This past week was both a fun time of memory building with my family, and a terrible tease all at once. While my wife and I had a wonderful week with our two little girls at DollyWood in Pigeon Forge, TN the tease came in driving directly through the heart of one of my favorite backpacking destinations: Great Smoky Mountains National Park.
The Smokies turn 75 years old this year (the park, not the billion-plus-year old mountains) and it remains the most visited national park in the nation. However, as we stopped at the crest of the range at Newfound Gap (both to assuage the cries of, “I’ve gotta PEE!” and to indulge my desire to reminisce on the AT) I noticed something troubling that has been more apparent each time I return to the Smokies: dead trees. Turns out there are 3 causes for the die-offs that are all interrelated: BWA, HWA, and Acid Rain. BWA stands for Balsam Woolly Adelgid, an insect that arrived on trees from Europe and spread into the Smokies in the early 60s. The primary target of the BWA is the Fraser Fir which is indigenous only to the Southern Appalachians, farmed for use as highly sought-after Christmas Trees, and was once the dominant tree in the uppermost subalpine zone of the 5000+ elevations in the park. By injecting adult trees with a toxin, BWA renders the Fraser unable to absorb nutrients and it effectively causes death by starvation. To date 95% of the Fraser Firs in the park have been killed.
HWA stands for Hemlock Woolly Adelgid which is another bug and a newer threat. This bug is of Asian descent and wasn’t discovered in the park until 7 years ago. As the name suggests, this pest targets Hemlock trees which grow at elevations below the Spruce-Fir forests at the crest of the range. Hemlocks account for some of the largest living trees in the park, with some in old-growth groves that are over 400 years old. Unfortunately every hemlock in the Smokies has already been affected by HWA. A difference between BWA and HWA is that HWA affects trees of all ages whereas BWA only affects mature trees. While this is good news for Frasers (the 5% that are left anyway) it is really bad news for Hemlocks and the ecosystems that depend on them (pretty much everything below 4500’).
The third cause is Acid Rain, or perhaps more appropriately: Acid Clouds. The number one offender here is coal burning power plants to the east of the Smokies which pour tons of harmful pollutants into the air every day, not the least of which is sulfur. The highly acidic emissions from these plants results in clouds that condense and hover over the forests of the Great Smoky Mountains with measured Ph levels as low as 2. Coal Power is the single greatest source of greenhouse gas emissions in America, and a major contributor to smog and acid rain.
So what are the solutions?
For BWA several ineffective treatments were attempted prior to discovering an effective one in the 1980s. A fatty spray applied to the trunks of trees has proven effective in prevention, but by the time it was discovered, the vast majority of the park’s firs had been infected. The other limitation to this treatment’s effectiveness is that trees must be treated individually and the altitude at which these trees grow often present access issues.
For HWA, the initial approach was a treatment with chlorinated nicotine, but like the BWA treatment had limitations in terms of practical implications of treating trees individually. As a result, the park service began to explore alternative means of treatment and have recently begun using a small beetle which is a natural predator of HWA. While it will never be a complete treatment, it is hoped that this sustainable, biological treatment will be effective in controlling the spread of HWA.
The solution for reduction of acid rain is obvious: fight coal power, reduce reliance on fossil fuels, support green power initiatives. And here is where the interrelatedness comes in: fighting the source of the acid rain will also help to stop the spread of these Woolly Adelgids. How? The recent spread of Woolly Adelgids and increase in their devastation is a direct result of global climate change brought on by the buildup of greenhouse gasses. Research has shown that as climate change results in warmer average winter temperatures, the lifespan, reproduction rate and habitat range for Woolly Adelgids are all growing. Because of the buildup of greenhouse gasses, these insects are able to survive winters, reproduce more times per year and survive in higher latitudes and altitudes than ever before.
To get involved and work to fight climate change at home and in your community follow the following links:
Natural Resources Defense Council: http://www.nrdc.org/air/default.asp
Sierra Club: http://www.sierraclub.org/
National Parks Conservation Association: http://www.npca.org/
We Can Solve It: http://www.wecansolveit.org/