A study by the University of Freiburg reveals that forest dieback poses a serious but underestimated threat to drinking water quality, especially during periods of drought such as those experienced in Germany between 2018 and 2020. Forests naturally filter nitrates from groundwater and cover 43% of German water protection areas. However, severe tree loss, particularly of Spruce and Beech, has weakened this function. In areas with over 25% forest loss, nitrate levels in groundwater increased by over 100%, rising from an average of 5 mg/L to 11 mg/L. While not all affected areas showed immediate changes, the study warns that long-term impacts may emerge. The researchers are calling for further investigation and stronger protection measures.
