the city started buying up the land. The park was officially opened on May 8, 1926 and work continued on it through the Depression, when WPA workers built roads and trails.

The forest trees are alive with birds, year-round residents and migrating travelers, including bald eagles. From the cliffs at the northwestern end, you can gaze at views of the Hudson and the Palisades that Native Americans and colonists saw centuries ago.

In the twenty-first century, New York City-based ecologist Marielle Anzelone visits Inwood Hill Park frequently. Formerly a city botanist with the Department of Parks and Recreation, Anzelone has spent years working to conserve and restore New York City's natural areas. But she says that her profession still confuses people. "At cocktail parties people ask me, 'Oh, what do you do?' and I say, 'I'm a botanist.' And they say, 'Fantastic! Where?' and I say, 'Here. In New York City.' And people don't really know how to respond. But New York City has so much nature! The response is just a function of too few people talking about it. And in terms of plants, people talk about the Endangered Species List for species that are endangered nationally, but I like to look at it from a local perspective. We need to talk more about what local rarity means to the security of places in New York City."

True to her word, Anzelone is a serious proponent of talking about plants, and she has a special gift for telling stories that make plants relatable to the uninitiated. "It's really just that it's hard to talk about nature in way that's accessible. Most people don't have the tools to know or tell plant stories. But something like one-eighth of New York City is nature. That's more than any other city in North America. It's just not part of the iconography of the city. When you think about New York you think of hard-scapes and humans."

For Anzelone, and for many others, the forest is the jewel of Inwood Hill Park. Peaceful and undeveloped for centuries, the park's forest is now a city-owned nature preserve. It contains a rich mix of trees: hickory, hackberry, yellow poplar, birch and sweetgum, just to name a few. During an early spring walk in 2012, Anzelone identifies spicebush growing alongside one of the designated walking trails. Spicebush is a tree in the Lauraceae family, which also includes aromatic plants like cinnamon, an exotic, and sassafras, which is native to New York City and can also be found in Inwood Hill Park. Indeed, Native Americans used spicebush twigs as chewing gum. "Take the leaves and squish them up," she directs. "Smell! The smell is to ward off herbivores like deer that don't eat things that smell like that." Humans like it, but in nature, the smell acts as a repellent.

Spicebush is native to New York City, but it contributes positively to the park's biodiversity. "New York City sits on the Atlantic Flyway, so we're part of a lot of larger ecological migrations. Migratory birds, or, for example, monarch butterflies - this is one of three zones in the United States that they travel through. New York City is a major stop for both of them." During migration, birds stop and eat the berries that are left over from last year. They also eat the insects that are out in early spring, like caterpillars of spicebush swallowtail, a type of butterfly. Spicebush and related sassafras are critical foods for this butterfly.

Spicebush swallowtails begin life as caterpillars, which eat leaves. But spicebush, like other plants, doesn't want to be eaten. It produces the spicy aroma as a foil for large herbivores, and for smaller organisms like caterpillars (which don't have a sense of smell), the plant has a different biochemical shield embedded in its leaves. Anzelone compares it to tannic acid in oak trees. "Tannic acid in leaves and other parts of the tree increases over time. When the oak leaves first emerge in spring, they have almost no tannic acid. So it's a great time for caterpillars to eat them. But as the tannic acid increases, the caterpillars don't like it, and that's what it's there for, to ward off the caterpillars and other things that might eat the leaves." However, caterpillars can feed on the leaves long enough to serve as a viable food source for migratory birds that come through New York City. 

Lilac, whose seeds originally come from Asia, is an ecological import. Lilac has not been in New York long enough to form an evolutionary relationship with insects that would, in turn, be eaten by birds. "Lilacs are beautiful," Anzelone admits, "but they're like styrofoam. You find these things in the landscape that look and smell like plants to us. But for animals around them, they don't act like plants. They might as well be statues."

Inwood Hill Park contains many non-native trees, some of which were introduced by birds or other animal carriers. The eponymous "wineberry" was introduced to the United States in the 1890s. It is an invasive raspberry vine used to make wine, but it is a vigorous grower that can form dense thickets and displace native plants in the process. Others, like copper beeches, were planted by colonists centuries ago and have flourished ever since. 

Of course, Inwood Hill Park is full of native trees, like various oak species, which produce the whimsical oak apple gall. "You can see the exit hole," Anzelone says. "There's a class of parasitoid wasp that lay their eggs in the leaf of an oak. And in response to that biochemistry, the oak creates a ball around the eggs. Once the larvae are adults, they bite their way out." The gall is actually a mutated leaf, and in this state it is paper-light and delicate.

Tulip trees are among the easiest native trees to identify, thanks to their rod-straight posture. Most plants have positive phototropism, which means that they seek sunlight. If it's shady in the forest, they looks for holes in the forest canopy and they bend to grow toward the sunny spots. According to Anzelone, "tulip trees never do that. They say, 'I know the sun is up there. I'm just goin' up! So they grow very, very straight, and the Native Americans who lived here used them for canoes." In a few weeks these trees will blossom with tulip-shaped flowers, beautifully banded orange at the bottom, white in the center and green around the top. 

The Inwood Hill Park Urban Ecology Center opened in 1995, and Urban Park Rangers provide information and work with students on park restoration. But Anzelone acknowledges that there are still relatively few advocates for the rich histories of New York City's natural areas. She is trying to break that barrier by creating the Environmental Science equivalent of "that magical moment in the Wizard of Oz when everything changes from black and white to Technicolor." With the advantage of settings like Inwood Hill Park, she may well succeed. 

Anzelone adds, "It's not just, 'Oh, there's a tree, let's go hug it.' We're beyond that point now. And there's just so much research that shows that being in nature should be a public health mandate. Research shows that it's really good for people to be in nature, even in really dire circumstances. And we're talking about cities, the product of which should be happiness, right? That's what they say about the happiness index. People used to laugh about that, but it's real." 

This is particularly true as people are increasingly able to choose where they live. As we make decisions about where to raise families and establish roots, we should be concerned about how municipalities approach natural areas and local flora, whose healthy roots serve to reinforce our own.