© dpa
After a slight improvement in 2023, the condition of Berlin's forests has deteriorated again.
37 per cent of trees show significant damage, according to the Forest Condition Report 2024 presented by Climate Protection and Environment Senator Ute Bonde (CDU). A warning level was issued for 59 per cent. Only four per cent of the trees show no visible damage.
Significant damage means that trees have lost more than 25 per cent of their leaves or needles or that the tree crown is heavily yellowed - both can occur at the same time. According to the Senate Department, this is due to the recent dry and hot years and stagnating regeneration. However, environmental influences such as nitrogen input from agriculture and traffic-related emissions also play a role because they acidify the soil.For the report, random samples of the surrounding trees are examined at around 40 locations every summer. The condition of the pine trees has improved in comparison, with only 13 per cent of them still significantly damaged. The proportion of pines without visible crown damage has risen slightly to 7 per cent.
In contrast, the vitality of oaks - the most important deciduous tree species in Berlin - has been declining since 2020. 87 per cent of oaks show significant damage, while oaks without any damage could not be recorded at all. Based on 10,000 trees, 28 pines and 47 oaks are expected to die each year, according to the forest condition report. According to the report, the condition of other deciduous tree species has also deteriorated. The proportion with significant damage is at 80 per cent, a record high.As a result of climate change, more frequent dry periods, especially in spring, and summer heatwaves are to be expected, it says. This poses risks for the sensitive forest ecosystem, which must be minimised in the selection of tree species, origins, site suitability and through maintenance measures in order to create stress-tolerant and diverse mixed deciduous forests.
The Berlin Nature Conservation Association is also concerned about the report. The condition of Berlin's oak trees is particularly worrying. "Oaks are vital for many species of birds, beetles and butterflies and must therefore be preserved at all costs," said Rainer Altenkamp, first chairman of the state association. A concept is therefore needed to reduce the extraction of groundwater. In addition, the fragmentation of forest areas must be stopped as it promotes drought stress.