As Scandinavia Warms, Spruce Bark Beetle Flourishing In Swedish Forests - IHT

[hatrack]

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The beetle has caused havoc in Central Europe's mountainous spruce forests for centuries, drilling through the spruces' bark, where the insects lay their eggs, eventually killing the tree. It takes about 6,000 beetles to kill a 25-meter, or 80-foot, spruce. Until now, the beetle has never been a big problem in Northern Europe, mainly because long and cold winters kept their numbers down. But for this year and the next, experts are predicting an explosion in the number of beetles, causing the death of up to 60 million cubic meters, or 2.1 billion cubic feet, of trees - almost two-thirds of the yearly regeneration of Sweden's forests.

"This is the worst situation we've ever seen here in Sweden," said Bo Langstrom, a professor of entomology at the Swedish University of Agricultural Sciences. "Usually, the beetle only produces one brood per year here in Sweden. But last year, for the first time, it produced two." "If this continues, we will have much more serious damage than ever before," he said.

Climate change is a likely culprit, as manifested in the frequency and intensity of storms. The problems began when one of the biggest storms in modern times hit southern Sweden in January 2005, felling 75 million cubic meters of trees, mainly planted spruce. Many experts believe that the way that trees have been planted and harvested - on formerly open fields, and next to big clear-cuttings - have made them vulnerable to strong winds.

The felled trees provided the perfect breeding ground for the bark beetles, and when the storm was followed by the longest and warmest summer on record in 2006, the beetles were given the chance to greatly increase their numbers. Then another big storm hit southern Sweden this January, and spring arrived early, letting the beetle start breeding quickly. "Now we just have to pray for a cold and short summer," said Mattias Sparf, a forest consultant with the Swedish Forest Agency.

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http://www.iht.com/articles/2007/05/02/news/beetle.php

[Cleita]

1. We've had this same problem in our Sierras

and many botanists credit the infestations with lack of genetic diversity from the trees. It seems that many of the forests are third growth after bad logging and replanting policies in the previous two centuries. In an old growth forest only some of the trees are susceptible, but with clear cut logging practices, the trees are replaced with saplings from the same genetic source and often of just one species like Ponderosa Pine that they want to log again when the trees mature. The Swedes might want to take a closer look at their logging practices.

[lyonn]

2. This issue is as critical as oil, almost. We have abused the

tree population. Have seen the redwoods in CA when they were thick and now? So sad. The lumber companies have had way too much control over what is cut and how, meaning clear cutting. In the past they were required to leave trees and no clear cutting was allowed. Since moving away from Calif. and not seeing the change each year it was a shock to see how it is done now.

[The2ndWheel]

3. That's a shame

We attempt to destroy diversity and control nature for only our benefit, and then run around and question what we'll do to fix it. Probably destroy diversity and control more life for only our benefit. To go the other way would mean we lost the fight against evolution, diversity, and our habitat.

[Wilderness Sportsman]

4. Same thing for the rockies.

A likely link to climate change.