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Homepage Etienne Klein


Researcher (DR), Dept. Forest, Grassland and Freshwater Ecology (EFPA).

INRA - Unité Biostatistique et Processus Spatiaux (BioSP, UR546)
Domaine St-Paul - Site Agroparc
84914 Avignon Cedex
Tél.: + 33 4 32 72 21 54
Fax: +33 4 32 72 21 82

Email: etienne.klein@inrae.fr
Phone: +33 4 32 72 21 54
Address: INRA - BioSP - Site Agroparc - 84914 Avignon Cedex 9 - France

Also associated to the unit Ecology of Mediterranean Forests.


I conduct interdisciplinary research on plant dispersal (pollen and seeds), at the crossroads of biostatistics and population biology. Estimating dispersal kernels in various experimental designs, understanding the impacts of long distance dispersal and modelling gene flow in mosaic landscapes are my main research topics. During my PhD, I worked on transgene escape in agro-ecosystems. I now mostly work on gene flow in forest species, particularly focusing on the estimation of dispersal kernels and components of male/female fertilities from multi-locus genetic data (typically microsatellites).

Mating systems in forest trees - estimating pollen and seed dispersal from microsatellites

Long distance dispersal and colonisation

SGS in an expanding population

Gene flow in mosaic landscapes

Pollen dispersal in crop species and consequences for GM escape


PhD students: Celine Devaux, Gwendal Restoux, Julien Fayard, Florence Carpentier, Julie Gaüzère,  

Postdocs: Tonya Lander, Emily Walker

The ExpandTREE ANR project will focus on ecology and population genomics questions inexpanding populations of Cedrus atlantica and Juniperus turbinata (2014-16, collaboration with Cristina Garcia, CIBIO Porto, and Pedro Jordano, CSIC Sevilla, et al.)

Catherine Larédo (MIA Jouy-en-Josas), Pierre-Henri Gouyon (MNHN, Paris) and Claire Lavigne supervised my PhD. Frédéric Austerlitz supervised my M.Sc. thesis on coalescence and we collaborated on numerous projects the years after.


Full list available on Google Scholar or ResearchGate

Roques, L., Garnier, J., Hamel, F., Klein, E.K. (2012) Allee effect promotes diversity in travelling waves of colonization. PNAS. 109: 8828-8833

Lander, T.A., Klein, E.K., Stoeckel, S., Mariette, S., Musch, B., Oddou-Muratorio, S. (2013) Interpreting realized pollen flow in terms of pollinator travel paths and land-use resistance in heterogeneous landscapes. Landscape Ecology. 28: 1769-1783.

Klein, E.K., Lavigne, C., and P.H. Gouyon. 2006. Mixing of propagules from discrete sources at long distance : comparing a dispersal tail to an exponential. BMC Ecology. 6:3

Fallour-Rubio, D., Guibal, F., Klein, E.K., Bariteau, M. & Lefèvre, F. (2009) Rapid changes in plasticity across generations within an expanding cedar forest. Journal of Evolutionary Biology. 22: 553-563.

Fayard, J., Klein, E.K., Lefèvre, F. (2009). Long-range dispersal and the fate of a gene from the colonization front. Journal of Evolutionary Biology. 22: 2171-2182.[3]

Nathan R., Klein E.K., Robledo-Arnuncio J.J., Revilla E. (2012) Dispersal kernels dans Dispersal and Spatial Evolutionary Ecology (Clobert, J., Baguette, M., Benton, T., Bullock, J., éditeurs)

[2] Kremer, A., Ronce, O., Robledo-Arnuncio, J.J., Guillaume, F., Bohrer, G., Nathan, R., Bridle, J., Gomulkiewicz, R., Klein, E.K., Ritland, K., Kuparinen, A., Gerber, S., Schueler, S. (2012) Long distance gene flow and adaptation of forest trees to rapid climate change. Ecology Letters. 15: 378-392.

[1] Robledo-Arnuncio, J.J., Klein, E.K., Muller-Landau, H.C., Santamaria, L. (en cours). Space, time and complexity in plant dispersal ecology. Movement Ecology

Klein, E.K., C. Lavigne, X. Foueillassar, P.H. Gouyon, C. Larédo. 2003. The corn pollen dispersal: mechanistic models and field experiments. Ecological Monographs. 73 : 131-150.

Klein, E.K., C. Lavigne, H. Picault, M. Renard, and P. H. Gouyon. 2006. Pollen dispersal of oilseed rape: estimation of the dispersal function and effects of field dimension. Journal of Applied Ecology.43:141-151

Lavigne, C. Klein, E.K., Mari, J.F., Le Ber, F., Adamczyk, K., Monod, H., & Angevin, F. (2008). Relative impacts of closest fields and background pollen on GM impurity rates in non-GM harvests. Journal of Applied Ecology. 45: 1104-1113

Chifflet R., Klein, E.K., Lavigne, C., Ricroch, A., Lecomte, J., Vaissière, B. (2011) Quantifying the spatial scale of pollen dispersal by insects in a landscape. Journal of Applied Ecology. 48: 689-696

Lander, T.A., Klein, E.K., Stoeckel, S., Mariette, S., Musch, B., Oddou-Muratorio, S. (2013) Interpreting realized pollen flow in terms of pollinator travel paths and land-use resistance in heterogeneous landscapes. Landscape Ecology. 28: 1769-1783

Austerlitz, F., C.W. Dick, C. Dutech, E.K. Klein, S. Oddou-Muratorio, P.E. Smouse, et V.L. Sork. 2004. Using genetic markers to estimate the pollen dispersal curve. Molecular Ecology. 13 : 937-954

Oddou-Muratorio, S., E. K. Klein, and F. Austerlitz. 2005. Pollen flow in the wildservice tree, Sorbus torminalis (L.) Crantz. II. Pollen dispersal and heterogeneity in mating success inferres from parent-offspring analysis. Molecular Ecology.14 : 4441-4452

Klein, E.K., Desassis, N., Oddou-Muratorio, S. (2008) Pollen flow in the wildservice tree, Sorbus torminalis (L.) Crantz. Whole inter-individual variance of male fecundity estimated jointly with dispersal kernel. Molecular Ecology. 17: 3323-3336

Klein, E.K., Carpentier, F.H., Oddou-Muratorio, S. (2011) Estimation of the whole variance of male fecundity from genotypes of progeny arrays: accuracy and limits of the Bayesian forward approach. Methods in Ecology and Evolution. 2: 349-361

Gaüzère, J., Klein, E.K., Oddou-Muratorio, S. (2013) Ecological determinants of mating system within and between three Fagus sylvatica populations along an elevational gradient. Molecular Ecology. 22: 5001-5015

Klein, E.K., Bontemps, A., & Oddou-Muratorio, S. (2013). Seed dispersal kernels estimated from genotypes of established seedlings: does density-dependent mortality matter? Methods in Ecology and Evolution. 4: 1059-1069


INRAE Researcher since 2003

Assistant professor in statistics, AgroParisTech (1999-2003)

PhD Student, department Ecology, Systematics & Evolution, University Paris-Sud Orsay (1996-1999)

Master "Stochastic and Statistical Modeling" , University Paris-Sud Orsay, 1995

Ecole Polytechnique, Palaiseau, 1992-1994


Fat-tailed dispersal kernels were known to behave qualitatively differently than thin-tailed dispersal kernels concerning the speed of advance of a colonization wave (Mollison 1977, Clark et al 2001). We proved that the exponential tails are also a critical point concerning the mixture of propagules from different sources: fat-tailed kernels lead to even propagule clouds when far from the sources, whereas propagule clouds become dominated by the closest source for thin-tailed kernels. The consequences of this property for the spatial pattern of genetic diversity during colonization were investigated during the PhD of Julien Fayard (collaboration with François Lefèvre) and within the ColonSGS ANR project (2008-2011).

Recent advances from Jimmy Garnier, Lionel Roques et al. have used a mathematical approach (theoretical results on reaction-diffusion equations) to investigate the propagation of diversity in a colonisation front. A promising approach with several expected results in the next future…

I investigate these questions in tight collaboration with Sylvie Oddou-Muratorio. We extended the likelihood approaches for neutral markers previously used for estimation of selection gradients (Burczyk et al 2002) to estimate explicit dispersal kernels and investigate the shape of their tail. The approach was originally designed on Sorbus torminalis, and for this species the approach provided results quite consistent with those from the now classical TwoGener approach (Smouse et al 2004). With Pierre Gérard, we extended the method to account for genotyping errors typical of microsatellites (± 2bp) for a study on hybridization between two Fraxinus species. Finer characterizations of the composition of pollen clouds and how they depend on the spatial pattern of individuals around a mother tree are also of interest. This could lead to alternative spatial mating models no more based on a dispersal kernel. These topics were central in the PhD of Florence Carpentier (collaboration with Joel Chadoeuf) and Gwendal Restoux (collaboration with Bruno Fady).

In her PhD thesis,  investigated the relations between long distance pollen flow and local adaptation in natural populations of Fagus sylvatica along an altitudinal gradient (collaboration with Sylvie Oddou-Muratorio). This question is also central in the MECC ANR project (2013-2017)

During my PhD, we estimated the dispersal kernel of oilseed rape and maize from experimental fields with marked plants in the middle. We proposed a method to analyse data from such experiments accounting explicitly for the spatial design. Actually, it consisted in estimating a dispersal kernel using an inverse method such as that used for seed dispersal (Ribbens 1997, Tufto 1997, Clark 1998).

For oilseed rape the estimated kernel was used in the GeneSys model (Colbach et al 2001) to forecast transgene escape in spatially explicit agronomical landscapes. During her PhD Celine Devaux estimated a dispersal kernel directly at landscape scale using microsatellites data and a statistical approach derived from those used on forest species. She found much fatter tailed kernels than those found at field scale.

For maize, the statistical approach we used quasi-mechanistic kernels, accounting for wind speed, main wind direction and difference of height between ears and panicles. The integration of this dispersal model with a model for flowering phenology was achieved within the MAPOD model that allows forecasting pollen flow within a spatially explicit corn landscape and an explicit meteorological scenario.

More recent works on gene flow in mosaic landscapes have focused on (i) pollinator travel path and mating patterns of Prunus avium and (ii) codling moth movements among apple orchards in a mosaic landscape (postdoc of Emily Walker in collaboration with Lionel Roques and Pierre Franck, PEERLESS project).


  • Mixed Effects Mating Model

Programs to analyse pollen dispersal from microsatellite data following the approach developed in Klein et al. 2008 are available upon request.