ECOLOGICAL FUNCTIONING AND CLIMATE CHANGES
in Marseille
Three opportunities for SDSU undergraduate and graduate students
Subject 1): Soil carbon storage in Mediterranean forests: toward a precise evaluation
e-mail: thierry.gauquelin@imbe.fr; ilja.reiter@oamp.fr
Supervisors: Thierry Gauquelin (full professor Aix Marseille University); Ilja Reiter (Research engineer, CNRS)
Funding: ANR Sec-Prime2
Keywords: carbon storage, soil, Mediterranean, forests, climate change, tree roots
Summary
The total ecosystem carbon (C) stock is large and in dynamic equilibrium with its environment. On earth, three main reservoirs regulate the carbon cycle: the oceans with 38,000 Pg C, the atmosphere with 750 Pg C, and the terrestrial systems with 2,200 Pg C (IPCC, 1990). Carbon Capture and Sequestration (CCS) is the process of capturing carbon at its source and storing it before it is released into the atmosphere. CCS would then reduce the amount of CO2 emitted into the atmosphere despite the continued use of fossil fuels. Most world’s terrestrial C and N is contained in soil and especially in forest soils. Increasing CO2 concentration in the atmosphere could change the carbon storage in soil as suggested by the third assessment report from the intergovernmental panel of climate change (IPCC 2001). It has been underlined that increasing CO2 in the atmosphere could alone cause 350 to 890 Pg of carbon to accumulate in the terrestrial biosphere by 2100. Maintaining the capacity of soil to store carbon is then essential to enhance soil quality, sustain and improve the forest production and reduce the atmospheric CO2. However, the carbon stock in the biosphere remains highly uncertain, especially in forest environments, due to the methodological problems for its evaluation. In the O3HP experimental site, we propose that the student investigates this soil carbon stock. A wide trench will be carried out in the forest floor in order to investigate different forms of carbon in the different soil levels in close relation with vegetation and tree structure. The student will be supervised by a CNRS researcher, an AMU professor, and will also closely work with one technician from IMBE. He / she will acquire techniques related to pedology, plant ecology and chemical ecology. The student will benefit from the expertise of the team on this issue over the last twenty years and funding from an ANR-Sec Prime2 project. The student will benefit from the sampling system required for this study. The measurements will be carried at the O3HP site and in the laboratory and the main model species will be Downy Oak. The work to be conducted requires interdisciplinary training in ecology and/or biology, and/or chemistry.
For more information about the O3HP site and the funding project see http://www.francetvinfo.fr/france/rechauffement-climatique-une-equipe-de-chercheurs-du-cnrs-s-interesse-aux-chenes-blancs_1065745.html
https://o3hp.obs-hp.fr/index.php/en/research/projects/126-secprime-anr-blanc-2012-tabs
Subject 2): Intensification of water scarcity in a Mediterranean shrub ecosystem: impact on litter flammability through modification of litter chemistry
Litter plays a major role in fire risk as a fuel in terrestrial ecosystems. Its flammability is widely recognized to vary according to its physical traits while a few research has tackled the impact of litter chemistry on fire risk. Mediterranean species, and so their litter, feature important amounts of hydrocarbon-like metabolites in their plant material, issued from both primary metabolism (waxes) and secondary metabolism (terpenes). Under low litter humidity contents, these metabolites increase litter flammability own to their physical properties including a relatively low auto-ignition temperature and low flash points. Since production of these metabolites is significantly driven by water availability, intensification of water could modify litter flammability in these ecosystems, with a presumable exacerbation of their flammability.
e-mail: elena.ormeno-lafuente@imbe.fr
Supervisors: Elena Ormeno (research scientist CNRS)
Subject 3): Hydrocarbure emissions from Mediterranean species: ecophysiological benefits for plant communities
e-mail: elena.ormeno-lafuente@imbe.fr ; catherine.fernandez@imbe.fr; amelie.saunier@imbe.fr
Supervisors: Elena Ormeno (research scientist CNRS), Catherine Fernandez (Pr AMU), Amélie Saunier (PhD)
Funding: ANR Sec-Prime2 (http://secprime.imbe.fr/)
Keywords: Biogenic volatile organic compounds; chemical ecology; ecophysiology; allelopathy; defense metabolites.
Summary
On a global scale, biogenic sources (especially vegetation) are the main emitters of volatile hydrocarbons, and clearly outstrip anthropogenic sources, which only contribute to 10% of the total hydrocarbons in the atmosphere. These hydrocarbons – known as biogenic volatile organic compounds (BVOC) – are found both, in the plant tissues and in the atmosphere where they play many roles in the environment. Issued from plant secondary metabolism, BVOC protect the emitter species from abiotic and biotic pressures. Their impact on the formation of secondary pollutants and climate has also been proven through numerous studies conducted since the 80’. However, the effect of atmospheric BVOC on individuals featuring poor BVOC emissions remains to be explored. These metabolites, once transported through the atmosphere are partly deposited on vegetation, and can bring benefits to neighboring species or individuals through their antioxidant properties. In this context, the objectives of the present study are to: (1) test the ecophysiological response of low-emitting individuals (due to abiotic stresses) growing in a BVOC-enriched atmosphere; (2) assess this response under various abiotic stresses (heating and /or water scarcity). The student will be supervised by a CNRS researcher, an AMU professor, and will also closely work with two technicians, one master thesis student and one PhD student. He / she will acquire techniques related to plant ecology, ecophysiology and chemical ecology. The student will benefit from the expertise of the team on this issue over the last twenty years and funding from an ANR-Sec Prime2 project. The student will benefit from the sampling system required for this study which has been created in 2014-2015 in the laboratory. The experiments will be carried at the O3HP site and in the laboratory and the main model species will be Downy Oak. The work to be conducted requires interdisciplinary training in ecology and/or biology, and/or chemistry.
For more information about the O3HP site and the funding project see http://www.francetvinfo.fr/france/rechauffement-climatique-une-equipe-de-chercheurs-du-cnrs-s-interesse-aux-chenes-blancs_1065745.html
https://o3hp.obs-hp.fr/index.php/en/research/projects/126-secprime-anr-blanc-2012-tabs
For more information about the programs contact the following persons:
Equipe Diversité et Fonctionnement des Molécules aux Ecosystèmes
Institut Méditerranéen de Biodiversité et d’Ecologie UMR 7263 CNRS, 237 IRD.
Université d’Aix-Marseille
Centre Saint Charles – Case 4
Bâtiment Sciences Naturelles – 1er étage
3, place Victor Hugo
13331 Marseille Cedex 03
France
Prof. Catherine FERNANDEZ
Aix Marseille Université Institut Méditerranéen
de Biodiversité et d’Ecologie UMR CNRS 7263
Equipe « Diversité et Fonctionnnement :
des Molécules aux Ecosystèmes »
Campus St Charles Cases 4 3
place Victor Hugo
13331 Marseille cedex 3
Tel : +33(0)4-13-55-12-22
France
Responsable de l’équipe DFME de l’IMBE : www.imbe.fr
Institut Méditerranéen de Biodiversité
et d’Ecologie marine et continentale.