Genetic diversity of forest trees needs more attention

Experts on forest genetic resources (FGR) gathered at the EUFORGEN/FORGER workshop in Zagreb, Croatia on 25-27 March 2014 to discuss about inventories and databases on FGR in Europe. The experts belong to a network of National Focal Points that provides data to the European Information System on Forest Genetic Resources (EUFGIS), currently maintained as part of the European Forest Genetic Resources Programme (EUFORGEN).  The system currently provides the most complete information on the existing dynamic genetic conservation units designated for forest tree species across Europe. The experts were trained on the new features of EUFGIS, such as the integrated search function linked to the Geo-referenced Database on Genetic Diversity (GD2). Furthermore, they proposed potential improvements that could be applied to EUFGIS.

Four experts were interviewed on the topic of management of forest genetic resources in Europe. Below, Paraskevi (Evi) Alizoti, (Ass. Professor, Aristotle University of Thessaloniki, Faculty of Forestry and Natural Environment, Greece), Davorin Kajba (Professor, Department of Forest Genetics, Dendrology and Botany - Faculty of Forestry, University of Zagreb Croatia); Leena Yrjänä (Forestry Engineer, Metla - Finnish Forest Research Institute) and Eduardo Notivol (Senior Researcher, Forest Resources Unit, Agricultural Research and Technology Center (C.I.T.A.), Government of Aragon, Spain) answer our questions.

What are the major challenges that the European forests are facing today?

Evi: Climate change is affecting forest ecosystems across the whole Europe but mainly in its southern part that is considered a biodiversity hotspot due to the endemism and the high variation of flora and fauna. At this point we are lagging behind in knowledge on how to address this overarching threat for FGR. We are implementing conservation efforts across Europe, but most of the genetic conservation units of forest trees established up to now were designated according to the criteria of each particular country that in almost all cases did not include climate change. We need to focus on gaining knowledge from basic and applied scientific research on the impacts of climate change, as well as on formulating effective sustainable management practices, so that countries across Europe could follow those practices in the future while implementing FGR conservation in forest management.

Davorin: In Croatia, forests cover 47% of the country and are an important natural resource. About 95% of the forests regenerate naturally or semi-naturally, but we still have trouble obtaining sufficient quantities of seed for artificial regeneration. For pedunculate oak regeneration we need 1000 tonnes of acorns annually. We cannot find these quantities, as mast seed crop takes place only every 4-5 years in oaks. Other challenges in seed production are climate change and habitat loss.

How do you identify and conserve marginal tree populations?

Evi: Marginal populations could be identified at the leading and retreating edges of the distribution of forest tree species, as well as in high altitudes and ecologically marginal for each particular species niches. In the case of marginal tree populations threatened by severe heat waves or dry spells, we can monitor mortality and regeneration of reproductively mature trees. These two parameters could be the first criteria to judge on the plasticity of the specific populations on the imposed pressures and on their long-term viability. In case of severe mortality, leading to dramatic reduction of trees or lack of regeneration, we should take immediate measures, such as storage of seeds or cuttings in gene banks, or evacuation procedure or establishing conservation seed orchards in more favorable sites. All the above should be followed by close monitoring of the populations in situ to evaluate   their adaptive and evolutionary potential in the long term.

Are there many threatened tree populations in Europe?

Evi: We know that there are many forest tree populations currently suffering from dieback due to xerothermic conditions, as for example southern populations of Mediterranean firs. However, the individuals that can survive and successfully reproduce are better equipped to face the new climatic conditions and thus could promote the evolutionary adaptation of the species. We need time to study if and how tree populations can further evolve and if natural regeneration is sufficient to maintain viable populations.

Are national forest conservation strategies taking into account genetic resources in addressing climate change issues?

Eduardo: Not enough at the moment, but I’m quite optimistic for the future. In some countries, 20 or even 10 years ago forest genetic resources were completely neglected, while today they are more part of the day-to-day forest management. Now that we have documented the network of dynamic conservation units into EUFGIS, we should keep monitoring them, in order to guide their management in the future.

Leena: It may take a long time before scientific understanding feeds into practice. We are still quite behind with generating species-specific knowledge on the effects of climate change. For example, there are marginal populations of common ash in Finland but we do not know about their genetic diversity, which is often assumed to be low at the margin of the distribution. So in Finland we may not have enough genetic variation in ash populations to counteract the progressive expansion of ash dieback in Europe.

How are EUFORGEN and EUFGIS helping to address major challenges?

Leena: We have created a common language to speak about forest genetic resources. This is a great achievement and an important start for sharing knowledge.

Evi: The term ‘dynamic conservation unit’ was defined for the first time in the framework of the EUFGIS initiative. Furthermore, the EUFGIS Network agreed on the Pan-European minimum requirements that should be fulfilled when dynamic conservation units are being designated, so that the maintenance of the evolutionary processes within populations and their potential to adapt continuously to new challenges are secured. In addition, thanks to EUFORGEN, EUFGIS and FOREST EUROPE, genetic resources have now acquired more visibility among policymakers, while before the term ‘genetic’ was causing discomfort to non-experts on the subject.

Eduardo: The distribution maps created by EUFORGEN are useful for both policymakers and forest practitioners. The technical guidelines and monographs produced by EUFORGEN are useful materials for capacity development and dissemination.

Evi: EUFORGEN played a key role in capacity building. Students of higher education, researchers and forest practitioners are already using extensively the online resources on the EUFORGEN website. I think that developing additional learning materials, quiz questions or games related to the topic could additionally promote capacity building in primary and secondary education students.

Davorin: I use EUFORGEN technical guidelines to train students on how to develop in situ and ex situ conservation plans for particular species.

What are the most important next steps for this work?

Eduardo: Implementing a good monitoring system and collecting the right information will be a crucial step. But this is costly, so we will need resources.

Evi: We know much about the spatial patterns of genetic diversity of major forest tree species across Europe, but still we need more information to support decisions on which specific populations to conserve. We need to understand if the already designated conservation units harbor important genetic variation. Most of the research so far has focused on neutral genetic variation, but we urgently need to investigate more about adaptive genetic variation – genes that control adaptive traits in trees – to better understand the extent of the existing plasticity and adaptive potential of trees to changing climatic conditions. This piece of information is lacking for most of the tree species and could be crucial for success of sustainable forest management plans.

Do you have any other remarks?

Evi: One of the issues currently debated following the Nagoya Protocol is access and benefit sharing. Forest reproductive material is sometimes moved across borders without permission of the national authorities and there are several examples of commercial benefits not adequately shared. Governments are realizing that genetic resources are important not only from the biological, but also from the economic point of view. This issue is being discussed in the framework of an upcoming EU directive on the access and benefit sharing system among the European countries.

Davorin: Recent ice storms in the Balkans damaged large areas of forests and Slovenia, for example, will now need to import considerable amounts of forest reproductive material from abroad to reforest the damaged areas. A situation like this is a stimulus to establish more seed banks, especially for conifers, in order to prepare the forestry sector for an uncertain future.

A TV transmission including interviews with Davorin Kajba (EUFORGEN National Coordinator for Croatia), Jarkko Koskela (EUFORGEN Coordinator) and Czeslaw Koziol (EUFGIS Focal Point for Poland) was broadcasted as part of the TV show ‘Drustvene mreze’ (Translation: ‘Social networks’) on the Croatian National television (