© 2016 biological interactions

Department of Botany and Zoology

STELLENBOSCH UNIVERSITY

biological interactions

Christopher Bosc

PhD student with A.C. Pauw

I grew up in a village near Pyrenean Mountains in France. It’s in this rural context that my interest for insects and more generally nature emerged. Later, I moved to Toulouse (France) to attend Paul Sabatier University and begin studies in biology and ecology. I graduated from Paul Sabatier University with a BSc in Organisms, Populations and Ecosystems Biology in June 2009, then with an MSc in Biodiversity, Ecology and Evolution in June 2011. During my MSc years, I realized internships at the laboratory of functional ecology (Ecolab) in Toulouse, where I studied the aquatic invertebrate communities of tank-bromeliads from French Guiana, under the direction of Regis Céréghino. Then, I graduated with a second MSc in Modelling of Ecological Systems in June 2012, still from the Paul Sabatier University. During this MSc, I realized an internship at the Institute of Evolution Sciences (ISEM) in Montpellier (France) under the direction of Sonia Kéfi and Nicolas Mouquet, where I studied the role of abiotic facilitation between plants on the functioning and the stability of an ecosystem, by using a mathematical model.

About

Most eukaryote species on earth are terrestrial arthropods, representing more than 80% of all animal species. However, despite their ubiquity, the assembly rules and processes that structure arthropod communities are poorly known.

Thus, the overall aim of my thesis will be to see how arthropod communities and their interactions with plants are affected by different perturbations, namely fire and bird extinction in fynbos. For that purpose, I will conduct samplings of plants and arthropods in natural ecosystems in the Jonkershoek valley, which is situated in the Jonkershoek nature reserve and dominated by fynbos-type vegetation. I will notably attempt to answer these questions:

To what extent fire changes the diversity, abundance and composition of arthropods and plants? What functional traits are important in determining the response of arthropods and plants to fire? How plant/arthropod trophic networks change during post-fire successions?

The question of the control of arthropod populations (Top-down vs Bottom-up control) will also be assessed: Does the loss of bird predation precipitate an ecological cascade in which arthropod populations explode (Top-down control)? Does plant composition explain more arthropod composition and diversity than bird presence/absence does (Bottom-up control)?

Current Research

Régis Céréghino, Céline Leroy, Jean-François Carrias, Laurent Pelozuelo, Caroline Ségura, Christopher Bosc, Alain Dejean, Bruno Corbara. (2011) Ant-plant mutualisms promote functional diversity in phytotelm communities. Functional Ecology. 25, 954–963.

Publications