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Museu de Ciències Naturals
Passeig Picasso s/n, Barcelona
Lunes, 24 de Enero 2011.
12:00 am
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Gloria Luque
Postdoctoral Fellow.
Laboratoire d'Ecologie Systématique & Evolution de l'Université Paris-Sud, France
Allee Efects in social species: First results for an invasive ant
Allee Efects are recognized as an important process in population dynamics by which the per capita growth rate may decline with decreasing population size, due to the need of individuals aggregation or cooperation.
Despite the original proposition that they may be ubiquitous in social organisms, there are no studies of AE in eusocial insects. We identify two main problems that may explain the abscence of such studies: the appearence of the group as an intermediate level between the individual and the populations, and the composition of the colonies (queens and esterile workers).
We present the first results of a study of AE in an invasive ant species, the Argentine ant.
Cleo Bertelsmeier
PhD student.
Laboratoire d'Ecologie Systématique & Evolution de l'Université Paris-Sud, France.
Can they feel the heat?
Ant invaders have a huge impact on ecosystem functioning and biodiversity as well as on human estates and agroecosytems, where they incur high economic costs. Because of their small size, ants are easily transported all over the world by humans and have increasing opportunities to become invasive. Consequently, several ant species are among the 100 worst invasive species list issued by the IUCN. However, the successful establishment of a species in a new habitat and its potential to become invasive depend on many factors, including local climatic conditions.
My goal is to explore the effect of climate change on invasiveness because global warming is likely to favour invasions over the next century by enabling species from lower latitudes to colonize higher latitudes. For example, the Argentine ant Linepithema humile is invasive all around the Mediterranean sea, but has so far failed to invade further north, which could change as the European climate warms.
I am going to talk about three complementary approaches that I use in order to estimate ant invasion risks in a changing world: the use of characteristics of invasive ant species to predict future potential invaders, predictive modelling under a scenario of climate change and field experiments under different climatic conditions.
