Postdoctoral position :

Interpretation of stable isotope patterns in tree rings for assessing
the responses of beech forests to long-term environmental changes

Location : Forest Ecophysiology Unit, National Institute of Agronomical
Research (INRA-Nancy), France

In the framework of the EU Research Training Network "Ecophysiology in
Closing Terrestrial CARbon Budget" (NETCARB, see, a postdoctoral position is
opened at the INRA, Nancy (France).


The general goal of the project is to study long-term changes in water,
carbon and nitrogen metabolisms in beech (Fagus sylvatica) under
environmental changes using stable isotopes (13C, 15N and possibly 18O)
in tree rings. Two steps will be considered : (i) a better
understanding of causes of 15N variations in tree-rings, based on the
analysis of sites where nitrogen (labelled or not) was experimentally
added. (ii) the study of long-term changes in 13C, 15N and possibly 18O
in tree rings in order to compare present isotopes abundances with
XIXth century levels, taking into account age effects. These isotopic
trends will be related to long-term radial growth variations.

Methods and facilities:

Fieldwork for tree sampling will have to be carried out at different
steps of the project. Dendrochronological techniques will be used for
tree growth analysis and rings dating. Isotopic measurements will be
carried out with the Nancy spectrometer facilities. Some laboratory
work will be needed for wood cellulose or nitrogen compounds
extraction. Existing bioclimatic models (water balance) will be used to
interpret the data.

Requested expertise and training:

Candidates should possess some expertise in some or all of the previous
technical and scientific fields, at the PhD level. In the framework of
the training program, the needed complementary expertise will be
provided at INRA Nancy or during the European NETCARB summer schools.

Salary and citizenship:

Net monthly salary is 2200 euros. Applicants must be EU citizens or of
an EU Associated State, or have been residents in any of the EU states
for at least 5 years. Applicants should not be French citizens.

Start and duration:

2-yr position with start date negotiable, but preferably starting
between April  and September 2001. Review will begin March 2001 and
continue until position is filled.

Applications should be sent at the earliest convenience to Dr.
Jean-Marc Guehl, to the following address. Curriculum vitae, summary of
research experience and the names, addresses and phone numbers of two
academic referees, should be included.


Jean-Marc Guehl or Jean-Luc Dupouey

Forest Ecophysiology Unit


F-54280 Champenoux

tel. 00 33 3 83 39 40 36

fax. 00 33 3 83 39 40 41

mail: [log in to unmask] or [log in to unmask]

More information on NETCARB can be found at:

Jean-Marc Guehl, Unite Ecophysiologie Forestiere, INRA Centre de Nancy
54280 Champenoux, France, tel (33) 3 83 39 40 36, fax (33) 3 83 39 40 69