Get access

Spatial genetic structure in continuous and fragmented populations of Pinus pinaster Aiton

Authors

  • A. I. DE-LUCAS,

    1. Departamento de Producción Vegetal y Recursos Forestales, E.T.S. Ingenierías Agrarias, Universidad de Valladolid, Avenida de Madrid 44, E-34004 Palencia, Spain
    Search for more papers by this author
  • S. C. GONZÁLEZ-MARTÍNEZ,

    1. Departamento de Sistemas y Recursos Forestales, CIFOR-INIA, Carretera de La Coruña km 7.5, E-28040 Madrid, Spain
    Search for more papers by this author
  • G. G. VENDRAMIN,

    1. CNR Istituto di Genetica Vegetale, Sesto Fiorentino, Firenze, Italy
    Search for more papers by this author
  • E. HIDALGO,

    1. Departamento de Producción Vegetal y Recursos Forestales, E.T.S. Ingenierías Agrarias, Universidad de Valladolid, Avenida de Madrid 44, E-34004 Palencia, Spain
    Search for more papers by this author
  • M. HEUERTZ

    1. Departamento de Sistemas y Recursos Forestales, CIFOR-INIA, Carretera de La Coruña km 7.5, E-28040 Madrid, Spain
    2. Behavioural and Evolutionary Ecology, CP 160/12, Faculty of Science, Université Libre de Bruxelles, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium
    Search for more papers by this author

  • This work is part of A.I..d.-L.’s PhD on gene flow, demography and genetic diversity in maritime pine. S.C.G.-M. is working in population genetics and genomics of forest trees and conservation genetics of Mediterranean plants. G.G.V. is interested in conservation genetics, genetic structure studies and genomics of forest trees. E.H. is professor at the University of Valladolid, her research focuses on genetics of grapevine and forest trees. M.H. is interested in empirical and simulation studies of mating systems, gene flow and genetic structure in plants.

Ana I. de Lucas, Fax: +34979108302; E-mail: ailucas@pvs.uva.es

Abstract

Habitat fragmentation, i.e., the reduction of populations into small isolated remnants, is expected to increase spatial genetic structure (SGS) in plant populations through nonrandom mating, lower population densities and potential aggregation of reproductive individuals. We investigated the effects of population size reduction and genetic isolation on SGS in maritime pine (Pinus pinaster Aiton) using a combined experimental and simulation approach. Maritime pine is a wind-pollinated conifer which has a scattered distribution in the Iberian Peninsula as a result of forest fires and habitat fragmentation. Five highly polymorphic nuclear microsatellites were genotyped in a total of 394 individuals from two population pairs from the Iberian Peninsula, formed by one continuous and one fragmented population each. In agreement with predictions, SGS was significant and stronger in fragments (Sp = 0.020 and Sp = 0.026) than in continuous populations, where significant SGS was detected for one population only (Sp = 0.010). Simulations suggested that under fat-tailed dispersal, small population size is a stronger determinant of SGS than genetic isolation, while under normal dispersal, genetic isolation has a stronger effect. SGS was always stronger in real populations than in simulations, except if unrealistically narrow dispersal and/or high variance of reproductive success were modelled (even when accounting for potential overestimation of SGS in real populations as a result of short-distance sampling). This suggests that factors such as nonrandom mating or selection not considered in the simulations were additionally operating on SGS in Iberian maritime pine populations.

Get access to the full text of this article

Ancillary