Format: ORAL

Enrique Hernndez-Rodrguez1,2(enrique.hernandezrodriguez@uqat.ca)*, Adriel M. Sierra2,3,4,5, Marta Alonso-Garca2,3,4,5, Juan Carlos Villarreal A. 2,3,4,5, and Nicole J Fenton1,2

1Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada. 2Centre d’étude de la forêt (CEF), Québec, QC, Canada. 3Département de Biologie, Université Laval, Québec, QC, Canada. 4Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC, Canada. 5Centre d’études nordiques (CEN), Université Laval, Québec, QC, Canada. *Contact: enrique.hernandezrodriguez@uqat.ca

Habitat loss is the primary driver of species diversity decline. One effect of habitat loss is changes in the occurrence of new land cover (composition) and the spatial pattern of different land cover (configuration) at different scales across the landscape. Although the effects of changes in landscape composition and configuration (LCC) on species richness are increasingly well understood, little is known about the response of genetic diversity to such changes, particularly in non-vascular plants such as mosses. In this study, we used a multiscale approach to assess the effects of changes in LCC on the population genetics of the dominant asexual reproduction moss Dicranum flagellare. We sampled and SNP-genotyped 191 stems of D. flagellare from 12 old-growth boreal forest fragments in eastern Quebec, Canada. Our results indicate that genetic diversity (e.g., nucleotide diversity and allelic frequency) of D. flagellare is primarily negatively influenced by old forest reduction at large landscape scales (8-9 km radii; landscape composition). In addition, patch density (landscape configuration) of young forest areas reduces the genetic diversity of D. flagellare from old forest at small scales (2 km radius). We also found evidence of spatial genetic structure between and within populations depending on the old forest percentages (<40 % and >40 %) in the landscape. Our study shows that habitat loss at large scales and aggregation of recent disturbance areas at small scales affect the genetic diversity and spatial structure of non-vascular plants. Because of habitat loss at large scales, our results are useful for establishing logging thresholds that promote species conservation in landscapes with logging plans.