The role of population origin and microenvironment in seedling emergence and early survival in Mediterranean maritime pine (Pinus pinaster Aiton)

PLoS One. 2014 Oct 6;9(10):e109132. doi: 10.1371/journal.pone.0109132. eCollection 2014.

Abstract

Understanding tree recruitment is needed to forecast future forest distribution. Many studies have reported the relevant ecological factors that affect recruitment success in trees, but the potential for genetic-based differences in recruitment has often been neglected. In this study, we established a semi-natural reciprocal sowing experiment to test for local adaptation and microenvironment effects (evaluated here by canopy cover) in the emergence and early survival of maritime pine (Pinus pinaster Aiton), an emblematic Mediterranean forest tree. A novel application of molecular markers was also developed to test for family selection and, thus, for potential genetic change over generations. Overall, we did not find evidence to support local adaptation at the recruitment stage in our semi-natural experiment. Moreover, only weak family selection (if any) was found, suggesting that in stressful environments with low survival, stochastic processes and among-year climate variability may drive recruitment. Nevertheless, our study revealed that, at early stages of recruitment, microenvironments may favor the population with the best adapted life strategy, irrespectively of its (local or non-local) origin. We also found that emergence time is a key factor for seedling survival in stressful Mediterranean environments. Our study highlights the complexity of the factors influencing the early stages of establishment of maritime pine and provides insights into possible management actions aimed at environmental change impact mitigation. In particular, we found that the high stochasticity of the recruitment process in stressful environments and the differences in population-specific adaptive strategies may difficult assisted migration schemes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Geography
  • Kaplan-Meier Estimate
  • Logistic Models
  • Mediterranean Region
  • Odds Ratio
  • Pinus / genetics
  • Pinus / growth & development*
  • Population Dynamics
  • Seedlings / genetics
  • Seedlings / growth & development*
  • Time Factors

Grants and funding

This work was supported by the Spanish Ministry of Science and Innovation through grant CGL2008-04503-C03-01/03, the Spanish National Institute for Agricultural and Food Research and Technology (grant RTA2010-00120-C02-02) and REMEDINAL2 (CAM, S2009/AMB-1783). NVP was supported by fellowship FPI-MCI (BES-2009-025151). SCGM acknowledges the support of a Senior Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-328146). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.