Home page of David Claessen

Ecole Normale Supérieure

CERES-ERTI

Centre d'Enseignement et de Recherches sur l'Environnement et la Societé

Environmental Research and Teaching Institute

David Claessen

Maître de conférences - Assistant professor

E-mail:
Visiting address:	Ecole Normale Supérieure
	CERES-ERTI
	Room R14-2 (level 0)
	24 rue Lhomond / 8 rue Erasme
	75005 Paris
	How to get there
Tel:	+33 1 44 32 27 21
Fax:	+33 1 44 32 27 27
Maps:
Postal address:	Click here

Research interests

Ecology and evolution of physiologically structured populations - Dynamics of cannibalistic populations. Dynamics of small populations with phenotypically plastic life histories. Stochastic models of structured populations. Size-structured food web dynamics.

Adaptive dynamics - Stochastic population dynamics: the role of finite population size in evolutionary dynamics. Adaptive dynamics of size-structured populations

Linking abiotic factors and food web dynamics - A pivotal challenge to theoretical ecology is to make explicit the link between abiotic factors (eg climate) and the dynamics of ecosystems, relating physiological processes at the individual level, to food web responses including population-level feedbacks. Predicting the response of ecosystems to environmental change hinges on such theory. With large-scale experiments (at CEREEP, Foljuif) the theory will be put to the test using terrestrial and aquatic systems.

Ecological and evolutionary responses to human impact - The exploitation of living resources (fisheries, agriculture) imposes strong selection on populations, ranging from size-selective fisheries to the selection of resistant pathogens and agricultural pests, sometimes resulting in rapid evolutionary responses in target or non-target populations. At the same time, populations respond to environmental impact through phenotypically plastic responses (e.g., density-dependent individual growth). In the face of such adaptive and plastic processes, how can we sustainably exploit and manage living resources?

Simple models of climate/ecology feedback - What is the role of food web interactions in the feedback between climate and the oceanic plankton community? The idea is to extend simple ecological models of food web dynamics with a dynamical model of climate, allowing us to study the feedbacks between ecological and climate dynamics.

I am a member of the research team Eco-Evolutionary Mathematics of the Ecology and Evolution laboratory (UMR 7625)

Teaching
At CERES-ERTI:	Atelier "Modelisation: reserves marines" (Workshop "Modelling: marine reserves")
	Atelier "Modelisation: analyse des donnees" (Workshop "Modelling: data analysis")
	Atelier "Agriculture" 2007-2008: "Agriculture : comment et pourqoi reduire les pesticides?" (Workshop "Agriculture: why and how to reduce pesticides?")
	Atelier "Agriculture" 2006-2007: "Agriculture durable" (Workshop "Sustainable agriculture")
Master ENS (EBE):	Ecologie evolutive (E2), ENS Master 1 (Evolutionary ecology)
	Dynamique adaptative et coévolution : concepts et modèles (DYAD), EBE Master 2 (Introduction to adaptive dynamics theory)
	Ecologie et dynamique des populations structurées (STRU) , EBE Master 2, (Ecology and dynamics of structured populations)
	Lecture Ecological and evolutionary responses to human impact (PAB) , EBE Master 1, UPMC

See also the website of the Master program Ecologie, Biodiversité et Evolution (EBE) co-hosted by the universities Paris 6, Paris 11, AgroParisTech and the ENS

Publications

E Edeline, TO Haugen, FA Weltzien, D Claessen, IJ Winfield, NC Stenseth and LA Vollestad (2009) Body downsizing caused by non-consumptive social stress severely depresses population growth rate Proceedings of the Royal Society B doi:10.1098/rspb.2009.1724

Aguilee, R., D. Claessen and A. Lambert. (2009). Allele fixation in a dynamic metapopulation: founder effects vs refuge effects. Theoretical Population Biology 76(2): 105-117

Claessen, D., A. de Vos and A.M. de Roos. (2009). Bioenergetics, overcompensation and the source/sink status of marine reserves. Canadian Journal of Fisheries and Aquatic and Sciences 66(7): 1059-1071

Claessen, D., J. Andersson, L. Persson and A.M. de Roos. (2008). The effect of population size and recombination on delayed evolution of polymorphism and speciation in sexual populations. The American Naturalist 172(1):E18-E34

de Roos, A.M., T. Schellekens, T. van Kooten, K. van de Wolfshaar, D. Claessen and Lennart Persson (2008). Simplifying a physiologically structured population model to a stage-structured biomass model. Theoretical Population Biology 73: 47-62

de Roos, A.M., T. Schellekens, T. van Kooten, K. van de Wolfshaar, D. Claessen and Lennart Persson (2007). Food-dependent growth leads to overcompensation in stage-specific biomass when mortality increases: the influence of maturation versus reproduction regulation. American Naturalist 170(3): E59-E76

Andersson, J., P. Bystrom, D. Claessen, L. Persson and A.M. de Roos. (2007). Stabilization of population fluctuations due to cannibalism promotes resource polymorphism in fish. American Naturalist 169(6):820-829

Claessen, D., J. Andersson, L. Persson and A.M. de Roos. (2007). Delayed evolutionary branching in small populations. Evolutionary Ecology Research 9(1): 51-69

Claessen, D., C.A. Gilligan, P.J.W. Lutman and F. van den Bosch. (2005). Which traits promote persistence of feral GM crops? Part 1: implications of environmental stochasticity. Oikos 110 (1): 20-29.

Claessen, D., C.A. Gilligan and F. van den Bosch. (2005). Which traits promote persistence of feral GM crops? Part 2: implications of metapopulation structure. Oikos 110 (1): 30-42.

Gilligan, C.A., D. Claessen and F. van den Bosch. (2005). Spatial and temporal dynamics of gene movements arising from deployment of transgenic crops. Book chapter in J.H.H. Wesseler (Ed.) . Environmental Costs and Benefits of Transgenic Crops pp. 143-161.

Claessen, D. (2005). Alternative life-history pathways and the elasticity of stochastic matrix models. American Naturalist 165: E27-E35.

Claessen, D; de Roos, AM; Persson, L. (2004). Population dynamic theory of size-dependent cannibalism. Proc. Roy. Soc. B: Biol. Sci. 271 (1537): 333-340.

Persson, L; Claessen, D; De Roos, AM; Bystrom, P; Sjogren, S; Svanback, R; Wahlstrom, E; Westman, E. (2004). Cannibalism in a size-structured population: Energy extraction and control. Ecological Monographs 74 (1): 135-157.

Claessen, D; de Roos, AM. (2003). Bistability in a size-structured population model of cannibalistic fish - a continuation study. Theoretical Population Biology 64 (1): 49-65.

Persson, L; De Roos, AM; Claessen, D; Bystrom, P; Lovgren, J; Sjogren, S; Svanback, R; Wahlstrom, E; Westman, E. (2003). Gigantic cannibals driving a whole-lake trophic cascade. P.N.A.S. 100 (7): 4035-4039.

Claessen, D; Van Oss, C; de Roos, AM; Persson, L. (2002). The impact of size-dependent predation on population dynamics and individual life history. Ecology 83 (6): 1660-1675.

Claessen, D; Dieckmann, U. (2002). Ontogenetic niche shifts and evolutionary branching in size-structured populations. Evolutionary Ecology Research 4 (2): 189-217.

Vala, F; Weeks, A; Claessen, D; Breeuwer, JAJ; Sabelis, MW. (2002). Within- and between-population variation for Wolbachia-induced reproductive incompatibility in a haplodiploid mite. Evolution 56 (7): 1331-1339.

Claessen, D; de Roos, AM; Persson, L. (2000). Dwarfs and giants: Cannibalism and competition in size-structured populations. American Naturalist 155 (2): 219-237.

Claessen, D; de Roos, AM. (1995). Evolution of virulence in a host-pathogen system with local pathogen transmission. Oikos 74 (3): 401-413.

PhD thesis

Claessen, D. (2002). Dwarfs and giants - the dynamic interplay of size-dependent cannibalism and competition. PhD thesis University of Amsterdam. [ 3.7 MB ]

CERES-ERTI, Ecole Normale Supérieure, 24 rue Lhomond, 75320 Paris Cedex 05, tel 01 44 32 27 20
www.environnement.ens.fr