The significance of nitrogen uptake and metabolism by beech roots for the competition for
nitrogen in the rhizosphere
Project description
This project is aimed (1) to quantify the uptake of inorganic and organic nitrogen sources by beech
roots and to elucidate the competition between beech roots and soil microorganisms for the
nitrogen sources, (2) to analyse the mechanisms of competition, and (3) to characterise their
dependency on environmental factors, particularly on drought, in natural beech regeneration of
nitrogen-limited, beech-dominated deciduous forests on calcareous soil. For this purpose the
physiological principles and patterns of competition between beech and soil microorganisms will be
studied in experiments under field conditions and in the greenhouse. In the field, short-term and
long-term consequences of differences in water availability will be analysed in microcosms
exchanged between a cool/moist (NE aspect) and a warm/dry (SW aspect) slope. Under controlled
conditions, the significance of colonisation of beech roots with mycorrhiza fungi for the uptake of
inorganic and organic nitrogen will be quantified at different levels of water availability and different
temperatures. These studies include the determination of uptake rates and uptake kinetics of NH4+
and NO3-, and amino compounds combined with N metabolite profiling in beech roots.
Contact:
Prof. Dr. Heinz Rennenberg
Phone: +49 761 203 8300
Email: heinz.rennenberg@ctp.uni-freiburg.de
Dr. Judy Simon
Phone: +49 761 203 8309
Email: judy.simon@ctp.uni-freiburg.de
Project duration:
Project start:
Project end:
01/06/2010
31/05/2013
Project leader:
Heinz Rennenberg
Chair of Tree Physiology
Institute of Forest Sciences
Georges-Köhler-Allee 53/54
79110 Freiburg i. Br., Germany
Phone: +49 (0)761 203 8300
Fax:
+49 (0)761 203 8302
Email: heinz.rennenberg@ctp.uni-freiburg.de