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• Location

UMR SILVA Université de Lorraine, AgroParisTech, INRAE
Université de Lorraine
BP 70239
54560 Vandoeuvre les Nancy -France -

Period: February 2024-July2024

Supervisor Caroline Plain caroline.plain@univ-lorraine.fr

• Project

Methane (CH4) is one the most important greenhouse gases, responsible for c. 20% of global warming (IPCC 2022). Forest soils are one of the main methane sinks. But tree stems can potentially be sources of methane emission to the atmosphere (Covey et al., 2016) and then reduce the methane sink when considering forest ecosystem. Various climatic and biotic constraints have led to the weakening of trees in recent years. These stresses will make them even more vulnerable especially to pests and diseases and possibly promote methane emissions from trees.

The influence of trees has been recognized as the largest source of uncertainty in the global methane budget (Saunois et al. 2020).

• Objectives of the intership

the aim of the project is to determine, in uplands, whether dying and dead trees emit more methane than healthy trees? Specifically, the objectives will be to determine whether excess methane is emitted by dying and dead trees compared to healthy trees, to quantify this excess emission, and to determine what are the key drivers of this excess emission. The key scientific questions are: (i) Are these drivers species-dependent or related to environmental conditions? (ii) Are higher methane emissions explained by an increase in methane production and/or by a facilitated transport of methane within stem? (iii) Can methane emission from tree stems be used as a proxy for early detection of pests and diseases leading to tree death?

• Experimental approach

Trees stem methane fluxes on dying, dead and healthy trees will be measured. Measurements will be performed on different species, at different dates and in different sites to determine if methane emissions are driven by tree phenology, meteorological and/or edaphic conditions.
The internship project is expected to make major advances on the role of dead and dying trees on methane emissions and thus provide a better estimate of the methane budget of forests.
The candidate will manage field campaigns and analyze the results.

Field experiments will sometimes be carried out on rugged sites with heavy equipment.