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. […]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.
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.