In the last three years Germany, and especially North Rhine-Westphalia, has experienced severe and persistent dry periods.
The State Office for Nature, Environment and Consumer Protection (LANUV) last year
the lowest groundwater value ever measured was found at 720 of 2,000 measuring points in the country.
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Due to the drought, but also due to the effects of pollutants, the forest suffers,
currently especially the spruce stands in the country.
In Germany the spruce covers 30% of the total forest area,
and is therefore the most common tree.
Spruce wood is an important raw material
it is used as construction timber, furniture wood or for paper production.
Forestry in North Rhine-Westphalia provides around 150,000 jobs.
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There are around 150 species of bark beetles in Europe,
they attack weakened or sick trees,
and ensure that there is enough deadwood in the forest.
They are useful insects.
The most common types are the engraver (Pityogenes chalcographus) and letterpress (Ips typographus).
They are dark brown in color and slightly smaller than a grain of rice.
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When a bark beetle visits a tree, it drills a hole in the bark,
and builds a brood chamber in the living skin between the bark and wood - the cambium.
However, he can only do this with weakened or diseased trees,
who don't have enough resin to defend themselves.
Healthy spruce trees bond the chamber and the beetle with their resin, and that solves the problem.
But if the beetle is successful, it forms an attractant to attract other conspecifics.
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A healthy tree can repel up to 200 bark beetles.
A female beetle can lay 30,000 eggs a year.
Too many bugs or too little resin interrupt the flow of sap in the tree trunk,
destroy the nutrient pipes and the tree dies.
Not enough resin without water.
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Bark beetles have reproduced explosively in recent years.
They attack ever larger areas faster and faster, leaving clear-cuts and devastation behind.
Forest owners and forest companies are unable to remove the "beetle wood" quickly enough.
In 2019 alone, the infested forest areas in North Rhine-Westphalia increased by a third -
as an area, the damage was as large as 1.5 times the urban area of Cologne (680 square kilometers).
In the federal territory, an area the size of the Saarland is infested.
The damaged wood can only be used for animal litter, chipboard or pallets.
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At the end of 2021 - according to the forecasts for NRW - almost all spruce stands in the state will be destroyed.
If the spruce is no longer there, the bark beetle moves on.
The engraver also feeds on pines, larches and Douglas firs.
Lately the beetles have been spreading to beeches and oaks.