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Validation of critical limits for nitrogen of selected forest communities

Description of the project:
Today’s critical limits for nitrogen input in forests soils are merely based on expert assessment. Due to sustained high nitrogen inputs, these applied thresholds have to be revised. Thus, the aim of the project is to develop FFH habitat type and forest community specific thresholds for critical nitrogen inputs on the basis of an objective data basis. For this purpose, simultaneous surveys of vegetation data, site- and soil parameters as well as nitrogen deposition in selected nitrogen-sensitive forest communities in Baden-Württemberg are planned along a nitrogen deposition gradient. The assessment of the forest community specific nitrogen sensitivity therefore relies on the comparison between nitrogen availability and conversation status of the FFH habitat types. The latter is defined by the proportion of nitrophilic plants not belonging to the basic stock of FFH habitat types. Permanent above threshold nitrogen input to forest soils have various negative effects on: soil conditions (acidification and associated release of toxic aluminum ions and depletion of nutrients calcium, magnesium and potassium), forest nutrition (nutrient imbalance caused by nitrogen surplus), the composition of the forest soil vegetation (biodiversity) and water quality (nitrate output into surface and ground water). Site-specific knowledge about the maximum tolerable nitrogen input for different forest communities is essential in order to assess its damage potential to forest ecosystems functions.

contact person: Weiler M
Phone: -49(0)761/203-3535
Email: markus.weiler@hydrology.uni-freiburg.de
Start of project: 01.02.2017
End of project: 31.12.2019
Project Management:
Albert-Ludwigs-University Freiburg
Weiler M
Professur für Hydrologie

Friedrichstrasse 39
79098 Freiburg i. Br.

Phone: +49(0)761-203-3530
Fax: +49(0)761-203-3994
Email: hydrology@hydrology.uni-freiburg.de
Actual Research Report

  • Sucker C
  • FVA Freiburg, Land
    Stickstoff, Critical Limits, Waldgesellschaften