REGIONAL— Earlier this week, PBS aired a two-part Ken Burns series, “The American Buffalo,” that recounted the senseless and tragic destruction of an iconic North American species that once dominated vast swaths of the continent. It wasn’t the first time that rapacious Europeans wiped away the natural abundance and beauty that had been the honored and protected birthright of native North Americans for millennia.
In his new book, “White Pine, the Natural and Human History of a Foundational American Tree,” UMD professor emeritus John Pastor provides a fascinating and equally tragic story of the loss of the once-vast forests of white pine that spread from Maine to the prairie edge in northern Minnesota. As with the buffalo, it was the same genetic lust for monetary wealth and a worldview that saw the natural world as nothing more than a target for plunder, that drove the destruction of the original white pine forests and left virtually nothing but the occasional “Lost 40” remaining of an ecosystem that once stretched for thousands of miles.
While Pastor tells that story, he doesn’t dwell on it since there is so much more to know about this remarkable tree. Pastor, an ecologist who focused his research and teaching on the natural history and ecology of northern ecosystems, offers any number of insights into the white pine and its role in world history. The white pine’s strength, massive size when mature, and supple wood made this tree the most highly-desired of all for the creation of the ship’s masts that powered the British Navy of the 1600s and 1700s. It was the trade in masts, which the British needed by the thousands, that became one of the early American industries and began the centuries of exploitation of the white pine that finally came to an end with the cutting of the last of the original white forests in northern Minnesota by the 1920s.
The destruction of the white pine had devastating consequences for the wild creatures that made their homes in these once-complex ecosystems. It also attracted the growing concern of those Americans who recognized what was being lost in the mad rush to exploit this vast natural resource. People like George Perkins Marsh, the author of “Man and Nature,” an 1864 classic that was as influential as Darwin’s “On the Origin of the Species” in its day, and Henry David Thoreau of “Walden” fame, first planted the seeds of a young conservationist movement that was ultimately taken up by many others. Their combined efforts came too late to save any but a smattering of the remaining herds of buffalo or a few scattered remnants of the original white pine forests, but they set the stage for an environmental movement that ultimately reshaped America’s relationship with the natural world for the better.
Pastor includes other interesting insights that warrant a mention. While the white pine dominated the forests of northeastern North America as far west as Minnesota, the continent is home to a remarkably diverse array of pine species, certainly as compared to Europe and northern Asia, where forests are largely limited to a single pine species, the Scots pine.
Pastor highlights a now well-documented theory that posits that the 40-odd species of pine in North America originated as a result of the fluctuating climate during the Eocene, which began nearly 60 million years ago. The theory, developed by Constance Millar, a conifer biologist with the U.S. Forest Service, proposed during warm, tropical periods during the Eocene, North American pines retreated to isolated refugia in the high altitudes of the young and then-growing Rocky Mountains. “The complex terrain of different mountain ranges and valleys isolated the populations from one another and prevented cross-pollination,” writes Pastor. As the isolated populations adapted to their new environments, they grew apart from the genetics of their forbearers and eventually became separate species.
As a cooler climate returned, the pines spread to lower elevations, with implications explained by Pastor. “Many previously isolated populations could no longer interbreed successfully and had therefore become separate species, while other interbred and formed new hybrids. Some of the hybrids were less able to compete with their parent species and went extinct, but others outcompeted their parent species and drove their parents to extinction or into marginal habitats.” With the return of more tropical conditions, the new assemblage of pines retreated to the high altitudes, only to continue their genetic alterations over time. As this pattern repeated, the genetic pools of North American pines became remarkably well shuffled, resulting in the many species we see today.
While the past shaped all North American pines, including the white pine, the future may have the greatest impact of all, Pastor notes. With climate change warming the planet at a pace that far exceeds the climate fluctuations of the past, Pastor notes that the conditions required for white pine survival are likely to shift northward, bringing uncertainty as the tree is forced to compete with other species in new landscape. Once again, it is the activities of humans that threaten the white pine’s future. Yet, as Pastor writes, research is already underway to find ways to ensure this remarkable tree’s survival. That’s a story yet to unfold.
Pastor’s book is published by Island Press and is widely available at area bookstores or online.