Jul. 20, 2011

Science Rocks: The Blight of the Hemlock

by NIMBioS

Video by NIMBioS

In this video, Jay Clark performs his song, “The Last Hemlock,” which he composed during his time as a Songwriter-in-Residence at the National Institute for Mathematical and Biological Synthesis. Written by Clark, who has a Ph.D. in wildlife ecology, the song tells the story of the blight of the Eastern Hemlocks in Southern Appalachia. The Eastern hemlock and the Carolina hemlock along the East Coast has been devastated by the hemlock wooly adelgid, an aphid-like insect that originated in Asia and that infests hemlock species. It was accidentally introduced into the forests of eastern North America in the 1920s. The adelgid attaches to the stems at the base of the needles and both kills the needles and prevents new growth. The tree often dies within four years, although some trees survive longer while exhibiting diminished growth. There are several treatment options ranging from chemical treatments to predatory insects to insecticides. But if untreated, death is almost inevitable. In the southern Appalachian Mountains, 80 percent of the hemlocks have died due to infestation. Hemlocks play an important role by providing deep shade along creeks and by helping maintain cool micro-climates critical to survival of trout and other cold water species. Clark’s song ends with a short refrain, a note of optimism, from Aaron Copland's "Appalachian Spring." The lyrics are:

A night bird sings…a lonesome lullaby
Embers glow beneath a purple sky
Heavy eyes…lead to Appalachian dreams
Of being comfortably lost
Beneath the hemlock trees

A black-throated green…warbled in my ear
Said he was mourning the passing
Of his home so dear
He could barely sing…through tears in his eyes
Cause today the last hemlock died
Today…the last hemlock died

And gray skeletons stood tall
But in time they will fall
To a forest floor that knows shade no more
Evergreen had turned to gray
And he had dreaded the day
That the last hemlock died
Today..the last hemlock died

I asked him…what caused this tragedy?
He said it’s a product of your negligence, apathy, & greed
You brought it over…from a foreign land
And the blood of the hemlocks is on your hands

Then I awoke…from my dream
Wiped the sleep from my eyes and gazed up through the evergreens
Then I heard…a familiar song
It was a black-throated green…welcoming the dawn

And the hemlocks stood tall
But in time they will fall
To a forest floor that knows shade no more
And evergreens will turn to gray
And I dread the day
That the last hemlock dies
Lord, please forgive us…
When the last hemlock dies

For more information about the songwriter-in-residence program, visit http://www.nimbios.org/songwriter. For more information about how to help save the hemlocks, visit http://www.savinghemlocks.org/.


In Biology by Numbers, learn about the ways math can solve biological problems. Produced by the National Institute for Mathematical and Biological Synthesis (NIMBioS).

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