The Witness Trees

Reaching into the past, Melissa Thomas-Van Gundy paints a vivid picture of a highlands forest dense with white oak, flaming sugar maple and American beeches, with a scattering of yellow poplar, wild cherry and spruce pine and, here and there, a singular crab apple, elm or soaring sycamore tree. That’s how the Monongahela National Forest in central West Virginia may have appeared before it was slowly distributed among settlers from 1752 to 1899, Ms. Thomas-Van Gundy suggests in research recently published by the Forest Service. As the land was divvied up, surveyors documented the trees that rested at the imaginary corners and angles of the parcels to mark their boundaries. They were called “witness trees” – an expression also used today for trees that were present at key events in American history like Civil War battles. But in this instance, a witness tree was something humbler and more pragmatic — “that which witnesses a corner,” as Ms. Thomas-Van Gundy put it. In the 1930’s, the park staff of Monongahela National Forest translated all of these notes and sketches into maps illustrating the spread of various species. Later, this intricate cartography was revised and digitized in a project completed in 2005.Using those digital maps, Ms. Thomas-Van Gundy and her co-author, Michael P. Strager, applied a technique called indicator kriging, which takes each tree species and, according to its dominance in the records, “spreads it out” across the landscape “based on probability,” as Ms. Thomas-Van Gundy put it. They also analyzed features like elevation and topography to describe likely species composition in specific areas. Finally, they produced maps showing what the landscape might have looked like before logging and farming got under way...more