Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
S. 26 i https://www.iufro.org/fileadmin/material/publications/proceedings-archive/20209-ctre-proceedings-19.pdf
Authors
Wiktoria Kaczmarek-Derda Anne-Kari Holm Lars Olav Brandsæter Knut Asbjørn Solhaug Inger Sundheim FløistadAbstract
No abstract has been registered
Abstract
S. 33 i . https://www.iufro.org/fileadmin/material/publications/proceedings-archive/20209-ctre-proceedings-19.pdf
2018
Abstract
No abstract has been registered
Authors
Jørn Henrik Sønstebø Mari Mette Tollefsrud Tor Myking Arne Steffenrem Anne Eskild Nilsen Øyvind Meland Edvardsen O. Ragnar Johnskås Yousry A. El-KassabyAbstract
Seed from orchards, established from breeding programs, often dominate the planting stock in economically important tree species, such as Norway spruce. The genetic diversity in seed orchards’ crops depends on effective population size which in turn is affected by many factors such as: number of parents in the orchard, seed orchards’ design, fecundity, and pollen contamination. Even though seed orchards’ seed is extensively used over large regions, very few studies have addressed how well their crops reflect the genetic diversity present in the regions where they are planted. Here we have investigated the genetic diversity (by means of 11 microsatellites) of two Norway spruce seed orchard populations with different number of parents (60 and 25) and compared this with seed crops collected in the semi natural forest and natural unmanaged populations. We found that the ratio between the effective population size (N e ) and actual number of parents (N) varied between 0.60 and 0.76 in the orchards’ seedlots. A reduction in genetic diversity (mainly allelic richness) was detected in a few seedlots, mainly where the number of parents was low. Our results also show that pollen contamination play an important role in maintaining the genetic diversity in orchards’ seedlots, particularly when the number of parents is low. The population genetic structure among seed orhcards and natural populations is shallow suggesting that re- generation with seed from current seed orchards will have limited effect on the overall genetic diversity.
Abstract
No abstract has been registered
Abstract
Throughout history, man has strongly utilized and affected forest genetic resources in Europe. From an evolu-tionary perspective deforestation/fragmentation (→genetic drift), transfer of seeds and plants to new environ-ments (→mainly gene flow) and selective logging (→selection) are most relevant and have been particularlyaddressed in this review. In contrast to most conifers, broadleaved tree populations have been especially reducedby historic fragmentation, and consequently, the related genetic effects have been possibly more pronounced.Widespread wind-pollinated species with wind/animal dispersed seeds appear to be more resilient to frag-mentation than species with e.g. small geographic ranges and gravity dispersed seeds. In addition, naturallyfragmented populations in the range margins may be more vulnerable than central populations as conditions forgene flow are generally impaired in peripheral areas. Traits important for adaptation (e.g. bud burst, bud set) arecontrolled by many genes, and as a corollary of fragmentation such genes are lost at a low rate. Large scalecommercial translocation of seeds and plants for forestry purposes applies mostly to conifers and dates backabout two centuries. Although many translocations have been successful in a forestry perspective, exposure tonew selective regimes has sometimes challenged the adaptive limits of populations and caused setbacks or evendiebacks of populations, as well as influencing neighbouring populations with maladapted genes (e.g. Scots pine,maritime pine, larch). Many tree species have substantial plasticity in fitness-related traits, which is vital forsurvival and viability following translocations. Selective logging has been practiced in Europe over the last twocenturies and implies removal of superior trees with respect to growth and quality. Such traits are partly undergenetic control. Consequent removal of superior trees may therefore have negative effects on the remaining genepool, but this effect will also be counteracted by extensive gene flow. Although humans have strongly affectedEuropean forest trees over the last millennia, we argue that they are still resilient from an evolutionary perspective.
Abstract
The Baltic region includes in this report Fennoscandia (Norway, Sweden, Finland, Denmark), the Baltic states (Estonia, Latvia, Lithuania) and Poland. This region is fairly heterogeneous as regards forest history, forest policy, forest economy as well as climate and conditions for forest growth. The climate of the Baltic region is cool, but still drastically modified by the Gulfstream which skirts the western coast of Scandinavia, giving rise to much warmer summers and milder winters than expected based on the latitude. The warming associated with climate change is expected to be particularly pronounced in winter and at high latitudes. In coastal areas precipitation may increase notably. With elevated temperature, the frequency of both spring frost and drought events is predicted to increase in continental parts. The vegetation and forest types are heterogeneous. Fennoscandia has a large proportion of boreal vegetation where coniferous forests dominate and many broadleaves common in Central Europe are rare and scattered. In the Baltic region the most distinct marginal populations are those at the northern fringe of their distribution. The distribution ranges are limited by a combination of different factors such as low winter temperatures, short growing season either for growth or for seed maturation, soil types and human influence. Fragmentation may limit gene flow between stands, and some populations also show slight inbreeding. The countries in the region have protected jointly 4,9 M ha in the main MCPFE categories. The northern part of the region seems to put more weight on nature conservation through no intervention whereas the southern part emphasizes conservation through active management. The countries of the Baltic region have uploaded altogether 1'172 in situ genetic conservation units in the European Information System on Forest Genetic Resources (EUFGIS).