The LIFE + ELM project “Elms Alive” for the restoration of Ulmus minor and Ulmus laevis in Spain

Abstract

The degradation of European elm stands due to the negative impact of humaninduced changes in riparian ecosystems and the emergence of the highly aggressive Dutch elm disease (DED) pathogens prompted several elm breeding programs. In Spain, seven Ulmus minor clones tolerant to DED were recently selected and the small and fragmented Ulmus laevis populations were proven to be native. With this background, the LIFE+ ELM project (2014-2019; slogan “elms alive”; www.olmosvivos.es) has the overall objectives of monitoring acclimation of selected clones to riparian habitats presumed to be suitable for reintroduction (within the Tagus river basin), and to gain experience and ecological knowledge for future implementation of large scale elm restoration activities. It also intends to recover the use of elms as an ornamental shade tree in urban landscaping. By now, 11,156 individuals have been planted in forest and urban green areas, representing 67% of the total planned plantations. Plant material consists of clonal copies of the seven Ulmus minor clones obtained by micropropagation and U. laevis seedlings from two relict populations in the restoration area. The limited attractiveness of this last species for the elm bark beetles points to a low risk of DED damage in U. laevis. Due to the lack of earlier restoration attempts, it will be necessary to evaluate factors such as distance to the river, elevation, soil humidity, and incidence of pests, diseases and herbivory to form conclusions about the adaptability and survival of each elm genotype and species. To this end, experimental plots have been established in the restoration areas and preliminary results show a significant genotype x environment interaction. The ultimate goal is for the populations of both elm species to reach sexual maturity so they can contribute to gene flow and conservation of native genetic resources. Another key aim of LIFE + ELM is to transfer the knowledge and experience gained in the project to other players in forest restoration and the general public.