Germination and seed traits in common alder ( Alnus spp.): the potential contribution of rear‐edge populations to ecological restoration success

Inês Gomes Marques (1) , Carla Faria (1) , Sofia Isabel Rodrigues Conceição (2) , Roland Jansson (3) , Tamara Corcobado (4) , Slobodan Milanović (5) , Yann Laurent (6) , Ivan I. Bernez (7) , Simon Dufour (8) , Bohumil Mandák (9) , Hassan Ennouni (10) , Abdelouahab Sahli (10) , Mohammed Ater (10) , Francisco Javier Dorado (11) , Ana Delaunay Caperta (2) , Teresa Soares David , Alejandro Solla , Patricia María Rodríguez‐gonzález

1 Université de Lisbonne
2 Instituto Superior de Agronomia, LEAF, Linking Landscape, Environment, Agriculture and Food
3 Umeå University
4 BFW - Austrian Research and Training Centre for Forests, Natural Hazards and Landscape
5 MENDELU - Mendel University in Brno
6 AGROCAMPUS OUEST
7 ESE - Écologie et santé des écosystèmes
8 LETG - Rennes - Littoral, Environnement, Télédétection, Géomatique
9 IB / CAS - Institute of Botany of the Czech Academy of Sciences
10 UAE - Abdelmalek Essaadi University [Tétouan] = Université Abdelmalek Essaadi [Tétouan]
11 UEX - Universidad de Extremadura - University of Extremadura

The degradation of riparian ecosystems occurring throughout the past decades has motivated efforts aimed at the restoration of these ecosystems. The success of active revegetation approaches to restoration requires appropriate selection of reproductive material, which in turn requires knowledge of seed traits and germination. Alnus glutinosa (L.) Gaertn. (common alder) is a key riparian tree widely used in restoration projects, and has recently been classified as comprising three species: A. glutinosa; A. lusitanica Vit, Douda, & Mandak; and A. rohlenae Vit, Douda, & Mandak. To help guide restoration species selection, we assessed differences among populations of these species by (1) investigating seed weight, morphology, and germination success from a large population set and (2) modeling germination success in each species in relation to morphological traits and environmental conditions. Seeds were collected from 12 populations encompassing the latitudinal extremes of the species complex, and were then characterized and germinated. Ploidy levels and species were distinguished using cytometric analysis. Site-level climatic data and seed morphology data were used to model germination success for each species. All seed traits differed between populations and one morphological-trait (seed weight-to-area ratio) differed significantly between the three species. Germination modeling showed that the southwestern species, A. lusitanica, responded positively to high temperature extremes, suggesting tolerance to the climate changes projected for southern Europe. Populations of A. lusitanica located at the latitudinal rear edge of common alder's distribution appear to show establishment-facilitating adaptations, and therefore may contribute to ecological restoration efforts under a range of environmental conditions.

Mots clés: Alnus glutinosa; Alnus lusitanica; environmental cline; interspecific variation; ploidy; riparian forests

Domaines: Sciences du Vivant [q-bio]; Biodiversité et Ecologie; Ingénierie de l'environnement

Inês Gomes Marques, Carla Faria, Sofia Isabel Rodrigues Conceição, Roland Jansson, Tamara Corcobado, et al.. Germination and seed traits in common alder ( Alnus spp.): the potential contribution of rear‐edge populations to ecological restoration success. Restoration Ecology, 2021, 30 (3), pp.e13517. ⟨10.1111/rec.13517⟩. ⟨hal-03346418⟩