Tree Genetics & Genomes

, Volume 7, Issue 1, pp 37–48

Effects of seed dispersal, adult tree and seedling density on the spatial genetic structure of regeneration at fine temporal and spatial scales

  • Fabrice Sagnard
  • Sylvie Oddou-Muratorio
  • Christian Pichot
  • Giovanni G. Vendramin
  • Bruno Fady
Original Paper

DOI: 10.1007/s11295-010-0313-y

Cite this article as:
Sagnard, F., Oddou-Muratorio, S., Pichot, C. et al. Tree Genetics & Genomes (2011) 7: 37. doi:10.1007/s11295-010-0313-y

Abstract

Several demographic factors can produce family structured patches within natural plant populations, particularly limited seed and pollen dispersal and small effective density. In this paper, we used computer simulations to examine how seed dispersal, density, and spatial distribution of adult trees and seedlings can explain the spatial genetic structure (SGS) of natural regeneration after a single reproductive event in a small population. We then illustrated the results of our simulations using genetic (isozymes and chloroplast microsatellites) and demographic experimental data from an Abies alba (silver fir) intensive study plot located in the Southern French Alps (Mont Ventoux). Simulations showed that the structuring effect of limited dispersal on seedling SGS can largely be counterbalanced by high effective density or a clumped spatial distribution of adult trees. In addition, the clumping of natural regeneration far from adult trees, which is common in temperate forest communities where gap dynamics are predominant, further decreases SGS intensity. Contrary to our simulation results, low adult tree density, aggregated spatial distribution of seedlings, and limited seed dispersal did not generate a significant SGS in our A. alba experimental plot. Although some level of long distance pollen and seed flow could explain this lack of SGS, our experimental data confirm the role of spatial aggregation (both in adult trees and in seedlings far from adult trees) in reducing SGS in natural populations.

Keywords

Seed dispersalSpatial genetic structureDensityDemographyTemperate forest treesForest dynamicsAbies alba

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Fabrice Sagnard
    • 1
    • 2
  • Sylvie Oddou-Muratorio
    • 1
  • Christian Pichot
    • 1
  • Giovanni G. Vendramin
    • 3
  • Bruno Fady
    • 1
  1. 1.INRA, UR629Ecologie des Forêts Méditerranéennes (URFM)Avignon cédexFrance
  2. 2.CIRADMontpellier cédex 5France
  3. 3.CNRIstituto di Genetica VegetaleSesto FiorentinoItaly