The air is thick with power smoke and the heat of mid-afternoon. McLaws' confederate division surges across into the Wheat Field, into the Peach Orchard, and drives the Union III Corps back into...dense thickets of Japanese barberry, where the charge collapses in a tangle of thorns. Until a few years ago, if you stood at this historic part of the Gettysburg battlefield, you would have been hard pressed to imagine the landscape as it was on that day, because invasive species had dramatically altered its former farm fields and fence rows beyond recognition.
Invasive plants have many acknowledged environmental and economic impacts, but in historic places like Gettysburg they can also threaten our cultural heritage.
Consider this image, a painting by acclaimed Civil War historian and artist Don Troiani who is one of the great masters of military art and nearly fanatic about historic accuracy. He does not dress his models in reproduction uniforms but in items from his vast collection of original clothing, weapons and accouterments. He demands that his models have 19th century physiques and facial features (no reenactors with waists over 32 inches need apply). He pores over historic photographs and visits the sites of the events he depicts to ensure that the perspectives and terrain are as close to what was there at the time as possible.
Yet for all this extraordinary attention to detail, Troiani has painted an anachronism in this marvelous scene entitled "Retreat by Recoil", which shows Bigelow's 9th Massachusetts Battery on the verge of being overrun by a brigade of howling Georgians. There in the lower right corner, in among the field stone, is a spiky shrubby form that can only be Barberry. Now Berberis vulgaris or common barberry was certainly introduced to North America prior to the Civil War, but because it harbored a wheat rust it was aggressively rooted out and fines were imposed in some states for those who allowed it to remain on their properties. This scene is at the Trostle farm, not far from Gettysburg's bloody Wheat Field, and so it is safe to assume that Troiani painted what he saw at the site - Berberis thungbergii, or Japanese barberry.
The problem is, Japanese barberry was first introduced at the Arnold Arboretum in Boston in the mid- 1870s from seeds collected in St. Petersburg, Russia. Gettysburg, you will recall, was fought on three days in July in 1863. Troiani has painted an extremely realistic and accurate study of the men and uniforms of the period, but unwittingly, an invasive species has been introduced to the historic flora of the site before its time.
Only a Civil War buff and invasive species expert could have made this connection, perhaps, but that is what is so insidious about the cultural impacts of invasive species. Without our being aware, they so insinuate themselves into our landscapes and waterways that we become accustomed to their presence, even forget that they are naturalized and not part of our native ecology. The green crabs I hunted for under rocks at my grandparents' home in Buzzard's Bay are invasive, as are the meadows of Loosestrife in the Millbrook Marsh where I spent many a delightful childhood hour mucking about in swamps. Gettysburg with barberry is not the historic landscape it seeks to preserve and robs us of our shared heritage.
It is very hard to remove vegetation and kill animals within National parks. The mandate for historic preservation also encompasses protecting the entire flora and fauna of these places as well, and until the threat of invasive species was widely recognized it was difficult for land managers to get authority to control these plants on National park lands. The current leadership at Gettysburg Military Park is committed to both ecological and historic reclamation and has done a tremendous job removing barberry and other invasive plants, as well as restoring the slopes of Little Round Top to their open condition at the time of the battlefield. Now as one stands where the 140th and 146th NY (my gr-gr-step grandfather among them) pushed back the confederates from the summit, it is an open slope rather than the deep forest to which it had succeeded that lies in view.
I believe these steps are tremendously important at a site that is meant to convey a static moment in time, and commend the park Service and leadership for following this policy. Now, as Wofford and Barksdale and Kershaw and the rest press on against the wavering blue lines of memory, they are met as of old with bayonets of steel rather than the thorns of barberry.
update (7/7/226): You can see a close up of the offending plant in a follow up post here.