Life after disturbance (I): changes in the spatial genetic structure of Jacaranda copaia (Aubl.) D. Don (Bignonianceae) after logging in an intensively studied plot in French Guiana

• Published in: Annals of forest science. Vol. 72; pp. 509 - 516
• Main Authors: Leclerc, Thomas, Vimal, Ruppert, Troispoux, Valérie, Périgon, Sophie, Scotti, Ivan
• Format: Journal Article
• Language: English
• Published: Springer Nature (since 2011)/EDP Science (until 2010) 2015
• Subjects: Environmental Sciences; Environmental studies; Geography; Global Changes; Humanities and Social Sciences; Guiana shield; Regeneration; Parentage analysis; Demogenetics; Amazon; Spatial genetic structure; Bayesian clustering; Tropical rainforest
• ISSN: 1286-4560; 1297-966X
• DOI: 10.1007/s13595-015-0462-0

Key message Forest disturbance affects the within-population distribution of genetic diversity, but not its overall levels, in a tropical pioneer tree species. In particular , clumps of related saplings with impoverished diversity are found in canopy gaps but not under forest cover. Context Forest disturbances can have long-term consequences on the genetic structure of tree populations, because they can alter the demographic properties of the regeneration process and favour some subpopulations/genotypes, both by stochastic processes and by selection. Intermediate disturbances tend to favour species diversity, at least in highly diverse communities , but their effect on intra-specific diversity is unknown. Aims In this study, we have looked at the genetic consequences of forest disturbance in a stand of the long-lived Neo-tropical pioneer species, Jacaranda copaia. Methods The study site was experimentally logged in 1984, and the canopy gaps generated by the logging were mapped. Seedlings of J. copaia colonised the gaps, as expected, at a higher density than in the surrounding forest. In 2006, we exhaustively sampled all saplings and adult trees available in a 25-ha area. The samples were genotyped at nine microsatel-lite loci, and the distribution of genetic diversity was inspected by analyses of spatial autocorrelation, automated Bayesian assignment and comparisons of diversity between cohorts by bootstrap (RaBoT). Results Spatial autocorrelation was found to extend farther in post-disturbance saplings than in the undisturbed population (100 m and beyond versus less than 50 m), and divergent clumps (F ST =0.05) of related genotypes were found; genetic Handling Editor: Ricardo Alia Contribution of the co-authors TL analysed data; RV collected samples and data, ran data analyses and wrote the paper; VT and SG collected and cured data; IS conceived the experiment, ran data analyses and wrote the manuscript. Thomas Leclerc tragically deceased in a car accident during his internship in French Guiana while carrying out this research. The remaining authors completed the study and wrote the manuscript on his behalf. This paper is dedicated to his memory and to his family and friends. Electronic supplementary material The online version of this article (diversity was found to be impoverished in each clump relative to the global population at about half of the loci. Conclusion Overall, our results suggest that forest disturbance has changed the patterns of distribution of genetic diversity , with potential consequences on long-term population viability.