Wednesday, March 05, 2003

Woodland (II)

Yesterday I revisited William Cronon's ecological history of New England, Changes in the Land, and — borrowing some additional ideas from the mammalogist Tim Flannery — examined Cronon's argument that the state of the “primeval” forest encountered by the first European settlers in the Northeast was in fact the end-result of a long process of co-evolution in which plants, animals, and Native American hunters and agriculturalists were all actors. Before the peopling of the continent some 12,000 years ago or so, the North American landscape had been shaped by an assemblage of large grazers and browsers, mostly now extinct, including giant sloths, mammoths and mastodons, and a larger version of the bison. The large herbivores kept the growth of vegetation in check, promoting relatively open woodlands and the proliferation of “edge” environments, and their extirpation, possibly by hunting, would have prompted an increase in forest density as well as a loss of habitat diversity. When the Europeans arrived, however, they commented on the open, “parklike” appearance of the southern New England forests, for by then the Native Americans, in order to encourage the population of species useful for hunting and foraging, had learned to reshape the woodland to their own purposes through the widespread setting of fires. The deep aboriginal Northeastern woodlands, seem, at least in southern New England, to be a myth.

Some parallel ideas emerge in a New York Review of Books article (as it happens, written by the same Tim Flannery) that includes a review of a new book by Franciscus Wilhelmus Maria Vera with the title of Grazing Ecology and Forest History. In Flannery's summary:
In our childhood, we all heard fairy tales about the European wild wood, which is portrayed as a gloomy wilderness where column-like trunks soar above the dank, entangled forest floor. But Vera argues that, except on some mountains, such forests never existed in Europe. Instead they are the invention of the foresters and ecologists of the nineteenth and twentieth centuries, who both created the first such forests by excluding grazing animals from forestry reserves, and spread the myth that the forests were somehow natural. […]

In Roman times, Vera points out, northern Europe abounded with great mammals such as aurochs, bison, tarpan, and elk, whose grazing prevented the forest from becoming dense and continuous. Many plants in the underbrush had evolved spines and thorns to protect themselves from the browsers and grazers, and it was these thorny plants that acted as protective nurseries for trees such as oaks. Outside their defensive palisades the forest was reduced to meadow, and so a woodland mosaic resulted. It was, Vera argues, a vegetation pattern that survived well into medieval times, for domesticated cattle, horses, and wild pigs continued to act as their wild ancestors did, both in creating meadows and in perpetuating the oak woodlands.

It has long been argued that Europe's greatest biodiversity is found not in its forests but in environments modified by human beings. Richest of all is the oak forest, a woodland environment that has long been thought of as resulting from the introduction of grazing herds into the primeval forests in medieval times. Vera argues instead that the oak forest is a relic of a pre-agricultural Europe, and thus it is the true primeval European environment. The only change, he contends, was that the herds of grazing animals that maintained it became domesticated, a development which did not substantially affect its structure.

Vera thinks that belief in the existence of the illusory primeval European forest is leading to environmental catastrophe. The last remnants of oak forests are being choked to death by trees because, in an effort to return them to what the environmentalists see as “nature,” grazing by domestic stock has recently been prohibited in them.
The idea of the “primeval” European forest is a powerful presence in our folklore and literature. (Also, more disturbingly, in our national mythology: see Simon Schama's Landscape and Memory for some interesting material on the role of the myth of the forest in virulent forms of German nationalism.) One biography of the Brothers Grimm is entitled, fittingly, Paths Through the Forest. But were the looming woods of folklore ever a reality? No doubt there will be disagreement with Vera's thesis, but if he is right the history of the European forest may need to be rewritten, in order to reflect more fully the series of interactions — between wild animals, livestock, and human beings — that have shaped it. The dark woods of our collective memory may reveal more about our own interior landscapes that about the way things really were.

Tuesday, March 04, 2003

Woodland (I)

Looking out of my window, and over the rusty or — now — snow-covered roofs of the warehouses that are the closest buildings to our office, there is a fine view of wooded hills in the distance; on some winter afternoons the sunsets over the ridge can be spectacular. The rural aspect of the view is, actually, a bit misleading, for hidden beneath and behind those trees are subdivisions, railway tracks, and a busy parkway. It's true, though, that we're fortunate to overlook a landscape that is “still” forested, and has not yet been divvied up for McMansions and shopping centers.

I say “still” in quotation marks because much of the woodland here is, in fact, second growth; photographs from a century ago often show large open fields where today there are dense expanses of trees. This was once dairy country, and until a few generations ago much of the area — all but the swampiest bogs or the steepest rocky hillsides — was parcelled out into farms that supplied milk for the growing population of New York City. At some point the economics shifted; land close to the city became more valuable for housing, and at the same time better transportation made it possible to ship agricultural products from counties farther north or west where land was cheaper. When the local farms shut down some of the farmland was developed, other tracts were preserved as parkland or watershed, and some fields just went fallow waiting for the right buyer and the right use. Walking through the woods, even in the extensive forested acres of the Ward Pound Ridge Reservation to our north, you can still see the farmers' old stone walls, silent evidence, like the ancient Indian mounds of Ohio and the South, of a culture that no longer exists. The reforestation of the area — along with leash laws — has brought corresponding changes in wildlife populations. Deer, once glimpsed only rarely, are now seen as a plague, the wild turkey has returned, and coyotes — not originally native to the region at all — are increasingly common.

The immigrant agriculturalists from Europe who colonized New York and New England in the 17th and 18th centuries were not, of course, the region's first settlers; neither were they the first people to transform the Eastern woodlands. Two decades ago, in a stimulating, brief book entitled Changes in the Land: Indians, Colonists, and the Ecology of New England, William Cronon surveyed the prospect initially encountered by European settlers:
One must not visualize the New England forest at the time of settlement as a dense tangle of huge trees and nearly impenetrable underbrush covering the entire landscape. Along the southern coast, from the Saco River in Maine all the way to the Hudson, the woods were remarkably open, almost parklike at times. When Verrazano visited Narragansett Bay in 1524, he found extensive open areas and forests that could be traversed easily “even by a large army.”
The relatively open condition of the southern New England woodlands was due to the deliberate use of fire by Native Americans. Not the passive Arcadians Europeans often imagined them to be, the Indians in fact were active agents in shaping — one could easily say cultivating — the forest for their own purposes:
The effect of southern New England Indian villages on their environment was not limited to clearing fields or stripping forests for firewood. What most impressed English visitors was the Indians' burning of extensive sections of the surrounding forest once or twice a year. “The Salvages,” wrote Thomas Morton, “are accustomed to set fire of the Country in all places where they come, and to burne it twize a yeare, viz: at the Spring, and the fall of the leafe.” Here was the reason that the southern forests were so open and parklike; not because the trees naturally grew thus, but because the Indians preferred them so. As William Wood observed, the fire “consumes all the Underwood and rubbish which otherwise would overgrow the country, making it unpassable, and spoil their much affected hunting.” The result was a forest of large, widely spaced trees, few shrubs, and much grass and herbage. […]

In particular, regular fires promoted what ecologists call the “edge effect.” By encouraging the growth of extensive regions which resembled the boundary areas between forests and grasslands, Indians created ideal habitats for a host of wildlife species. […] Indian burning promoted the increase of exactly those species whose abundance so impressed English colonists: elk, deer, beaver, hare, porcupine, turkey, quail, ruffed grouse, and so on. When these populations increased, so did the carnivorous eagles, hawks, lynxes, foxes, and wolves. In short, Indians who hunted game animals were not just taking the “unplanted bounties of nature”; in an important sense, they were harvesting a foodstuff which they had consciously been instrumental in creating.
But if the “parklike” woodlands were not aboriginal, neither were the denser forests they replaced. In The Eternal Frontier: An Ecological History of North America and Its Peoples, Tim Flannery describes how, before the arrival of humans, a now-vanished assemblage of “megafauna,” including giant sloths, mammoths and mastodons, and a larger version of the bison, once dominated the continent. Like the elephants, rhinos, and the like of the Old World, these massive grazers and browsers would have imposed strict limits on the growth of vegetation. Furthermore, by creating disturbed “edge” environments by means of their wallows, trails, fallen trees, etc. they created conditions favorable to a host of smaller animals and herbacious plants. The relatively rapid extinction of the large herbivores some 12,000 years ago — possibly (it is still debated) at the hand of human hunters — prompted an increase in forestation and a corresponding decline in ecological diversity, and led, Flannery thinks, to the widespread shifts in the distribution of smaller mammals that have been documented in the following millennia. The burning witnessed, much later, by early European visitors, was therefore a kind of partial compensation for the lost effect of the large grazers.

The present condition of the woodlands of the Northeast U.S., then, can't be explained in terms of a simple opposition between “wild” and “developed” land, but must be understood as the outcome of a specific series of historical changes, in which herbivores, Native Americans, colonists, and suburbanites have all been actors. None of this is to suggest that, since there is no “natural” state to preserve, we should have no reservation about strip-mining (or strip-malling) what open space remains. It does, though, argue for a more complex model of the human-natural interactions that have shaped the landscape. Tomorrow I examine a somewhat parallel argument, this time relating to the deep forests of the European past.