Master Thesis

Waldquellen: Jungwuchs nutzt Stickstoff nach Rodung

Marius Harmansa (11/2022-05/2023)

Support: Carl Beierkuhnlein, Frank Weiser

Northern Franconian forest springs are important contributors to regional biodiversity, but their catchment areas are facing deforestation due to drought and insect calamities driven by climate change. The hydrological attributes of spring water are closely related to their catchments, making the catchment area approach suitable for examining spring processes. This study aims to investigate whether deforestation of the catchment area can affect spring vegetation by increasing nitrogen in the spring water and subsequently, increasing nitrogen-demanding plant abundance. Our results suggest that the pH value, spring height, tree cover (straight above the spring vegetation), and cadmium yield in the water have the most significant impact on spring vegetation. Contrary to the hypothesis, there is not only no positive relationship between cut catchment area and nitrogen yield in the spring water, but a trend to the opposite. This suggests that the higher light regime of the catchment area reinforces understory plant growth in such a manner, that the understory plants act as a nitrogen buffer, holding the nitrogen back in the catchment area. Overall, this study highlights the importance of understanding the complex relationships between catchment area, spring water attributes, and vegetation to better manage and conserve these valuable ecosystems in the face of climate change.