A summertime walk along a cool, shady mountain stream in the Chattahoochee National Forest in North Georgia is always a pleasure for me. But these days, the streams, and the forest in general, aren't as cool and shady as they once were.
The Eastern hemlock, one of the grandest, shadiest and most common trees of the southern Appalachians, is dying off. A voracious and exotic insect pest from Asia, the hemlock wooly adelgid, is killing hemlocks by the tens of thousands. The tiny adelgid sucks the sap from hemlock needles, depriving the tree of water and nutrients.
Foresters predict that within a decade, if the pest is not controlled, Georgia and neighboring states will lose more than 90 percent of their hemlocks. Georgia faces losing the hemlock as a forest species, an ecological catastrophe that would be comparable to the loss of the American chestnut tree during the last century.
The destruction already is severe and widespread. That was starkly evident last weekend when I went with Atlanta Audubon Society volunteers to check on three stands of hemlocks in the Cooper Creek Scenic Area and Mulky Gap area in Fannin County. We saw dozens of dead or dying hemlocks of all sizes. Many of the green trees, though appearing outwardly healthy, had early signs of infestation -- white, wooly egg sacs, like cotton swab tips, clinging to the undersides of the needles.
“It’s so sad to see,” Joy Carter of Atlanta said.
Carter and fellow volunteer Amy Leventhal of Avondale Estates regularly monitor the stands as part of an Audubon project in conjunction with Clemson University. Clemson is one of several institutions with special labs to raise predatory beetles, native to Japan, that exclusively attack the adelgid. Other labs can be found at the University of Georgia and North Georgia College & State University in Dahlonega.
The beetles are released in hemlock stands in hopes of controlling the adelgid. Carter, Leventhal and other volunteers monitor the stands to help determine if the beetles are reducing the infestation rate.
No one is sure if the beetle-release efforts will save the hemlock. But if we lose the once durable and shade-tolerant tree, we likely will see declines in other species that favor it for food and shelter. One of them is the black-throated green warbler, which we heard singing in the hemlock stands last weekend.
More information: www.atlantaudubon.org; The Lumpkin Coalition (www.lumpkincoalition.org) and Georgia ForestWatch (www.gafw.org).
In the sky: The moon is in last quarter phase. Look for it to rise about midnight and set around midday, said David Dundee, astronomer with Tellus Northwest Georgia Science Museum. Mercury is very low in the east just before sunrise. Venus is low in the west just after sunset and sets about two hours later. Mars sets in the west after midnight. Jupiter rises out of the east about four hours before dawn and appears near the moon on Sunday evening. About the same time, the very faint planet Uranus will be visible with binoculars near Jupiter. Saturn is high in the east at sunset.
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