There has been a lot of speculation about pandemics lately: how serious are they? What causes them? How can we stop them? Are all these inconveniences really necessary?
With COVID19 limiting our activities, we search for clues from the 1918 Flu pandemic to try and make some sense of often conflicting advice and predictions.
Here in the Southern Appalachians, we can look at the effects of pandemics that were a lot closer to home and a lot more recent than 1918. In the natural world pandemics arise from time to time and for the most part have been allowed to run their course. We can learn from these, if we will.
Prior to the 1930s, the chestnut tree was one of the dominant species in these mountains. In some places, one out of every three trees was a chestnut. Economically, locals depended on the chestnut for the wood, the tannin and the nuts.
But starting in the early 1900s, the Chestnut Blight was somehow introduced into the northern United States (probably from Asia, via Europe … sounding familiar?) with the result that eventually billions of chestnut trees were wiped out. The Chestnut Blight is spread from one tree to the next by either wind or insects.
If forest managers had taken the extreme step of cutting or burning some of their chestnut stands, or let’s call it distancing the healthy trees from the infected ones, perhaps some chestnuts could have been saved. Unfortunately, nobody really believed that the Blight would become so strong.
Nobody could imagine the Appalachian Mountains without chestnuts. So, they waited too long before they tried to stop it.
Just a few years ago, the Southern Pine Beetle arrived, uninvited. It had been a problem farther south, but with the slight warming of average temperatures, the beetles were able to chew their way north into our area.
The Southern Pine Beetle is pretty specific about what it prefers to eat: yellow pines. They eat the inner part of the bark, effectively ringing the trees. There are several management actions that can be taken but they all come down to this: you have to distance the healthy pines from the infested trees or the beetles will continue their devastating march.
The beetle problem is complicated by the fact that beetles can move on their own, unlike a virus or blight, so the buffer between sick and healthy needed to be big … too big for many people. A lot of tree owners waited too long and then watched helplessly as their years of investment into the growth of yellow pines was devoured by tiny insects.
In caves around Appalachia, bat populations are being ravaged by the White Nose Syndrome. Since they live in close proximity to each other, in fact snuggling up during cold weather hibernation, bats are especially susceptible to infectious diseases. The White Nose Syndrome attacks during the cold season when the bats’ metabolism has slowed way down to hibernate.
WNS makes them use energy faster than they should, even causing them to wake up more often during warmer spells. The result is they use up too much of the fat they built up for hibernating and they essentially starve to death. The fungus can be spread between bats by contact with an infected individual or by touching a place on the wall of the cave that has somehow gotten the fungus on it.
Humans seem to be the biggest spreader between caves. We will visit one cave, maybe not even realize there are bats present, pick up some of the fungus on our shoes and equipment, and then visit another cave without washing our shoes and equipment off.
The White Nose Syndrome has spread and continues to spread across the eastern U.S., killing up to 90% of some bat species. If the healthy bats could be separated from the infected ones, they might stand a chance. But bats are social creatures and social distancing in bats is probably impossible.
If you drive between Sugarlands Visitor Center and Clingman’s Dome in the Smokies, there is one horrific view of the dead Frasier Firs. They are the victims of the balsam woolly adelgid, a killer insect that has been in the USA for more than 60 years.
The adelgids can be spread by wildlife or wind and, like COVID-19, they kill mostly the old mature individuals.
In each of these pandemic examples from nature, scientists had to carry out research to see what they were dealing with and how best to treat the infected individuals. In each case, if they had been able to isolate the infected trees or bats from the rest of the population, they could have saved millions of individuals while they looked for a cure.
Instead they were forced to accept the concept of herd immunity. In all of these examples, the population suffered incredible losses, as did the ecosystems that depended on them. With trees, isolation is difficult because they cannot move; you must kill the sick one to save the others.
Dealing with COVID-19, we humans have it pretty easy. We don’t have to wait for herd immunity to kill off millions of our species. We can take a giant step away from others and put on a mask, while the experts look for a cure or a vaccine.
We can learn from nature, if we will.
Kathryn Hunter is from McMinn County and holds a bachelor’s degree in Forest Resource Management from the University of Idaho and a Master of Forestry from Yale University. She has worked with the USDA Forest Service locally as well as living and working in natural resource management and protected area conservation in eight foreign countries.