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Anonymous asked in Environment · 1 decade ago

trees dying out in the forests? any national or regional study or statistics about this?

As I was driving around the Adirondack region, NY this summer, I noticed the alarming number of dead trees on the mountains, on the road side and along the river banks. I know that trees go through cycles of death and birth just like any organism, but I don't remember the number being this great in the past 15-16 years. I also saw similar conditions in the central part of NY(Ulster county)

3 Answers

  • Anonymous
    1 decade ago
    Favorite Answer

    The reason that you notice it on the road sides and waterways is because those are typical routes of infestation. Vehicles transport root fungus and insects and spread them along roadways. Water carries the same objects downstream and spreads the infestation along the banks.

    Emerald Ash Borer

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients. Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. Emerald ash borer is also established in Windsor, Ontario, was found in Ohio in 2003, northern Indiana in 2004, and northern Illinois in 2006. Since its discovery, EAB has:

    • Killed more than 20 million ash trees in Michigan, Ohio and Indiana. Most of the devastation is in southeastern Michigan.

    • Caused regulatory agencies to enforce quarantines ( Ohio, Indiana, Michigan) and fines to prevent potentially infested ash trees, logs or firewood from moving out of areas where EAB occurs.

    • Cost municipalities, property owners, nursery operators and forest products industries tens of millions of dollars.

    Forest Pests that Continue to Significantly Impact Adirondack Forest

    Forest Pest Trees Species Affected Damage and Effects Tree Signs & Symptoms Method of spread Year detected in US Likely Original Source of Pest Result

    Armillaria (fungus)

    Armillaria spp. Hundreds of species Root fungus lives as a parasite on living hosts. Affects phloem and xylem transport and causes general health decline in infected trees.

    White mycelial mats beneath bark. Loss of foliage (flagging) on upper branches.

    Natural component of temperate and tropical forests.

    [ Also exists as a saprophyte on dead woody material ]

    May be symptomatic of ‘maple decline.’

    Infected trees may succumb quickly or live on in a weaken state.

    Common Pine Shoot Beetle

    Tomicus piniperda Scots, white, red, and jack pines with spruce, fir and larch as alternative hosts Adult beetles enter one-year-old or current year shoots in the upper branches to feed, hollowing out 1-4 inches of the shoot, killing the shoot.

    Infected branch shoots bend at the point of entry, yellow and eventually break off.

    Adult beetles are weak flyers, but are transported by wind

    OH - 1992 Native to Europe and Asia

    Exists from Great Lake States to NY – all under active quarantine to limit spread. If infected, the destroyed tip shoots may damage tree form and future growing stocks.

    Gypsy Moth

    Lymantria dispar Oaks are the preferred hosts, but also: apple, basswood, birch, poplar and willow

    Caterpillar feeds on foliage and weakens trees by defoliation. Several years of repeated defoliation stresses trees and can lead to death. After 2-3 years of defoliation some trees are weakened to a point where they cannot recover. As food sources dwindle, GM populations crash (with the help of introduced parasites) and recovery of the healthier trees occurs. Tree growth is significantly reduced during periods of defoliation. Long distance spread occurs when egg masses are transported by vehicles.

    Short distance spread results when small caterpillars are blown by the wind. MA -1869

    Accidentally reintroduced several times with slightly different strains

    Europe and Asia

    Introduced to develop a strain of silk moth that was resistant to disease to begin a commercial silk industry.

    Over 20 parasites introduced to control GM. After a significant outbreak, forest composition is altered to less-susceptible tree species (i.e. fewer oaks). Has the potential to be a significant pest in areas where there are large concentrations of oaks. Largely controlled by an introduced insect pathogen, Entomophaga mamaiga

    Forest Tent Caterpillar

    Malacosoma disstria Hubner Aspen and sugar maples preferred – many other species also. Caterpillar feeds on foliage and weakens trees by defoliation. Several years of repeated defoliation stresses trees and can lead to death. Outbreaks typically last 3 years, then subside due to diminished food sources and a surge of native predators, parasites and disease. Although defoliation kills few trees, tree growth is significantly reduced during periods of defoliation. Adult moths are transported by wind. Native insect Reported in colonial times Outbreaks are cyclic, occurring every 10-20 years. A significant outbreak is occurring in St. Lawrence County and is ‘blowing’ east into the Park.

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  • Anonymous
    1 decade ago

    Black Forest in Germany, acid rain.

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  • 1 decade ago

    Pollution and acid rain

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