Nature Notes: Changes in Vegetation

When the Laurentide ice sheet retreated and left Long Island in its wake, there were no humans residing here
Carissa Katz

Eastern Long Island owes much of its natural history to the eastern deciduous forest, an ecological life zone that stretches from the grasslands of the Midwest to the Atlantic Coast, from northern Florida into southeastern Canada. Of course, there are huge differences from one part of this forest zone to the next, and from the southern part to the most northern part.

When the Laurentide ice sheet retreated and left Long Island in its wake, there were no humans residing here. Then came a very gradual change, from bare land to a boreal, tundra-like vegetative covering such as we find around the Arctic Circle today. Next, the vegetation progressed to shrubs and small trees — willows, birches, and such — followed by what is popularly called the northern coniferous forest, with hemlocks, larch, and various spruce dominating. Spruce were still extant as late as 1923, when the late naturalist-farmer Roy Latham described a stand of them on the north side of Orient. 

There were hemlocks and several birch species still extant in the early 1900s, but as a result of further warming, they were replaced by oak and hickory woods, followed by pitch pine and hardwoods, covering that part of Long Island now dominated by the Pine Barrens. This succession from one vegetation type to another quite different, and so on and so on, took place over the course of 15,000 years,

The rest of the United States, excepting Alaska and Hawaii, is made up of prairies, deserts, mountains with montane vegetation zones from bottom to top, and a little tropical forest in southern Florida. Then there are a bunch of different wetland types like salt marsh, thule, swamps, bogs and the like, and a variety of ponds and lakes with subaquatic and floating aquatic vegetation.

America’s vegetation types are not unlike those in the rest of the Northern Hemisphere, but in general quite different from those in the Southern Hemisphere, where tropical forests dominate, except in those areas occupied by savanna grasslands and deserts, like the Kalahari Desert in Africa.

Before colonial settlements began sprouting up in the middle 1660s, Long Island had the Pine Barrens, large grasslands such as the Hempstead Plains, brushy savannas, beach and dune vegetation, and a large variety of wetland types — everything from extensive salt marshes to tiny wet depressions dominated by insectivorous plants and cranberries, such as those that still exist on Napeague and in Montauk.

Paleobotanists have studied the changes in vegetation by taking cores from deep boggy kettleholes. The pollen from the deepest part of the cores can be identified to tundra and taiga forest plants, the topmost pollen to the more southern hardwoods and pitch pines.

Take the tupelo, for instance. It is quite common on Long Island in wet areas, but it is the same tupelo species that grows in Tupelo, Miss., known more as the birthplace of Elvis Presley than for its tree species. The southern red oak has established in Montauk, there are a few southern magnolias in Nassau County, persimmons on Gardiner’s Island and in East Hampton’s Northwest, lots of sweet gums (Liquidambar) in Queens and Nassau. As global warming continues, expect that a lot more southern tree species such as live oaks will establish here.

Of course, there are lots of variants of major ecological types. The dwarf pine barrens in Westhampton, off County Road 31 near the airport, are stunted but genetically different versions of normal pitch pines. For the last three years, Victoria Bustamante, a local native-plant grower, has been watching a group of the dwarf kind growing in pots in her greenhouse in Southampton Village. They are definitely much smaller than neighboring normal pitch pines planted from pine nuts in pots at the same time and grown under identical conditions. It may have been these dwarf Westhampton pitch pines that George Washington referred to as “ill-thriven” during his turn-of-the-18th-century trip to Montauk to site the lighthouse.

There is a remnant white pine forest flourishing in Northwest. Indeed, it will probably benefit further from the recent invasion of the southern pine borer beetle, which has killed so many of East Hampton’s pitch pines. When you drive along Bull Path, for example, you see almost no small pitch pines, but an abundance of white pine saplings. The groundwater they root in is an almost constant 55 degrees Fahrenheit. and is evidently substituting for the normal cooler ambient air temperatures in more northern regions where white pines grow in profusion, such as in Maine and northwestern Massachusetts.

Broadly speaking, there are a great many types of plant communities in East Hampton. One community that is also found on Block Island, Nantucket Island, and southeastern Massachusetts and Rhode Island, but is absent from the rest of the United States and Long Island, is “heathland,” dominated by shads, American holly, witch hazel, and shrubs of several different ericaceous species, as well as many different ferns. It is as thick to walk through as any tropical forest I’ve experienced.

There are lots of dune plants and grassland plants, as in the Montauk grasslands east of Lake Montauk, which in the early 1900s covered three-quarters of Montauk, including much of Hither Woods. The federally protected sandplain gerardia, rediscovered growing at Shadmoor in 1982, is just one of many native prairie species found in Montauk, along with the state-protected bushy rockrose, Helianthemum dumosum.

When “The Botany of Montauk” was written by Norman Taylor in 1923, there was only a handful of houses in that hamlet, as well as only a handful of exotic species. Now Montauk has as many Eurasian species as metropolitan New York, so many that the several rare species there are threatened with extinction by competition with the weedy species, including even that horrible invasive vine from Asia, kudzu. Such half-and-half habitats are now called “novel” ecotypes, for want of a more descriptive name.

In summary, the South Fork has several different plant habitats, including white pine forests, pitch pine-oak forests, deciduous hardwood forests, grasslands, shrub-savannas, and dune and beach vegetation zones, as well as a bunch of ecotonal combinations where two or more different types come into contact with each other. In addition, there are at least 10 different wetland vegetation types, including some dominated by myriophyllum and other interlopers, such that they are now in the “novel” ecotype category.

The central pitch pine maritime forest, now mostly protected, in Brookhaven, Riverhead, and western Southampton, is one of the jewels. The same pitch pine maritime forest type, during the last half of the 20th century, has reached the middle of the Napeague isthmus, and even reached the Walking Dunes of extreme western Montauk. Shortly after, the Central Pine Barrens Maritime Forest Preserve was created by an act of the New York State Legislature and signed into law by Gov. Mario Cuomo.

At the beginning of the 21st century there was an effort by the Group for the South Fork and the South Fork Groundwater Task Force to add these eastern South Fork pinelands to the already preserved central area, but the two towns — East Hampton, under the leadership of Supervisor Jay Schneiderman, and Southampton, led by Supervisor Pat Heaney — stifled it. As a result, these eastern pinelands have languished in never-never land ever since. Perhaps it is fitting, then, that the southern pine borer beetle is having the last word.


Larry Penny can be reached via email at Larrypenny9@gmail.com.