Tuesday, November 9, 2010

Aspens, Dogwood, Ash, Beech and now Hemlocks....as well as a score more of our native trees under increasing attack by exotic insects, pathogens and warming temps--chestnuts gone from our forests and their mast for wildlife.....And over the past 20 years our Hemlock, the majestic river cooling tree(I call it the Trout breeding tree).how many more trees can we afford to lose before disasterous bottom up trophic impacts cause our wildlife populations to crash and burn?

US Forest Service increases efforts to save hemlocks in Asheville area


    ROBBINSVILLE Foresters tried chemicals and even turned loose predator beetles in the battle to save swaths of hemlocks that once blanketed sections of the Blue Ridge Mountains.


    Now they are getting rid of the aftermath with duct tape and explosives.
    The U.S. Forest Service this month will bring down 150 dead hemlock trees in Joyce Kilmer Memorial Forest — some of them hundreds of years old — that pose a hazard to the more than 35,000 visitors hiking in the area every year.
    The invasive hemlock woolly adelgid has nearly decimated the tree species across the southern Appalachians, forever changing the forest and marring mountain views.For Will Blozan, a local arborist known for trying to save hemlocks around the region, the devastation is a result of a lax attitude by the Forest Service since the adelgid starting appearing eight years ago."It's one of the most heinous ecological crimes they could have committed," Blozan said. "Joyce Kilmer is known for its high-quality forest, and they just let it go."
    Dave Casey, a silviculturist heading up the Forest Service's hemlock program in Western North Carolina, said foresters hadn't dealt with such a quick, large-scale die-off of trees since the American chestnut was essentially wiped out by a fungus in the middle of the 20th century.The Forest Service is increasing its efforts this year to try to save what trees are left, using newer techniques and treating hemlocks that haven't yet died."I think we've been pretty open that we didn't do as much as we should have right at first," Casey said. "Obviously, it was related to funding … but part of it might be we haven't seen a chestnut-like extirpation in recent history and some of that might have been lost on us."
    The Forest Service tried treating the hemlocks when the adelgid first hit in the early part of the decade, but treatments in Joyce Kilmer didn't work.Joyce Kilmer is one of the largest remaining tracts of virgin hardwood forest in the southern Appalachians and some trees in the area are more than 400 years old.
     

    Treating hemlocks

    The Forest Service first started treating hemlock trees in WNC in 2005. The agency identified 159 eastern and Carolina hemlock conservation areas, chosen to represent genetic diversity in the forest.Initial treatments focused primarily release of certain predator beetles and treatment of high-priority areas with imidicloprid, a chemical used to kill the adelgid.
    Of the 159 areas, only about 100 proved to be treatable. Some contained no hemlock while the trees were already too far gone in others. The agency treated about 510 acres in 103 conservation areas last fiscal year, a small portion of the roughly 1 million acres that make up the Pisgah and Nantahala national forests.The Forest Service said follow-up monitoring shows that a number of the conservation areas have suffered mortality and can no longer function as genetic conservation areas for the hemlock.
    Rusty Rhea, an entomologist with the Forest Service, said the agency did what it could with the resources it had. He said the goal was not to save all the hemlocks and some areas treated with imidicloprid have survived.
    "The efforts were successful where we could get to the areas," he said.

    Increasing efforts

    The agency spent $239,000 on hemlock conservation in North Carolina last fiscal year. Rhea said the agency is expecting a 35 percent boost in funds for fighting the hemlock woolly adelgid.
    Regardless of any additional funds, the Forest Service plans to hire nine people for two temporary crews dedicated to treating hemlocks.The agency issued a new environmental assessment this summer expanding treatment areas and authorizing the use of new treatments, including a new chemical that works faster than imidicloprid.It also plans to get involved in an experimental technique that will spray fungus on the needles, along with increased use of predatory beetles.
    The number of active sites the agency is treating is expanding on a daily basis, Casey said. The agency is focusing on treating more contiguous blocks of hemlocks.

    "I don't want to say it's a last ditch effort, but that's what it feels like sometimes," he said. "At this point, we are trying to save basically as much as we can, where it makes sense."


    A changing forest

    Blozan, the arborist, said he's glad the Forest Service is increasing its efforts, including the use of new chemicals, but said the efforts may be too late."It's just extremely maddening," Blozan said. "They knew how devastating it was; they knew the trees would die; they had the tools to do it and they didn't do it."The loss of hemlocks in areas like Joyce Kilmer will change the forest, said Jim Vose, a researcher with the Forest Service's Southern Research Station. When hemlocks are lost, there won't be another evergreen species to replace it, he said.Hemlocks provide shade to streams where brook trout thrive and habitat for some endangered species. Hardwood trees that fill in when the hemlocks die don't provide as much shade, take up different amounts of water and could change the composition of the soil.In Joyce Kilmer, rhododendrons will likely fill in the areas where hemlocks are lost, changing both the ecology of the area and how it looks."Not only are hemlocks a keystone species for ecology, but they are also key for the visual look of the southern Appalachians," Vose said. "That loss is definitely going to alter the experience people have in the southern Appalachians."While experts said it could be years or even decades before most dead hemlocks start to fall, many have lost their needles and are starting to loose their branches, changing the cover they provide."There are places in the Smokies that were dark, moist areas with an open understory that are now nothing but saplings," Blozan said. "It's like someone has gone into your house and wrecked it."

    No comments:

    Post a Comment