I, alongside my classmate and research partner, Gus, have been assigned a semester-long individual research project that entails the coring and studying of Eastern and Carolina Hemlock trees. Hemlocks trees across the world have been overwhelmingly affected by the Hemlock Woolly Adelgid, an insect originating in East Asia, of the order Hemiptera. The Woolly Adelgid was first recorded in America in 1951, and throughout my lifetime, almost all Hemlocks in America have been affected by the Adelgid, decimating the Hemlock population. Eastern Hemlocks, Tsuga Canadensis, used to be one of the most prevalent tree species in Eastern U.S. forests. Carolina Hemlocks, Tsuga Caroliniana, are endemic to the Southern Appalachians, and generally smaller than their Eastern counterparts. Today, one can still see Hemlocks throughout the forests in Southern Appalachia: if you scan the canopy you can spot conspicuously dead, grey trunks with thick, bare branches sticking into the air.
Woolly Adelgids spotted on a Carolina Hemlock at Devil's Courthouse.
My research partner and I are still in the sample-gathering stage of our project. We have allocated our time to coring trees here at the Highlands Biological Station, and at Devil's Courthouse on Whiteside Mountain. All of the Carolina Hemlocks in our study have been found at Devil's Courthouse: they are becoming increasingly rare. We use an increment bore to extract a thin tube-shaped core from the tree, and then store the core in a straw (we recently procured some nice, large straws from a particularly philanthropic McDonald's) until we can transport it back to campus. Once back, we must wait for the cores to dry, then we mount them onto wooden stands using wood glue. We then sand the cores using a hand- and belt-sander, until the top surface is flat and the rings of the tree are readily apparent.
A sneak peek into the tree coring process!
We decided to wait and develop a hypothesis for our project once we have been given an opportunity to analyze the prepped and scanned cores. We are faced with the responsibility of identifying an aspect of a dying species to focus our research on. This raises many philosophical questions, at least for me. We understand the outlook for Eastern and Carolina Hemlocks: if they go untreated, they will eventually die. The Forest Service does not have access to all of the Eastern and Carolina Hemlocks; some of the Hemlocks they do have access to will remain untreated due to budget and staffing limitations. How long will they keep treating the Hemlocks? Forever? Is it worth it to expend limited resources on a species of tree that will ultimately disappear? Is it cruel to give up? Do we mourn the loss of the unique ecological niche that Hemlocks created, or do we wait expectantly for another to take its place?
In many ways, the Hemlocks represent our larger changing natural world. As a budding environmentalist, I am often confronted with questions of the future. With so many variables out of my hands (almost all of them, in fact) how do I justify to myself going into the field of ecology? Our natural world will change no matter what we do: as scientists, we must decide our role within that shifting atmosphere, and decide where to place our hopes, and where to draw the line. Sometimes studying Hemlocks feels like standing on a sinking ship; but, at the end of the day, we mustn't give up on these species just because their outlook is poor. We can learn from mistakes made in the past, and hopefully contribute to a larger understanding of dendrology and ecosystem interactions.
I am not yet sure where this research project will take us. I can only hope that Eastern and Carolina Hemlocks are around for many years to come, and that the sustained efforts of forestry management professionals and researchers such as us contribute to that longevity.
Written by Scout Allen