Something Positive could the Swiss Federal research Institute WSL, according to their survey in all forest Switzerland coalfields to be reported: Although the country-wide amount of bark beetle infested spruce wood in 2018, has doubled over the previous year, but the record of 2003 was not reached by far.
This is a small consolation does not apply to the Canton of Zurich: Urs Kamm of the Department of forest of the Zurich building Department reports on request: “The number of infestation foci in the Zurich forest is practically the same as in 2003.” Particularly strong are the woods in Winterthur and the surrounding area, in the uplands and in the wine country are affected.
source: office for landscape and nature.
in 2018, reported the Zurich area Forester 1547 beetle ester. This refers to a group of trees with at least ten infested trees with a trunk diameter of at least 16 cm at chest height. In 2001, as the impact of hurricane Lothar 1319 of Infestation have been detected, in the heat year 2003, 1632. Across the country, there were herd in the past year 9100 Infestation.
In the forestry circles 4 (Winterthur and the surrounding area), and 5 (wine country) were not recorded absolute record values in 2003 there were 270 or 196 beetles ester, in the last year, 374 and 348.
Burglind and summer Heat
the Canton of Zurich is particularly affected by the damage, according to the comb in order that the heat wave and drought in this Region was more pronounced than in the Alps or in the Western part of Switzerland.
in fact, the Zurich-based forest has been buffeted in the January of the first winter storm Burglind, which led locally to a bunch of storm wood. Just in the wine country there was in the previous year, locally violent storms, and thus suitable brood material for the beetle. In the spring, the temperatures rose significantly, and in the summer it was exceptionally hot and dry.
larva: There was a result, in many regions three instead of only two generations image: Raphael Moser
“This is a combination of numerous spruce trees made vulnerable to the bark beetle and offered this food in Abundance,” says Beat Forster of the WSL. The book printer, a beetle from the subfamily of bark beetles, was able to create in the deeper layers instead of the usual two to three generations. “The currently overwintering beetle population is larger than in previous years.”
in time put away
last summer, the forest had to carry out the owner of the so-called forced benefits, so trees except for Plan cases. In the Canton of Zurich between April and September, more than 80’000 cubic meters, only about twenty per cent less than in the record year of 2003. Further, such emergency Fällaktionen are currently being made.
see this in the tribes was, among other things, in the Winterthur region, but also in the wine country by large quantities of felled Spruce, which are stored outside of the forest. Because storm – and beetle-infested wood has been cleared away from the Zurich forests quickly and efficiently.
beetle-infested wood on the Seemer Buck between Winterthur city and Sennhof. Photo: Madleine Schoder
bark beetles do not benefit, as is often assumed, of the remaining deadwood. They thrive only on freshly dead pines that are still in the juice. Newly infested spruce trees need to be cleared before the next beetle generation to fly out.
Financial loss
For the forest owners mean such uses, in part, to massive financial losses. On the one hand, the beetle wood is often inferior, on the other hand, will decrease due to the greater supply at a constant demand, prices.
The experts comment. According to Beat Forster from the WSL, the pest situation is likely to remain this year, too, a critical, even without severe storms or prolonged periods of drought. Because in the woods, numerous weakened spruce trees, which could be a godsend for bark beetles.
(Tages-Anzeiger)
Created: 19.02.2019, 10:53 PM
