Drought and bark beetles threaten Styria’s spruce forests

Drought and an increase in bark beetle infestations are threatening forests in Styria, with spruce stands particularly affected, ORF reported. The economic damage to forest owners remains unclear.

Spruce trees are suffering especially from the lack of water because their shallow roots cannot reach water deeper in the soil, said Florian Hacker, a district forester at the Southeast Styria district authority.

Water stress makes the trees more vulnerable to bark beetles. The insects disrupt the tree’s supply of nutrients and water, causing its needles to fall, Hacker said. Almost all spruce stands now show signs of infestation.

State forestry director Michael Luidold said the beetle’s development is particularly favourable at temperatures of up to 30 degrees Celsius. A full assessment will only be possible at the end of September, when damaged areas can be clearly identified by the red spruce trees.

Deciduous trees are coping better with the drought. They end their growing season earlier, which reduces growth, but limits the damage and allows them to regenerate if rainfall is sufficient next year, Luidold said.

Resilient mixed deciduous stands now make up 30 percent of Styria’s forests, while pure spruce forests continue to decline.