Icelandic Forest Research

Reykjavík, Iceland

Icelandic Forest Research

Reykjavík, Iceland
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Nechita C.,National Institute for Research and Development in Forestry Marin Dracea | Nechita C.,Stefan Cel Mare University of Suceava | Popa I.,National Institute for Research and Development in Forestry Marin Dracea | Eggertsson O.,Icelandic Forest Research
Science of the Total Environment | Year: 2017

Tree-ring information and climate response data were applied to investigate the potential of the Carpathian Mountains to influence tree-growth patterns. Recent studies reveal the importance of constructing a dense spatial network of oak tree-ring chronologies in this area, which may be the key to linking the North Central European and East Mediterranean tree records. We establish sixteen oak (Quercus robur L.) and sessile oak (Quercus petraea (Matt.) Liebl.) site chronologies along a longitudinal gradient (from 22.47 to 26.58 E) in Northern Romania in an attempt to elucidate the impact of climate on oak growth. Even with differences generated by interspecific features, habitats and climatic regimes, a common macroclimatic marker for the NW and NE sites was established by comparing two groups of chronologies separated by the Carpathian chain. We found that precipitation in April (P4) and June (P6) were the primary climate factors that affected tree growth in the NW region. For the NE region, the temperature in January (T1) and March (T3) and precipitation in May (P5) were revealed to be the major limiting climatic factors. The spatial variability of the correlation coefficients indicates a decreasing trend in correlation intensity with precipitation from NW to NE, particularly during the current growing season (March–July). Oak trees from the NW and NE regions have adapted to different local climatic conditions and only respond uniformly to severe climate events (e.g., the 1904 drought). The higher occurrence of extreme years during the 20th century, particularly in the NE region, was in accordance with the rise of precipitation variability in the current growing season. The changes in the tree-growth pattern and climatic response of the chronologies of the studied sites in the NW and NE regions were linked to the local climates induced by the Carpathian Mountains. © 2017 Elsevier B.V.

Skulason B.,Copenhagen University | Skulason B.,Icelandic Forest Research | Hansen O.K.,Copenhagen University | Nielsen U.B.,Copenhagen University
Scandinavian Journal of Forest Research | Year: 2017

A field test with 26 provenances of subalpine fir and corkbark fir was established at three sites in Denmark and one site in Iceland in 1999. Survival, growth and Christmas tree quality were assessed after 10 growing seasons in Denmark and 12 in Iceland. Provenances showed significant differences for all measured traits. The western-most subalpine fir provenances from Washington state and British Columbia showed the overall best results in Denmark with the highest survival (after 15 years), fastest growth in height and highest Christmas tree quality and profitability as well as both good postharvest needle retention and high resistance to pests. The corkbark fir provenances also showed high Christmas tree quality and the lowest frequency of fork formation, but corkbark fir provenances also exhibited the poorest postharvest needle retention. In Iceland, the corkbark fir provenances generally showed the highest survival rate and Christmas tree quality. The White River provenance from British Columbia is recommended for use in Denmark. The Mount Taylor provenance from the Cibola National Forest in New Mexico is recommended for use in Iceland. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Piermattei A.,University of Cambridge | Piermattei A.,Swiss Federal Institute of forest | Piermattei A.,Marche Polytechnic University | Urbinati C.,Marche Polytechnic University | And 10 more authors.
Global and Planetary Change | Year: 2017

Seasonally formed, perennial growth increments of various organisms may possibly contain information about past environmental changes, well before instrumental measurements occurred. Such annually resolved proxy records have been mainly obtained from terrestrial archives, with a paucity of similar data originating from marine habitats. Iceland represents ideal conditions to develop both, tree ring (dendro) and bivalve shell (sclero) chronologies from adjacent sites. Here we introduce the first network of Icelandic birch (Betula pubescens Ehrh.) and rowan (Sorbus aucuparia) dendrochronologies, as well as ocean quahog (Arctica islandica L.) sclerochronologies. In order to identify the dominant external drivers of tree and shell growth, we assess the common growth trends and growth extremes within and between the terrestrial and marine records, as well as relationships of both archives with instrumental-based meteorological indices. Capturing a strong signal of June–August mean air temperature, the dendrochronologies are significantly positively correlated to each other. The sclerochronologies, however, reveal much lower growth coherency, which likely results from different sampling strategies and growth habitats. Disagreement between the dendro- and sclerochronologies possibly originates from unequal sample size, offset in the seasonal timing and rate of the growth, as well as varying sensitivities to different environmental factors. Our results emphasize the importance of considering a wide range of species and taxa to reconstruct a more complete picture of terrestrial and marine ecosystem functioning and productivity across various spatiotemporal scales. © 2017 Elsevier B.V.

Karlsdottir L.,University of Iceland | Hallsdottir M.,Icelandic Institute of Natural History | Eggertsson O.,Icelandic Forest Research | Thorsson Ae.T.,University of Iceland | Anamthawat-Jonsson K.,University of Iceland
Icelandic Agricultural Sciences | Year: 2014

Past episodes of birch hybridization in Iceland were studied by pollen analysis. The low stature and polycormic form of downy birch Betula pubescens in the subarctic probably results from such hybridization with the dwarf birch Betula nana. Two previous studies in different regions in Iceland revealed events of hybridization connected to early B. pubescens expansion. The present study examined a peat monolith from Thistilfjördur, North-east Iceland, covering the last ten thousand years. Betula pollen was measured, proportions of B. nana and B. pubescens calculated and the presence of hybrids estimated. Betula pubescens expansion started around 7.2 cal ka BP with a peak in non-triporate pollen, indicating hybrids. Low Betula pollen concentrations followed. A second period of considerable hybridization is indicated around 3.3 cal ka BP. Both peaks were associated with B. pubescens expansion.

Elefsen S.E.,Agricultural University of Iceland | Frey P.,French National Institute for Agricultural Research | Frey P.,University of Lorraine | Sverrisson H.,Icelandic Forest Research | Hallsson J.H.,Agricultural University of Iceland
European Journal of Plant Pathology | Year: 2014

The basidiomycete Melampsora larici-populina causes foliar rust on Populus species from the sections Aigeiros and Tacamahaca, causing reduction in biomass production and economic losses. In the present study, samples of Icelandic M. larici-populina were collected for analysis of genetic diversity and population structure. A total of 439 isolates, collected at 15 locations, and analysed using 22 microsatellite markers were compared to data from French M. larici-populina populations. Twenty-one of the loci analysed were polymorphic, with an average of 3.4 alleles per locus. The mean observed and expected heterozygosities for all populations were 0.35 and 0.38. Evidence was found for a substructure within the Icelandic population with three subpopulations being the most likely scenario with low levels of gene flow. The population structure seen here is most likely shaped by both isolation and genetic drift as well as repeated events of colonization. In the future it can therefore be expected that regional poplar rust genotypes in Iceland change by two different modes; on one hand by transport of spores within the country and on the other hand by repeated colonization events. The results reported here underline the importance of closely monitoring the development of fungal diseases in Iceland, and to carefully select for resistance in Icelandic plant breeding programs. © 2014 Koninklijke Nederlandse Planteziektenkundige Vereniging.

Sigurdsson B.D.,Agricultural University of Iceland | Medhurst J.L.,University of Tasmania | Wallin G.,Gothenburg University | Eggertsson O.,Icelandic Forest Research | Linder S.,Southern Swedish Forest Research Center
Tree Physiology | Year: 2013

The growth responses of mature Norway spruce (Picea abies (L.) Karst.) trees exposed to elevated [CO2] (CE; 670-700ppm) and long-term optimized nutrient availability or elevated air temperature (T E; ±3.9°C) were studied in situ in northern Sweden in two 3year field experiments using 12 whole-tree chambers in ca. 40-year-old forest. The first experiment (Exp. I) studied the interactions between CE and nutrient availability and the second (Exp. II) between CE and T E. It should be noted that only air temperature was elevated in Exp. II, while soil temperature was maintained close to ambient. In Exp. I, C E significantly increased the mean annual height increment, stem volume and biomass increment during the treatment period (25, 28, and 22%, respectively) when nutrients were supplied. There was, however, no significant positive CE effect found at the low natural nutrient availability. In Exp. II, which was conducted at the natural site fertility, neither C E nor TE significantly affected height or stem increment. It is concluded that the low nutrient availability (mainly nitrogen) in the boreal forests is likely to restrict their response to the continuous rise in [CO2] and/or TE. © 2013 The Author.

Zlatanov T.,Forest Research Institute Sofia | Schleppi P.,Swiss Federal Institute of forest | Velichkov I.,Forest Research Institute Sofia | Hinkov G.,Forest Research Institute Sofia | And 4 more authors.
Forest Ecology and Management | Year: 2013

Components of structural diversity of abandoned chestnut (Castanea sativa Mill.)-dominated and co-dominated forests along an altitudinal gradient in the Belasitsa mountain region of Southwest Bulgaria were evaluated, including: (i) tree species composition; (ii) differentiation in diameter, height and age; (iii) tree crown defoliation and light transmission; and (iv) regeneration composition and abundance. Competition between tree species and its influence on current stand structure were analysed. Lack of management had triggered rapid structural and successional development in formerly chestnut mono-dominated forests which have now been invaded by midseral and later seral vegetation dominated by European beech (Fagus sylvatica L.) and sessile oak (Quercus petraea Liebl.). Distribution of sample plots according to diameter differentiation for chestnut showed positive differentiation values (dominance of chestnut with respect to other species) in 43 of a total of 46 plots sampled. Structure is much more balanced in terms of height differentiation. In the absence of management, chestnut blight has been a major stress factor and is likely an important driver of chestnut decline. The proportion of chestnut trees infected by chestnut blight disease exceeded 80% in 28 plots. Nearly one third (31%) of all sampled trees were characterized by a degree of defoliation of more than 60%. Despite the low levels of light at the forest floor, the density of the regeneration stratum was relatively high (averaging 19,300ha-1). An important finding is the retained regeneration potential of chestnut (31% of all seedlings). Chestnut seedlings, however, appeared to be poorly adapted to shading and rapidly declined in density and growth while seedlings of most competitors survived longer and dominated the regeneration stratum. © 2012 Elsevier B.V.

Alberdi I.,Instituto Nacional Of Investigacion Y Tecnologia Agraria Y Alimentaria Inia | Alberdi I.,Polytechnic University of Mozambique | Michalak R.,UN Economic Commission for Europe | Fischer C.,Swiss Federal Institute of forest | And 17 more authors.
Forest Policy and Economics | Year: 2016

The supply of wood in Europe on a sustainable basis is highly relevant for forestry and related policies, particularly in relation to (i) analysing global change mitigation strategies and carbon accounting (ii) establishing realistic forecasts and targets for wood resources, biomass and renewable energy and (iii) assessing and supporting strategies for an increased use of wood.Therefore, it is relevant to have robust information of the availability for wood supply. The main aim of this paper is to harmonize the concept of 'forest available for wood supply' (FAWS) at European level.The data employed in this study was acquired through two questionnaires. The first questionnaire, conducted under the framework of COST Action FP1001 and a second questionnaire was completed by national correspondents and members of the UNECE/FAO.The analysis showed that reasons for the exclusion of forest from FAWS are diverse. Legal restrictions and specifically 'Protected areas' are considered by 79% of the countries while very few countries consider economic restrictions.A new FAWS reference definition is provided and the consequences of using this new definition in eight European countries were analysed. Application of the proposed definition will increase consistency and comparability of data on FAWS and will result in decreasing the area of FAWS at a European level. © 2016.

Oddsdottir E.S.,Icelandic Forest Research | Oddsdottir E.S.,University of Helsinki | Oddsdottir E.S.,University of Iceland | Eilenberg J.,Icelandic Forest Research | And 5 more authors.
Agricultural and Forest Entomology | Year: 2010

Weevil larvae of the genus Otiorhynchus are a serious problem in agriculture and forestry, causing damage to a wide range of plant species, primarily by larval feeding on roots. Otiorhynchus larvae are a serious pest in forest plantations in Iceland, causing 10-20% mortality of newly-planted seedlings. We studied the effects of soil fungi on the survival of Otiorhynchus sulcatus larvae. The larvae were introduced into pots with birch seedlings grown in: (i) nursery peat; (ii) nursery peat inoculated with three different species of ectomycorrhizal fungi; (iii) nursery peat inoculated with insect pathogenic fungi; (iv) nursery peat inoculated with ectomycorrhizal fungi and insect pathogenic fungi; and (v) nursery peat inoculated with natural forest soil from Icelandic birch woodland. Larval survival was negatively affected by inoculation of: (i) the ectomycorrhizal fungus Laccaria laccata; (ii) the ectomycorrhizal fungus Cenococcum geophylum; (iii) the insect pathogenic fungus Metarhizium anisopliae; and (iv) forest soil. Inoculation with the ectomycorrhizal fungus Phialophora finlandia did not have any significant effect on larval survival. No significant synergistic effect was found between insect pathogenic and ectomycorrhizal fungi. It is concluded that ectomycorrhizal and insect pathogenic fungi have a significant potential in biological control of Otiorhynchus larvae in afforestation areas in Iceland. Further studies are needed to establish the effect of these fungi in the field and to analyse how mycorrhizal fungi affect root-feeding larvae. © 2010 The Authors. Journal compilation © 2010 The Royal Entomological Society.

Oddsdottir E.S.,Icelandic Forest Research | Oddsdottir E.S.,University of Helsinki | Oddsdottir E.S.,University of Iceland | Eilenberg J.,Copenhagen University | And 4 more authors.
Applied Soil Ecology | Year: 2010

We present novel findings highlighting the early effects of inoculation of downy birch (Betula pubescens Ehrh.) seedlings with factorial combinations of beneficial soil fungi, namely, ectomycorrhizal and insect pathogenic fungi, on Otiorhynchus spp. larval root herbivory under Icelandic field conditions.Birch seedlings were pre-treated with (1) a mixture of four ectomycorrhizal fungal species: Paxillus involutus (Batsch: Fr.) Fr., Telephora terrestris Ehrh.: Fr., Phialophora finlandia Wang & Wilcox. and Hebeloma sp., (2) the insect pathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin or (3) a combined inoculum that included the four ectomycorrhizal fungal species and M. anisopliae. Non-inoculated seedlings served as untreated controls. Inoculated and control seedlings were transplanted into soils at three different sites representing eroded land, birch woodland and heathland.Assessment following the first growing season indicated that the effects on Otiorhynchus spp. larval root herbivory and seedling productivity of pre-inoculation with the ectomycorrhizal fungal species mixture and the insect pathogenic fungus, M. anisopliae, were highly dependent on site and treatment. Inoculation with ectomycorrhizal fungi and M. anisopliae significantly reduced root herbivory in both the birch woodland and, in particular, the eroded land sites. In the heathland site, no or even negative effects on root herbivory were observed. However, potential synergistic effects of combined inoculation with both ectomycorrhizal fungi and M. anisopliae were not identified under these experimental conditions.Accumulated seedling mortality ascribed to root herbivory after three growing seasons showed a significant site dependent response, but no significant treatment effect was detected.The effects of ectomycorrhizal and insect pathogenic fungi on root herbivory are discussed and we conclude that significant, although mostly unidentified, interactions between the inoculated fungi and the naturally occurring soil microorganisms may explain these findings. Such interactions require further detailed investigation in order to develop an efficient strategy for soil inoculation with beneficial fungi. © 2010 Elsevier B.V.

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