PhD position (non-OECD citizen) "Recovery of assemblages following catastrophic disturbance over a latitudinal gradient"
At: The Resource Ecology Group, Wageningen University, The Netherlands The Resource Ecology Group The Resource Ecology Group performs research and education in community ecology of large herbivores, with emphasis on their interactions with the vegetation. We consider aggregation levels ranging from plant part to ecosystem, with a geographical focus on Africa. The group has an outstanding international scientific status and all our graduate students face prosperous carrier outlooks. Within the general research field 'Sustainable management of natural resources' of Prof. S. de Bie, we now offer a PhD position for the period 1 October 2007 - 1 October 2011. PhD project The study focuses on the recovery of animal assemblages after disturbances (terrestrial invertebrate assemblages). We will set up a series of experiments over a latitudinal gradient with differences in scale and intensity of disturbance treatments. Preparation, data analysis, writing and thesis defence will be carried out at Wageningen University. Requirements Ecologist or biologist (MSc degree) with experimental experience in fieldwork. Experience in statistical data analysis. In possession of a driving licence. Candidates with a publication record are preferred. Renumeration A full-time position for 4 years. The stipend will be 1100 Euro per month when in the Netherlands and 700 Euro when in the country of fieldwork. The position is open for non-OECD citizens only. Information For a short project proposal contact Dr. Frank van Langevelde, tel.: +31 317 484750; email [EMAIL PROTECTED], or Prof Steven de Bie, email: [EMAIL PROTECTED] Application Send your application, including CV, before June 10 to [EMAIL PROTECTED] Summary "Recovery of assemblages following catastrophic disturbance over a latitudinal gradient" Disturbances have a critical effect on the structure of natural communities. Ecosystem recovery following catastrophic disturbances has been studied well over a range of ecosystems. So far, many studies have followed the effects of a natural catastrophe and monitored the recovery of ecosystems after this event. These studies are, however, mainly limited to specific sites under specific conditions as they compare a disturbed site with an undisturbed site, either the situation before the disturbance or an undisturbed site nearby. A lot of experiments have been done to investigate the recovery of ecosystems following disturbances in which the level of disturbance is varied. These experiments show that current theory struggle to predict this recovery. Many studies focused on a widely accepted generalization in community ecology that localized disturbances, such as treefall gaps, promote the coexistence of species having different resource use strategies and dispersal and competitive abilities. This hypothesis is known as the intermediate disturbance hypothesis. Recently, these studies found that the species composition of gaps was unpredictable even for pioneer tree species. Strong recruitment limitation appears to decouple the gap disturbance regime from control of tree diversity in tropical forest. This has lead to the formulation of the neutral theory. The cornerstone of this theory is the so-called functional equivalence of species. Rigorous testing of the hypothesis of the functional equivalence of species over environmental gradients is still lacking. Besides the question whether species traits determine the assemblage recovery following a disturbance, recovery might also depend on interactions with species that already recolonised the disturbed area. One way to test both the role of species traits and abundances in the trajectory of assemblage recovery following a disturbance is to analyse the change in the abundance - body mass relationships over time. This PhD project will systematically investigate the role of species traits in the recovery following disturbances, looking at competitive ability, dispersal ability and survival related to the abundance - body mass relationship. In the context of ecosystem recovery after disturbance and the role of species traits in the trajectory of this recovery over environmental gradients, the latitudinal gradient is relevant to study as over this gradient not only species richness changes, but also abundances of individual species and the traits of these species are predicted to change. Another reason to look at the latitudinal gradient with its subsequent biodiversity gradient is the so-called insurance hypothesis. According to this hypothesis, biodiversity insures ecosystems against declines in their functioning because many species provide greater guarantees that some will maintain functioning even if others fail. The PhD project will carry out carefully designed experiments over a latitudinal gradient to study the recovery trajectory following disturbances and look at the traits of the species that recolonise, their population dynamics and competitive interactions with other established species.
