A team from the Institute of Forest Sciences at the University of Freiburg shows that the extraction of ground water for industry and households is increasingly damaging floodplain forests in Europe given the increasing intensity and length of drought periods in the summer. The scientists have published their results in the journal Frontiers in Forests and Global Change.
Floodplain forests dominated by oaks are among the most at risk in Europe. Through conversion to arable land and pastures, as well as settlements, they have lost most of their original distribution. River regulation and drainage have also changed the natural hydrologic balance. The introduction of pests and diseases decimates native tree species such as elm and ash. At the same time, these forests play an important part in the control of flooding and protection of biodiversity.
The root of the study by the Freiburg team was the observation that the vitality of old trees in the oak forests of the Rhine valley had significantly declined, and their mortality appeared to have markedly increased. Forest ecologist Prof. Dr. Jürgen Bauhus’ work group then investigated whether these trends could also be discerned from the growth patterns of trees and whether they were connected with the widespread extraction of ground water for industry and households. Pumping water can reduce the groundwater level so far that even deep-rooted oaks cannot reach it.
Source: Floodplain forests under threat