Diversity Is Where You Find It
Does a natural place really have to be 100 percent natural? Few of them are. Even if some woodland in New Jersey has not been cleared within living memory, and may appear "unspoiled," you can be sure that it has been invaded by introduced plants, assaulted by foreign insects, and affected by man-induced changes in air and water quality. Sure, it's nice to stand among ancient oaks in the Great Swamp or to savor the shelter of a white cedar stand in the Pine Barrens, and to imagine that it looks as it looked a millennium ago. But what most of us "nature" people are looking for, most of the time, is natural diversity. And maybe we make the assumption (whether we realize it or not) that maximum diversity of birds, or plants, or insects, or whatever it is we seek from the out-of-doors is to be found in aesthetically pleasing places that have been little disturbed by man.
This is not always true. There are some relatively undisturbed habitats in New Jersey -- including parts of the Pine Barrens, and some kinds of wetlands, and ridge tops in the Highlands -- that are notoriously low in species diversity. They may be pretty, but they are simply difficult places for plants and animals to colonize. And there are some highly disturbed, sometimes unlikely places, that are surprisingly varied in their flora, if not their avifauna. A Torrey Botanical trip a few years ago found 105 species of plants (and some rather odd ones at that) in sidewalk cracks and vacant lots in about half a mile of Manhattan's west side. And as Aldo Leopold said (and if you don't know who he was you should find out): "The weeds in a city lot convey the same lessons as the redwoods."
Consider Liberty State Park, for instance. Located in densely populated and almost completely built-up Hudson county, and surrounded by development except where it fronts on Upper New York Bay, it seems like a highly unlikely place for any kind of rewarding nature study. Even the land here is unnatural -- almost everything east of the turnpike was created (mostly during the mid-nineteenth century, but continuing to the present day) by filling tidal marshes with garbage, dredge spoil, and especially ship's ballast (sand, earth, and other low-value but weighty materials carried by sailing vessels to ensure stability at sea).
But even as many of our own ancestors were arriving in America at Ellis Island just offshore, the ancestors of many of our most familiar plants were also getting a toe hold in the New World, where Liberty State Park is today, for the mostly European soil used to fill the marshes contained seeds of European plants. Along with seeds that came in on bulk cargo in this precontainer age, and seeds of western and southern plants that were transported by the railroad or came in with barge traffic on the Morris Canal (which ended here at Communipaw), the European seeds germinated to create a highly varied, if rather exotic, flora on this northern Jersey shore.
For a while, in fact, these "ballast dumps of Communipaw" were a happy hunting ground for botanists from New York City, and over a hundred species were added to New Jersey's plant list as a result. Several scholarly articles were written about the site. But most of the plants soon died out and many have not been seen since on this side of the water. Wimp plants! Others, however, the tough ones that could survive cold and cutting and smog and dirt and poor soil, managed to survive. The old lists include plants like cat's-ear, prickly lettuce, alsike clover, coltsfoot, and ivy-leaved morning glory that are pretty ubiquitous roadside and vacant-lot plants today.
Nobody at the time seems to have paid much attention to the birds of the area. It was wooded. One may assume that the abundant waterfowl that can be seen in Upper New York Bay today were even more abundant then. Certainly, the site is on a promontory between two bodies of water (New York Bay and Newark Bay) in much the same way that Cape May is a promontory between the Atlantic Ocean and Delaware Bay, and it is on a flyway, so one can assume that the birds were numerous and varied, that warbler waves and autumn hawk flights were spectacular. The Hackensack marshes, just north and west of the area, were famous for their variety of bird life.
Eventually, much of the filled land was used by the Central Railroad of New Jersey as a major terminal. But rail traffic diminished in the 1950s, with the perfection of tuck travel as a preferred means of bulk transport. Passenger traffic slowed as commuter busses and private cars took advantage of bridges and tunnels built in the 1930s and 1940s. Pier facilities became obsolete, and railroad-related activities declined. The state of New Jersey acquired the land, piecemeal, between 1970 and 1975. One of the first projects undertaken by the state was a systematic clearing of railroad tracks, dumps, abandoned industrial buildings, and the like, which incidentally denuded the site of much of its vegetation. Aerial photos taken after the cleanup show little green.
But what is it like today? Well, in open fields the once-bare earth has been covered by vegetation, with the expected variety of goldenrods, mugworts, and other members of the aster family (fifty-seven species of them, in fact); grasses (forty-eight species); mustards (fifteen species); and legumes (fifteen species). A large part of the park is undeveloped and in fact is not open to the public, but many of the interesting plants (and birds) can easily be seen from the park roads. In places, cottonwood, gray birch, American elder, black cherry, Ailanthus, and dwarf sumac create shrub thickets that make fine shelter for migrant landbirds, spring and fall. There are numerous small wet pockets, which sprout purple loosestrife, phragmites, broad-leaved cattail, and knotweeds in profusion. There is a salt marsh -- not a very big one, but a typical one -- that is accessible to the public. Plantings of autumn-olive, bayberry, beach plum, cockspur hawthorn, black chokeberry, and Japanese black pine complete a picture of an industrial area gone to green. Actually, a 1988 study turned up 331 species of plants growing without cultivation here -- which is about the same number of plants that can be found at Cape May Point State Park (which is very much smaller) or at Island Beach State Park (which is much larger).
Overall, about 25 percent of the plants recorded in New Jersey are alien species that have naturalized themselves, but at Liberty State Park nearly half the plants are alien, mostly European species, including such familiar plants as dandelion, chicory, and Queen Anne's lace, but also three species (the grasses Calamagrostis epieious and Apera interrupta, and a resinous yellow-flowered composite, Dittrichia graveolens, that boasts the inelegant name of Stink Aster) that have never been found in New Jersey before!
In addition to the European plants, some of which may have persisted here since their introduction in ships' ballast over a century ago, several western and southern plants can still be found in the botanical melting pot that is Liberty State Park. Again, these range from familiar plants like sunflower and cottonweed to comparative rarities like bracted vervain (Verbena bracteata), hoary vervain (Verbena stricta), Torrey's rush (Juncus torreyi) and clammyweed (Polanisia graveolens.) Not everything at Liberty State Park is "weedy," however; among the truly native plants are the showy New England aster, the delicate nodding ladies'-tresses (the park's only orchid), and the spectacular swamp rose-mallow.
Of course, all birders know (or should know) that Liberty State Park is an excellent birding spot, particularly in winter and particularly for unusual gulls and owls (including snowy owl, which turns up here almost every winter). William Boyle, in his Guide to Bird Finding in New Jersey, mentions red-necked grebe; great cormorant; Eurasian wigeon; lesser golden plover; little, common black-headed, Iceland, and glaucous gulls; all three scoters; northern harrier; short-eared owl; purple sandpiper; clapper rail; horned lark; snow bunting; and white-crowned and Lincoln's sparrows in his description of the park's bird life. The park list is over 200 species. Particularly good spots are the dense plantings that have been made south of the Environmental Interpretative Center; the salt marsh; tidal mudflats south of the park, that can easily be viewed from the parking area; and a small freshwater pond north of the Environmental Interpretative Center.
Liberty State Park is visited by two million people a year, and hardly any of them give thought to the potential of the site as a place to study nature. Nature, if they think of it at all, is something that only exists outside of New Jersey. But consider: here's 1,100 acres of public land, on a flyway, that has old fields, shrub thickets, a salt marsh, sheltered saltwater coves, a highly unusual and very diverse flora, a one-of-a-kind view (hey, lots of places have mountains and waterfalls, but there's only one New York skyline and one Statue of Liberty, even if she does have her back turned to the park). There are no dangerous mammals (lots of rabbits, though, and maybe a fox or two). It's right off Exit 14-B on the turnpike. There's plenty of parking and public rest rooms. There's no admission fee. And the diner up the road has good coffee and cheesecake. So what are you waiting for?
Reprinted from NJ Audubon magazine, Spring 1989.