Ex situ conservation of forest genetic resources in Finland : Evaluation and adaptation of the current strategy

The objectives and methods of conservation of forest genetic resources in Finland are defined in the National Genetic Resources Program for Agriculture, Forestry and Fishery. While dynamic in situ conservation is the preferred type of conservation for most of the economically important tree species, Finland also manages and maintains genetic resources for nine tree species in ex situ conservation units. This document is a revision of the current national ex situ strategy and tries to unravel knowledge and conservation gaps, shows where conservation progress has been made to reach the defined conservation goals, and gives recommendations for the creation of a new action plan. The revision of the current ex situ framework also considers the global context of international treaties, conventions, and strategies aiming at improving genetic conservation in forest trees and monitoring conservation efforts more thoroughly. Due to its versatile applicability, ex situ genetic conservation has the potential to serve conservation needs in a multifunctional way and can make a significant contribution for short-term and long-term protection of forest genetic resources in response to abiotic and biotic threats. Ex situ conservation progress has been made for the highly endangered white elm population in Finland (Ulmus laevis) for which a significant part has been conserved in dynamic and static clonal archives covering the entire natural distribution range in Finland. Conservation progress has also been made for some other noble hardwood species: Oak (Quercus robur), Norway maple (Acer platanoides), and rowan (Sorbus aucuparia). Conservation gaps, on the other hand, do exist for whych elm (Ulmus glabra), linden (Tilia cordata), and in European ash (Fraxinus excelsior). This is mainly because of current biotic threats, which have the potential to drastically reduce the population sizes in these species. In the short-term (3–5 years from now) we recommend conservation plans for European ash, white elm, and whych elm that include the following actions: • Inventory and rescue of resilient European ash clones/families from the 4 existing archives into one dynamic conservation unit. • Development of static ex situ conservation methods (e.g., cryopreservation, seedlots) in European ash for fast rescue into long-term ex situ repositories. • Identification of new conservation units for white elm and wych elm with more favorable site conditions to replace the currently existing units in Paimio. • Achieving a conservation goal in white elm and wych elm of 270 and 425 unrelated individuals, respectively. In the long-term (10–15 years from now) we recommend achieving the following conservation goals for species which are not under immediate threat: • Norway maple (Acer platanoides): 600 unrelated individuals • Linden (Tilia cordata): 1,200 unrelated individuals • Oak (Quercus robur): 400 unrelated individuals • Rowan (Sorbus aucuparia): 400 unrelated individuals • Juniper (Juniperus communis): 400 unrelated individuals • Bird cherry (Prunus padus): 400 unrelated individuals In addition, Luke strongly emphasizes to make use of already existing and novel data resources to improve the genetic monitoring and population genetic analyses of forest genetic resources. Such resources should encompass: • DNA markers & genetic simulation tools • Climate data • Biodiversity databases • Novel sensing technologies for monitoring A detailed implementation plan with budgetary considerations will be prepared by LUKE during 2024 to achieve the conservation targets.

2024