Date : 02/02/2010

Laboratory
Laboratoire Ecologie, Systématique & Evolution UMR CNRS 8079
Bat 362, Université Paris Sud, 91405 Orsay
Director : Pr Paul Leadley

PhD Supervisor
Franck Courchamp
email : Cet e-mail est protégé contre les robots collecteurs de mails, votre navigateur doit accepter le Javascript pour le voir
phone : +33 169155685

Subjects / Tools-Methodologies

1 : Ecology/Modelling
2 : Climate change/Lab and field experiments
3 : Biological invasions/artificial ant colonies

Website : http://www.ese.u-psud.fr/

Summary of lab's interests

The ESE Lab is a large, multi-disciplinary Department whose members conduct research and teaching in areas ranging from evolution to ecology (including genetics, biomathematics, ecophysiology, population biology, systematics and biodiversity conservation). By all criteria this is a thriving research and teaching Institution, which has consistently received excellent ratings by both the CNRS and the University in the context of their independent quadrennial evaluations. It also was awarded in 2009 the maximum of four A+ on all four evaluation criteria by the AERES. The Laboratory occupies more than 3300 m2, in two buildings on the University Paris XI Orsay Campus, to which are associated greenhouses and semi-natural mesocoms. ESE consists of over 120 staff, about a quarter of which are graduate students studying for Ph.D. degrees. Annual research grant income is currently over 400 kÄ and in addition, members of ESE hold currently nearly 20 research grants. Information about ESE Laboratory: http://www.ese.u-psud.fr/

Summary of project

Among the many dreaded effects of global warming is the facilitation of new biological invasions by alien species in regions were cold climates are no longer an obstacle to establishment and spread. The introduction of alien species in new ecosystems is considered to be the second largest threat to biodiversity. Nearly half the extinction events that have occurred in the last 400 years were caused by biological invasion. Beyond the mere extinction of numerous species, the introduction of non-native animal species causes colossal economic losses. Because shifts in climatic conditions are likely to open new habitats to species that were hitherto hindered in their colonisation by cold weather, biological invasions need to be studied in the context of global warming. In particular, global climatic change is predicted to increase average temperatures on the planet, and thereby to allow access of temperate regions to subtropical and tropical species, especially of insects and other cold-blooded organisms. We focus on a biological taxonomic group that gathers a number of important and unique features in the present context: ants. Over 12 000 ant species have already been described and an estimated 22 000 species exist worldwide. It is estimated that 15-20% of the terrestrial animal biomass is made up of ants. Their high adaptive capacities make ant extraordinarily successful colonizers and they are now among the most damaging invasive species on the planet. In general, invasive alien ants totally destroy much of the fauna and flora of invaded ecosystems, killing even very large animals. Doing so, they may hinder the proper functioning of the entire ecosystem, thereby lowering the efficiency of ecosystem services. Ants are also extremely difficult to control as invasive species. There are already 47 ant species recorded as alien in Europe, but only six of them are considered as invasive so far, mostly in the south were mild temperatures allow winter survival. The climatic limitations imposed upon invasive ants in Europe will likely soften in the coming years, which could dramatically increase the number of invasive ants. In order to assess which species are the most likely to be problematic, we will use a multi-approach methodology. We will start by a thorough literature search in order to perform a meta-analysis of the criteria best describing the likeliness of ant invasion success. This will allow to systematically define the whole set of ant species characterised by a number of ecophysiological and invasion-related life history traits. This will be completed by a mathematical model allowing to project which exotic ant species could see favourable abiotic conditions emerge in Europe following global warming. This model will be based on already available spatial SIG maps of predicted annual temperatures (eg IPPC data). The third step will focus on the most likely invasive species, as revealed by the two steps above, to experimentally determine parameters such as critical lower and higher temperatures, water loss and cuticular evapotranspiration, activity loss or social behaviour disruption and metabolic rates for example. The fourth step will account for the biotic component of ecosystem resistance to invasion, focussing on the local ant community. In particular, we will set up classical dominance matrix experiments, putting in regard the most concerning exotic species with major components of the local myrmecofauna, in order to establish competitive/dominance relationships among local and exotic species. We will also perform experimental establishment of invasive species in different competitive settings. This will allow to assess which potentially invasive ant species have the potential to overcome the local ant species. This whole set of approaches will allow to model in a predictive way the different scenarios of invasions of Europe by the most ìat-riskî exotic ant species which are likely to exert the highest impact on local ecological communities.