Acknowledgements:
The project was funded through Waldlabor Project Grant 4.20.P01 awarded to Marius Floriancic. We thank the Waldlabor Zürich (Martin Brüllhardt – www.waldlabor.ch) as well as the forest owner Jakob Heusser for their cooperation and support. We acknowledge support during data collection and laboratory work from the technical staff and student helpers working at the Waldlabor ecohydrology field site (Lena Straumann, Anna Lena Könz, Maria Grundmann, Lara Virsik, Elisa Hage, Stefano Martinetti, Fabian Strittmatter, Adrian Kreiner, Livio Steiger and Lucien Biolley). We thank Tracy Napitupulu and Björn Studer for isotope analyses and Annika Ackermann, Roland A. Werner and Nina Buchmann for sharing the cryogenic extraction laboratory.