H2020 GenTree Project: Optimizing the management and sustainable use of forest genetic resources in Europe

"GenTree's outreach products include a brochure, a newsletter, a Twitter feed (@GentreeProject), photos, blog posts and videos on the importance of genetic diversity in forest trees, all visible at: http://www.gentree-h2020.eu/ The project concluded with a series of international events held in Avignon, France, in January 2020 that highlighted the impressive scientific, technical and outreach work carried out by the GenTree consortium since 2016.

The major carbon-neutral scientific conference organized by GenTree this week (#rescueforest) was fully filmed, and the talks are available online via the project website. In total, 4,700+ trees from 12 species and 210 sites across Europe were sampled. Trees from the populations were characterized for traits useful for adaptation and response to global change, both from a conservation and breeding perspective, and their leaves were sampled for DNA extraction and functional trait measurements. The ecological and climatic conditions of the sites were described in detail. The DNA sequencing strategies used at GenTree target gene families and functions that are relevant to adaptation and that are similarly expressed across species, facilitating both sequencing and making cross-species comparisons relevant when looking at the demographic and selection processes involved in how diversity is expressed within and between populations, at the local, landscape, and regional levels. An important but rarely performed assessment of forest trees is to look for signs of selection in the early life stage, that of germination.

After a comprehensive assessment of seed performance across Europe, inspecting all project species, Pinus sylvestris, Betula pendula, and Pinus pinaster were chosen for the in situ germination experiment. The results showed high phenotypic variability in root emergence and stem development across distribution ranges and suggested an early adaptive response to the environment. Important traits and genetic combinations for breeding under climate change constraints were found in marginal and peripheral populations, which are in turn less resilient than main populations, making them urgent targets for both conservation and breeding. High-throughput methods such as drones and infrared spectral imaging, as well as leaf chemistry and genomics, were considered relevant in situ. Forest breeding material currently used in Europe showed a general, albeit truncated, similarity to wild material, which needs to be compensated for by creating ex situ core collections. Modeling occupied a large part of GenTree's activities.

It was used to improve and implement innovative, low-cost breeding strategies designed to balance genetic gain with loss of genetic diversity. Modeling also showed that genetic variability reduces the risk of population extinction under current and future climate conditions, particularly at the warm southern margins of the species' ranges. Thinning and assisted migration had a significant but low positive effect on vulnerability mitigation. Stakeholder engagement also occupied a significant part of the project activity. Stakeholders surveyed by GenTree were aware of the importance of genetic diversity for forestry. However, their perception of which policies or legislation are helpful or detrimental to FGR varied widely, mainly by country. To further increase awareness of how genetic diversity can be a nature-based solution for forest and forestry adaptation, GenTree organized several events targeting policymakers, forest managers, and administration executives, often in collaboration with the EUFORGEN program.