Environment drives spatio-temporal patterns of clonality in white spruce (Picea glauca) in Alaska

• Main Authors: Wuerth, David Gabriel, Eusemann, Pascal, Trouillier, Mario, Burras, Allan, Burger, Andreas, Wilmking, Martin, Roland, Carl A., Juday, Glenn P., Schnittler, Martin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: alaska range; Brooks Range; Alaska
• Online Access: http://hdl.handle.net/1807/92504; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfr-2018-0234

Many plant species reproduce by cloning, if environmental conditions are unfavorable for sexual reproduction. To test the alternative hypotheses whether cloning is an â exit strategyâ or caused by selection, clonal growth in white spruce (Picea glauca (Moench) Voss) was investigated in three stands in Alaska, each consisting of a core (closed forest) and an edge (treeline) plot. A total of 2571 trees were mapped and genotyped with 11 SSR markers. The proportion of clonal trees follows a moisture gradient and was lowest in the dry Interior basin (4.5%), followed by the sites at the Alaska Range (9.0%) and Brooks Range (21.7%). At the two latter sites, clonal growth was more frequent in the edge plot. A comparison among 960 aged trees revealed that clonal growth becomes more likely with increasing age and continues over the life span of a tree. Genetic data do not indicate any genetic predisposition for cloning. Most likely, clonal growth in white spruce takes place via layering and depends on environmental conditions. Since performance of the trees, and therefore likely plant reproductive success, is lower in plots with a high proportion of clones, selection for clonal growth seems to be highly unlikely. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.