Stable isotopes of water are one of the most widely used tools to track the pathways of precipitation inputs from the canopy through soils to streams. In the past, soils have often been treated as black-boxes through which precipitation is routed to streams without much consideration of how, when, and where water is transported along soil water flow paths. In fact, precipitation reaches the forest floor via diffuse (throughfall) and point (stem flow) inputs and throughfall can be highly heterogeneous, partly as a result of variations in canopy coverage, tree stem and branch architecture.

The aim of this thesis is to use stable isotopes of water (2H and 18O) of an artificial stemflow labelling event with a deuterated isotope tracer to evaluate how fast and with which patterns stemflow infiltration can influence trees’ root water uptake. The study will be part of the DFG project “Using advances in stable water isotopy to quantify species- and interspecific ecohydrological feedback processes and water transit times of different tree stands” and will be conducted at forest stands near Ettenheim.

To track the precipitation isotopic input through the canopy into the soil an artificial stemflow labelling event will be conducted and monitored. Soil water and tree xylem isotope composition will be monitored continuously in-situ before, during and after the irrigation event. In addition, destructive samples of soils and tree xylem will be taken.

Dr. Natalie Orlowski

The date of the stemflow labelling will be dependent upon project requirements

Prof Markus Weiler: markus.weiler@hydrology.uni-freiburg.de; Tel. 0761 – 203 3535

Field work, lab work, statistics, interdisciplinarity, creativity

Deutsch/Englisch

will be provided