Surveillance, Tracking, or Keeping an Eye on Someone or Something's Activities. - The 2024 period holds some optimism for the wellbeing of Bavarian forests.
How lush are the tree canopies? Are they filled with mistletoe? Do they produce a lot of cones? Around 17,000 trees in Bavaria were examined by specialists in July and August to assess their health. The findings will be shared in the Bavarian Parliament by the end of the year, as per Wolfgang Stoeger from the Bavarian State Forestry Institute in Freising. He mentions, "After several dry summers, we hope that the spring rainfall has slowed down the decline a bit."
Every year, this assessment, known as the forest health check, is conducted as a result of the 1980s forest decline. The 2023 report revealed that only approximately 12% of all forest trees in Bavaria showed no visible signs of drought or heat damage, setting an all-time low. In 2022, it was still 28%.
The challenges for this year's assessment are noteworthy, as Wolfgang Stoeger and his colleague Michael Heym explain. They are responsible for the forest health check. The excess heat and drought impacts are more evident in the subsequent years. Although this year's abundant rainfall has provided nature some respite, already affected trees may not recover quickly.
Undercover Tree Evaluations
For the forest census, forest experts search for around 17,000 trees at approximately 450 sites across the state each year. These sites were selected randomly in the 1980s. "We operate secretively," Stoeger explains. Forest owners are unaware that their trees have been selected to avoid situations like a forest owner intentionally removing a damaged tree.
Since marked trees cannot be found again, the selected trees cannot be tagged. Instead, the authority employs a trick: At the selected sites, a 30-centimeter metal rod is inserted into the ground. The location is marked on maps, and the surrounding trees are described in detail for the experts to inspect.
Michael Heym and Wolfgang Stoeger are currently in a forest plot near Niederaichbach (Landkreis Landshut). They inspect around 5 to 10% of the survey points to confirm the experts' findings based on the random selection principle. Heym uses a metal detector to search for the metal rod. Once it beeps, they locate it.
Transition to Mixed Forest
This forest is home to beeches, oaks, birches, pines, and spruces. According to Stoeger, this is an ideal mixed forest. Through telescopes, they observe the tree canopies and record the results in tables. The estimated number of cones or beech nuts, as well as needle loss, brown spots, or possible bark beetle infestation, are as important as damage caused by storms or snow breakage is recorded. Thankfully, destructive pests are not rampant here.
Stoeger points out that the fir suffered significantly in the 1980s. However, its condition has improved consistently since then. Today, pines and spruces face numerous difficulties due to heat and drought. "Germany should actually be a beech country," he concludes. A consequence of climate change is the change in forests, meaning the cultivation of more drought-resistant species. Fifty years ago, broad-leaved trees made up around 20% of Bavarian forests; now, it's almost 40%. "We must move away from monocultures and toward mixed forests."
Forest Health Check
The tree canopies in the mixed forest, filled with beeches, oaks, birches, pines, and spruces, are carefully inspected by experts for signs of damage or infestation, with a specific focus on the tree crowns. Despite the improvements in the condition of the fir trees since the 1980s, pines and spruces are currently facing challenges due to heat and drought, affecting their tree crowns significantly.
