A transnational network of genetic conservation units for forest trees was recently documented in Europe aiming at the conservation of evolutionary processes and the adaptive potential of natural or ...man‐made tree populations. In this study, we quantified the vulnerability of individual conservation units and the whole network to climate change using climate favourability models and the estimated velocity of climate change. Compared to the overall climate niche of the analysed target species populations at the warm and dry end of the species niche are underrepresented in the network. However, by 2100, target species in 33–65 % of conservation units, mostly located in southern Europe, will be at the limit or outside the species' current climatic niche as demonstrated by favourabilities below required model sensitivities of 95%. The highest average decrease in favourabilities throughout the network can be expected for coniferous trees although they are mainly occurring within units in mountainous landscapes for which we estimated lower velocities of change. Generally, the species‐specific estimates of favourabilities showed only low correlations to the velocity of climate change in individual units, indicating that both vulnerability measures should be considered for climate risk analysis. The variation in favourabilities among target species within the same conservation units is expected to increase with climate change and will likely require a prioritization among co‐occurring species. The present results suggest that there is a strong need to intensify monitoring efforts and to develop additional conservation measures for populations in the most vulnerable units. Also, our results call for continued transnational actions for genetic conservation of European forest trees, including the establishment of dynamic conservation populations outside the current species distribution ranges within European assisted migration schemes.
► We review theoretical and practical aspects of genetic conservation in forest trees. ► We present pan-European requirements for genetic conservation units of forest trees. ► The requirements ...promote dynamic conservation of genetic diversity. ► The requirements are now used for managing tree populations in 36 countries.
This paper provides a review of theoretical and practical aspects related to genetic management of forest trees. The implementation of international commitments on forest genetic diversity has been slow and partly neglected. Conservation of forest genetic diversity is still riddled with problems, and complexities of national legal and administrative structures. Europe is an example of a complex region where the distribution ranges of tree species extend across large geographical areas with profound environmental differences, and include many countries. Conservation of forest genetic diversity in Europe has been hampered by a lack of common understanding on the management requirements for genetic conservation units of forest trees. The challenge resides in integrating scientific knowledge on conservation genetics into management of tree populations so that recommendations are feasible to implement across different countries. Here, we present pan-European minimum requirements for dynamic conservation units of forest genetic diversity. The units are natural or man-made tree populations which are managed for maintaining evolutionary processes and adaptive potential across generations. Each unit should have a designated status and a management plan, and one or more tree species recognized as target species for genetic conservation. The minimum sizes of the units are set at 500, 50 or 15 reproducing individuals depending on tree species and conservation objectives. Furthermore, silvicultural interventions should be allowed to enhance genetic processes, as needed, and field inventories carried out to monitor regeneration and the population size. These minimum requirements are now used by 36 countries to improve management of forest genetic diversity.
Genetic resources of forest trees are considered as a key factor for the persistence of forest ecosystems because the ability of tree species to survive under changing climate depends strongly on ...their intraspecific variation in climate response. Therefore, utilizing available genetic variation in climate response and planting alternative provenances suitable for future climatic conditions is considered as an important adaptation measure for forestry. On the other hand, the distribution of adaptive genetic diversity of many tree species is still unknown and the predicted shift of ecological zones and species’ distribution may threaten forest genetic resources that are important for adaptation. Here, we use Norway spruce in Austria as a case study to demonstrate the genetic variation in climate response and to analyse the existing network of genetic conservation units for its effectiveness to safeguard the hotspots of adaptive and neutral genetic diversity of this species. An analysis of the climate response of 480 provenances, clustered into 9 groups of climatically similar provenances, revealed high variation among provenance groups. The most productive and promising provenance clusters for future climates originate from three regions that today depict the warmest and driest areas of the natural spruce distribution in Austria. Gap analysis of the Austrian genetic conservation units in the EUFGIS Portal suggests adequate coverage of the genetic hotspots in southern parts of Austria, but not in eastern and northern Austria. Therefore conservation measures and sustainable utilization of the valuable genetic resources in these regions need to be expanded to cover their high adaptive genetic variation and local adaptation to a warmer climate. The study shows that current conservation efforts need to be evaluated for their effectiveness to protect genetic resources that are important for the survival of trees in a future climate.
We quantified seed flow distances from seed trees of Quercus robur L. into areas with no forest cover based on a population of 147 trees growing next to an open heath land hosting many young oak ...seedlings. We sampled seedlings along four transects (6–700 m from the source population), and revealed likely parentage of seedlings by microsatellite genotyping data. We found seedlings that fitted the source population at distances up to 700 m, which was the furthest distance from the source population at which seedlings were sampled. However, we estimated that approximately half of the sampled seedlings did not originate from the source population, but must have been recruited from more distant oak populations, growing at least 500 m away. We conclude that the genetic origin and composition of natural regeneration of Q. robur are likely to originate from trees distributed at the landscape level rather than merely trees in the vicinity of the regenerated area. Implications for genetic management are discussed. The quantitative results fit well with qualitative reports of birds transporting acorns several hundred metres away from seed parents.
The aim of the present study was to investigate the genetic variation in Danish populations of the endangered European crab apple (Malus sylvestris). Special emphasis was given to hybridization ...between the wild species and its cultivated relative Malus ×domestica. A total of 178 wild individuals from four Danish populations were studied along with a reference sample of 29 old cultivars. The genetic variation within and among samples was studied at ten microsatellite marker loci. Additionally, a morphological analysis was carried out to identify hybrids and test for correspondence between phenotypic and genotypic indices of hybridization. From application of ordination and a model-based cluster analysis to the molecular data, two clusters were identified consisting of wild and cultivated individuals, respectively. This indicates that pronounced admixture between the two species is not present. At the population level, a high correspondence was found between geographic isolation from M. ×domestica and genotypic and morphological indices of hybridization. As expected, isolated populations appeared less affected by hybridization than poorly isolated populations. Isolated “pure” M. sylvestris populations could thus be identified. However, morphological and molecular evidences of hybridization were found to be divergent at the individual level. This is suggestive of some historical introgression into the M. sylvestris gene pool and indicates that relying exclusively on either morphological or molecular characters as diagnostic markers in studies of hybridization between M. ×domestica and M. sylvestris might lead to fallible results. Combined application of genetic and morphological markers is therefore recommended.
Dynamic conservation of forest genetic resources (FGR) means maintaining the genetic diversity of trees within an evolutionary process and allowing generation turnover in the forest. We assessed the ...network of forests areas managed for the dynamic conservation of FGR (conservation units) across Europe (33 countries). On the basis of information available in the European Information System on FGR (EUFGIS Portal), species distribution maps, and environmental stratification of the continent, we developed ecogeographic indicators, a marginality index, and demographic indicators to assess and monitor forest conservation efforts. The pan-European network has 1967 conservation units, 2737 populations of target trees, and 86 species of target trees. We detected a poor coincidence between FGR conservation and other biodiversity conservation objectives within this network. We identified 2 complementary strategies: a species-oriented strategy in which national conservation networks are specifically designed for key target species and a site-oriented strategy in which multiple-target units include so-called secondary species conserved within a few sites. The network is highly unbalanced in terms of species representation, and 7 key target species are conserved in 60% of the conservation units. We performed specific gap analyses for 11 tree species, including assessment of ecogeographic, demographic, and genetic criteria. For each species, we identified gaps, particularly in the marginal parts of their distribution range, and found multiple redundant conservation units in other areas. The Mediterranean forests and to a lesser extent the boreal forests are underrepresented. Monitoring the conservation efficiency of each unit remains challenging; however, <2% of the conserved populations seem to be at risk of extinction. On the basis of our results, we recommend combining species-oriented and site-oriented strategies. La conservación dinámica de recursos genéticos forestales (RGF) implica mantener la diversidad genética en el contexto de un proceso evolutivo y permitir el recambio generacional en el bosque. Evaluamos la red de áreas forestales manejadas para la conservación dinámica de RGF (unidades de conservación) en Europa (33 países). Con base en la información disponible en el Sistema Europeo de Información sobre RGF (Portal EUFGIS), mapas de distribución de especies y la estratificación ambiental del continente, desarrollamos indicadores ecogeográficos, un índice de marginalidad e indicadores demográficos para evaluar y monitorear esfuerzos de conservación de bosques. La red pan-europea tiene 1967 unidades de conservación, 2737 poblaciones de árboles y 86 especies de árboles. Detectamos poca coincidencia entre la conservación de RGF y otros objetivos de conservación en la red. Identificamos 2 estrategias complementarias: una estrategia enfocada en especies en la que específicamente se diseñan redes nacionales de conservación enfocadas a especies clave y una estrategia enfocada en sitios en la que unidades múltiples incluyen las llamadas especies secundarias conservadas en unos cuantos sitios. La red está muy desequilibrada en términos de la representación de especies, y 7 especies clave son conservadas en 60% de las unidades de conservación. Realizamos análisis de vacíos específicos para 11 especies de árboles, incluyendo evaluación de criterios ecogeográficos, demográficos y genéticos. Para cada especie, identificamos vacíos, particularmente en las partes marginales de su rango de distribución, y encontramos múltiples unidades de conservación redundantes en otras áreas. Los bosques Mediterráneos y en menor extensión los bosques boreales están insuficientemente representados. El monitoreo de la eficiencia de conservación de cada unidad sigue siendo un reto; sin embargo, <2% de las poblaciones conservadas parece estar en riesgo de extinción. Con base en nuestros resultados, recomendamos combinar estrategias enfocadas en especies con estrategias enfocadas en sitios.
The taxonomy of Prunus subgenus Prunus is notoriously problematic and reliable discriminating characters for species and subspecies identification are missing. Principal Component Analysis (PCA) was ...performed on different morphological data sets and useful diagnostic characters for Prunus spinosa and P. domestica ssp. insititia were found. Many traditionally used morphological characters were found unreliable. The hypothesis of widespread hybridization between Prunus spinosa and P. domestica ssp. insititia in Denmark were examined using PCA and HYWIN. It was found that hybrids between the two taxa are rare in Denmark.
This paper provides a review of theoretical and practical aspects related to genetic management of forest trees. The implementation of international commitments on forest genetic diversity has been ...slow and partly neglected. Conservation of forest genetic diversity is still riddled with problems, and complexities of national legal and administrative structures. Europe is an example of a complex region where the dis- tribution ranges of tree species extend across large geographical areas with profound environmental dif- ferences, and include many countries. Conservation of forest genetic diversity in Europe has been hampered by a lack of common understanding on the management requirements for genetic conserva- tion units of forest trees. The challenge resides in integrating scientific knowledge on conservation genet- ics into management of tree populations so that recommendations are feasible to implement across different countries. Here, we present pan-European minimum requirements for dynamic conservation units of forest genetic diversity. The units are natural or man-made tree populations which are managed for maintaining evolutionary processes and adaptive potential across generations. Each unit should have a designated status and a management plan, and one or more tree species recognized as target species for genetic conservation. The minimum sizes of the units are set at 500, 50 or 15 reproducing individuals depending on tree species and conservation objectives. Furthermore, silvicultural interventions should be allowed to enhance genetic processes, as needed, and field inventories carried out to monitor regen- eration and the population size. These minimum requirements are now used by 36 countries to improve management of forest genetic diversity.
PDF
