The Passing of the Hemlocks

by Mark Warren

 

       It is likely to be the most devastating environmental loss of our lifetime – like the nightmare visited upon our mountains some three-quarters of a century ago when our native chestnut trees fell to a lowly fungus accidentally introduced from abroad. This time it is a sucking insect from Japan, the Hemlock Woolly Adelgid (Adelges tsugae).

       The eastern hemlock (Tsuga canadensis) – that riverine evergreen that is the favorite tree to so many – is vanishing. If you think that claim an overstatement because the hemlocks around you seem healthy, be apprised now that our time is coming. The trees here in north Georgia lie at the end of a long arc of destruction that began in the mid-Atlantic states where the adelgids were unknowingly delivered to our soil on plants shipped from the Orient half a century ago. Once the adelgids multiplied to sufficient numbers, the infestation traveled quickly north and has now swung south down the Appalachians. The adelgids are here and, sad to say, spreading quickly by way of clinging to the feet of birds. Once in place on a new tree, the aphids suck the life out of every needle and the tree dies – its bare skeleton standing as a monument to remind us how quickly catastrophes brought on by exotic species can sweep through a forest. Or a continental seaboard.

       At the time of this writing, the hemlock woolly adelgid has invaded the watersheds of the Chattooga, Tallulah, Hiawassee, and Toccoa Rivers and Brasstown and Coopers Creek. The cold, stark prediction is this: By the year 2015, we will have lost more than 90% of our hemlocks.

       Besides the aesthetic loss of our defining montane tree, a chain of events will likely follow – one that we cannot yet fully predict but will certainly affect our streams and wildlife. If you have ever fished or canoed a mountain stream then you know that no tree excels the hemlock in creating deep shadow. Unlike white pine, which sheds its lower branches as it matures, the hemlock stretches its thick-laced boughs low over the water, providing cold “holes” and eddies that are instrumental in maintaining the water temperature needed for high oxygen content. (The colder the water, the more oxygen.) With the hemlocks absent from the shorelines, a change of a few degrees could mark the end of certain aquatic species – possibly trout, crayfish and salamanders, for example.

       This same thick foliage that provides unparalleled shade also serves as winter cover for animals seeking refuge from the weather. If you could look at the forest through the eyes of these animals, facing a winter forest without hemlocks would be a sobering proposition. And erosion will tell its own visual tale, as we witness the clean and sparkling quality of our mountain streams yielding to higher loads of silt.

       We don’t yet know how far-reaching the ill effects will creep into the ecosystem. As is usually the case in history, we learn the bigger picture all too late. What we do know is that if we do nothing, our hemlock trees are virtually doomed. So what can we do?

       It is not feasible to save every hemlock. At this early stage in the battle, we have two weapons: beetles and insecticide. Both are expensive. And the adelgids are spreading faster than we can mobilize a comprehensive defense.

       The savior beetles are from Japan and China and dedicate their entire lives to devouring the offending insects, but raising these beetles into hordes of adelgid-eating armies requires the development of full-scale breeding laboratories. The few labs that exist are overwhelmed by the vast areas already in need of the predator beetles. In areas of the Shenandoah Valley, for example, 70% of the hemlocks have been killed. Even where the beetles are being released at infected sites, the work is tedious, situating the beetles on each infested bough of very tall trees.

       The inoculation with insecticide effectively kills the adelgids but it remains a potent deterrent for only two years. And while its lethal effect on the adelgid is encouraging, the potential for poisoning nearby streams is particularly disturbing. Such an inadvertent spread of the chemical could wreak havoc on micro-fauna at the bottom of the aquatic food chain – a mishap that would telegraph its way up to higher organisms. As we know from history, our best intentions with the environment are many times wrought with long-lasting unfavorable consequences. Like DDT, which you and I now carry in our body fat.

       What is the worth of a hemlock tree? A few centuries ago the Cherokee could have satisfied such a nervy question even from the staunchest of skeptics. Both young pale green needles and the inner bark are edible. The inner bark was dried and ground into a flour for cooking and as an antiseptic for wounds and for de-scenting the bodies of hunters before striking out to stalk animals. The outer bark’s astringent qualities served in stanching the flow of blood from wounds and for the tanning of animal hides. A tea made of the needles provided healthy doses of vitamins A and C and was used medicinally for a number of ailments. (There is nothing poisonous in hemlock trees. Poison hemlock comes from an entirely different herb.) A pink dye was extracted from the inner bark. Having the thinnest terminal twigs of all Appalachian trees, hemlock’s dead branches provided ready kindling. Rootlets were dug up and harvested for instant cordage. And perhaps most valued of all, fire (by friction) could be created from the wood. This put the hemlock in that elite category - one of the mythology-trees that in olden days had “swallowed fire.”

       That’s the way we tend to define values – by utilitarian measures. What we often forget is that trees and other green plants literally capture the solar energy that makes life on this planet possible. Every move you make (including your reading these lines) is a manifestation of solar energy “caught” by a green plant and passed on to you by eating either a green plant or an animal that has consumed greenery. Another taken-for-granted by-product of this process is the production of oxygen – using as one of its building blocks, of all things, our waste gas, carbon dioxide. We all learn about this in school, but it is seldom taught with the passion that it deserves. Now think for a moment about which trees are able to perform this miracle during winter. It’s the evergreens. Like hemlock.

       If we can’t save all the hemlocks, it is important that we do save a number of them, so that – should we find a better control to use on the adelgid – we will still have the hemlock gene pool from which to propagate and restore these native trees to their rightful homeland. So what can we do now?

       We must let our government know that this is a priority, so that agencies will represent our heart-felt wishes for a full-scale counterattack to the threat so that funds can be directed toward the battle. Our state and national forests are just that – ours! If this cause stirs our passions, we must be certain that this same passion is represented on our behalf by our officials.

       Share this newspaper article with friends. Talk to people in the grocery store about it.

Then all of us can become a force to be reckoned with by making phone calls to:

1.)Noel Holcomb, Commissioner, Georgia Department of Natural Resources…..404/656-3500

2.)Kathleen Atkinson, Supervisor, U.S. Forest Service…………….770/297-3000

3.)    Governor Sonny Perdue …………………………………..……404/656-1776

4.)    Your senators and congressmen

 

U.S. Senator Johnny Isakson

Washington phone: (202) 224-3643

Georgia phone: (770) 661 0999

Email via web:  http://isakson.senate.gov/contact.cfm

 

U.S. Senator Saxby Chambliss

Washington phone: (202) 224 3521

Georgia phone: (770) 763 9090

Email via web: http://chambliss.senate.gov/Contact/default.cfm?pagemode=1

 

U.S. Congressman Charles Norwood

Washington phone:  (202) 225-4101

Georgia phone:  (706) 886-2776

Email via web: http://www.house.gov/writerep/

 

U.S. Congressman Nathan Deal

Washington phone:  (202) 225-5211

Georgia phone:  (706) 226-5320

Email via web: http://www.house.gov/deal/contact/default.shtml

 

       Explain to each leader or their staff that you want the hemlock crisis to be considered a high priority, not only for the funding of more beetle labs and insecticide treatments, but also for ongoing research for new solutions. Ask them for a special appropriation of funds for a beetle-rearing facility in Georgia. Explain in your own words what hemlocks mean to you and how important they are to the mountain environment and streams. Did you know that 50 inquiries of concern from their constituents will get these officials to regard this issue as one that needs attention?

       If you are an alumna or alumnus of a north Georgia college or university, call the dean and explain the opportunity for the school to embrace this cause. Much of what is needed in this effort is academic mapping and monitoring to understand the status of infestation and remedy – a perfect assignment for biology departments.

       If we don’t do this now, just a few years down the road we will be describing to our grandchildren the majestic evergreen called hemlock that once towered over our creeks and rivers and gave our Appalachian valleys their dark and beckoning mystery. And what will we say when they ask, “What happened to the hemlocks?”