Tor Myking

Head of Department/Head of Research

(+47) 404 61 745
tor.myking@nibio.no

Place
Bergen - Fana

Visiting address
Fanaflaten 4, 5244 Fana

To document

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.

To document

Abstract

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

In Norway the common ash (Fraxinus excelsior L.) has its northernmost distribution in Europe. It grows along the coastal range as small fragmented populations. The first occurrence of ash dieback caused by Hymenoscyphus fraxineus in Norway was reported in 2008. At that time, the disease had already spread through large areas of southern and south-eastern parts of Norway. Since then the disease continued spreading with a speed of about 50- 60 km per year along the western coastal range. To monitor the disease development over time, we established eight permanent monitoring plots in south-eastern and western Norway in 2009 and 2012, respectively. In all plots tree mortality was high, especially among the youngest trees in south-eastern Norway. The extent of crown damage has continually increased in all diameter classes for both regions. In 2009, 76.8 % of all trees on the five monitoring plots in south-eastern Norway were considered to be healthy or slightly damaged, and only 8.9 % to be severely damaged. In 2015, 51.7 % were dead, 13.5 % severely damaged and only 25.7 % remained healthy or slightly damaged. To assess the infection pressure and spore dispersal patterns of the pathogen, we used a Burkard volumetric spore sampler placed in an infested ash stand in southern Norway. We examined the airborne ascospores of H. fraxineus and H. albidus captured on the sampling tape microscopically and with real-time PCR assays specific to these fungi. We detected very few ascospores of H. albidus, whereas ascospores of H. fraxineus dominated throughout entire sampling periods of 2009, 2010 and 2011. Spore discharge occurred mainly between the hours of 5 and 8 a.m., though the distinctive sporulation had yearly variation between 5-7 a.m. We observed the same diurnal pattern throughout the entire sampling period, with a seasonal peak in spore liberation between mid-July and midAugust, after which the number of ascospores decreased substantially. Similar diurnal patterns were observed throughout the sampling period except that after mid-August the number of trapped ascospores substantially decreased. To compare the genetic pattern of common ash in the northern and central ranges of Europe we analyzed the Norwegian samples together with available samples from central Europe by using chloroplast and nuclear microsatellite markers. We found that the northern range of common ash was colonized via a single migration route that originated in eastern or south-eastern Europe with little influence originating from other southern or western European refugia. In the northern range margins, genetic diversity decreased and population differentiation increased, coherent with a post-glacial colonization history characterized by founder events and population fluctuations. Based on our findings we discuss the future management and conservational implications.

To document

Abstract

The world’s need for industrial wood is expected to greatly increase in coming decades. Somatic embryogenesis (SE) is a way in which an almost unlimited number of genetically identical plants (clones) can be produced from a single mother plant/seed, and it offers an effective way to convey the genetic gain obtained in breeding to the planting stock. As cultures or methods of SE, for example in Norway spruce (Picea abies), may become the subject of intellectual property rights (IPRs), a legal conflict may arise between the right holder and the rights of the general public covered by the Every man’s rights to freely sample, for example, forest genetic resources (FGRs). Various IPR systems may be relevant for the protection of SE material in forestry, but they possibly differ in how well sufficient genetic variation can be encompassed by protection claims. We therefore specifically advocate awareness of genetic variation in future SE-related IPR claims in forestry, and argue that process patents are most applicable. In face of the bioeconomy, it is mandatory to be aware of the possible conflicts between IPRs and rights of the public to FGRs, and the genetic variation of future IPR-protected SE material in forestry.

To document

Abstract

During post glacial colonization, loss of genetic diversity due to leading edge effects may be attenuated in forest trees because of their prolonged juvenile phase, allowing many migrants to reach the colonizing front before populations become reproductive. The northern range margins of temperate tree taxa in Europe are particularly suitable to study the genetic processes that follow colonization because they have been little affected by northern refugia. Here we examined how post glacial range dynamics have shaped the genetic structure of common ash (Fraxinus excelsior L.) in its northern range compared to its central range in Europe. We used four chloroplast and six nuclear microsatellites to screen 42 populations (1099 trees), half of which corresponded to newly sampled populations in the northern range and half of which represented reference populations from the central range obtained from previously studies. We found that northern range populations of common ash have the same chloroplast haplotypes as south-eastern European populations, suggesting that colonization of the northern range took place along a single migration route, a result confirmed by the structure at the nuclear microsatellites. Along this route, diversity strongly decreased only in the northern range, concomitantly with increasing population differentiation and complex population substructures, a pattern consistent with a leading edge colonization model. Our study highlights that while diversity is maintained in the central range of common ash due to broad colonizing fronts and high levels of gene flow, it profoundly decreases in the northern range, where colonization was unidirectional and probably involved repeated founder events and population fluctuations. Currently, common ash is threatened by ash dieback, and our results on northern populations will be valuable for developing gene conservation strategies.

To document

Abstract

Rapporten gir en oversikt over granas (Picea abies) utbredelse, taksonomi og genetisk variasjon som en bakgrunn for å vurdere om planting av norske og utenlandske provenienser av gran kan ha ulike effekter på stedegent biologisk mangfold. Ifølge oppdraget skal en slik vurdering gis på bakgrunn av en sammenstilling av eksisterende kunnskap. Granas utbredelse i Europa er delt i et nordlig og et sørlig område som utgjør to klart adskilte genetiske grupper, sannsynligvis som følge av isolasjon gjennom flere istider. I nord danner gran et sammenhengende område som dekker nesten hele Fennoskandia, Estland, Latvia, Litauen, Hviterussland, nordre deler av Polen og den europeiske delen av Russland. I sør opptrer grana hovedsakelig langs fjellkjedene i sentrale og sørøstlige deler av Europa. I Norge er gran hovedsakelig utbredt i østlige og sentrale deler av landet, med spredte populasjoner i indre strøk av Vestlandet og i Øst-Finnmark. Både paleodata og genetiske data viser at grana vandret inn til Norge fra et stort Russisk istidsrefugium langs både nordlige og sørlige innvandringsveier. Samtidig tyder genetiske data på at grana også har overlevd siste istid i Skandinavia. Det finnes møtesoner i Skandinavia fra både et østlig og et vestlig refugium med genetiske subgrupper som følge av de ulike historiske prosessene. Videre bidrar genflyt over store avstander til genetisk homogenisering. Proveniens (fra latin «provenir» – komme fra, opprinnelse) henviser til områdene der et treslag vokser eller stedsopprinnelsen til frø eller trær, og er ikke et taksonomisk begrep. Ulike provenienser av gran fra flere europeiske land, særlig fra Tyskland og Østerrike, har blitt benyttet i flere tiår til skogplanting i Norge. Slike utenlandske provenienser kan skille seg i adaptive økologiske egenskaper som fenologi, hardførhet mot frost og kulde, evne til frøproduksjon og frøspredning, noe som igjen kan føre til ulik vekst- og spredningspotensiale. Granplanting påvirker det stedegne biologiske mangfoldet betydelig gjennom redusert lystilgang, endret vannbalanse og næringsomsetning i jorda. Man kunne således anta at de proveniensene av gran som har best vekstegenskaper ville påvirke den stedegne biodiversiteten mest. Imidlertid har søk i internasjonale databaser, så vel som forespørsler til miljø- og skogforskningsinstitusjoner i Europa, ikke avdekket noe litteratur eller erfaringsbasert kunnskap som bekrefter dette. Forskning på temaet er trolig ikke-eksisterende. Selv om ulike provenienser av gran skulle påvirke stedegent biologisk mangfold ulikt, vil slike forskjeller høyst sannsynlig være marginale, sammenlignet med effektene av selve granplantingen, der plantetetthet, skjøtsel av plantefeltene, endret jordkjemi og lysforhold er det viktigste påvirkningsfaktorene på biologisk mangfold. Norway spruce, provenance, afforestation, forestry, taxonomy, genetic variation, paleobotany, biodiversity, ecological traits, risk assessment, gran, proveniens, skogplanting, skogbruk, taksonomi, genetisk variasjon, paleobotanikk, biodiversitet, økologiske egenskaper, sårbarhetsanalyse

To document

Abstract

Sallow (Salix caprea L.) and rowan (Sorbus aucuparia L.) constitute small proportions of the deciduous tree volume in Scandinavia, but are highly preferred winter forage for moose and red deer, which occur at historically high densities. Thus, a possible decline of these tree species has been indicated. Against this background, we have reviewed the life histories of relevance for browsing, as well as the basic biology and genetics of sallow and rowan. The species show similarities with respect to short lifespan, small size and sympodial growth pattern, which are risk factors in a browsing context. They also have high juvenile growth rate, important for growing quickly out of reach of browsers. Sallow depends strongly on disturbance for establishment and is more demanding with respect to soil and light conditions than rowan, possibly important for the substantially lower abundance of sallow on the Norwegian Forest Inventory plots. Similarly, the relative recruitment of small size classes of sallow is less than for rowan. Although recruitment is reported to be hampered in wintering areas with high moose or red deer densities, the inventory data, however, dating only back to 1994, do not suggest a general decrease in any of the species. Sallow and rowan saplings show low mortality in moose and deer dominated areas and the species can be characterised as rather resilient to browsing. Of more concern is that browsing can constrain the development of mature rowan and sallow trees locally, with possible consequences for associated epiphytic biodiversity.

Abstract

Continued flexible exchange of forest genetic resources (FGR) in the Nordic region is important for sustainable forest management and for climate change adaptation and mitigation. For this reason, a high level political initiative identified a need to clarify the legal status of FGR in the Nordic region. The overall aim of this study was to assess whether it is necessary and possible to take legal steps to ensure that FGR remain available for conservation and sustainable use in and between the Nordic countries. A survey of the present situation revealed that although the Nordic countries have different domestic legislation on access to FGR, it has not caused any hinders for exchange. Thus, in effect the situation is quite similar in the Nordic countries. As for the future, it is unlikely that application of patent law and plant variety protection (UPOV) will restrict exchange of FGR, mainly due to the short protection periods of these regulations relative to the long generation time of main forestry tree species. For short rotation tree species, intellectual property rights (IPR) might prove to be more applicable. Concerning international agreements, it is premature to evaluate the effect of the Nagoya Protocol (2010) on access and benefit sharing for FGR, as well as recent FAO initiatives. Based on the current study, no legal steps or action seem necessary. To promote continuing simple exchange of FGR the Nordic countries are recommended to stay involved in those processes where relevant international agreements are debated and developed, facilitate simple procedures for exchange and establish a mechanism for surveillance of biotechnological methods that might increase the use of private property rights on FGR.

Abstract

CO2 Technology Centre Mongstad will be the world\"s largest test centre for testing and development of CO2 capture technology. The emissions to the atmosphere from CO2 Technology Centre Mongstad contain amines and may in addition contain or lead to the formation of degradation products from amine-based CO2 capture technology. An environmental baseline survey was conducted in 2011 prior to the operation. The survey performed is broad, and describes in detail the environmental situation both in terrestrial and aquatic ecosystems as well as relevant chemical compositions of a range of matrices such as soil, plants and water. The data collected in the monitoring program were used to propose a future monitoring program in the area.

To document

Abstract

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.

To document

Abstract

Aspen (Populus tremula L.) is associated with high biodiversity and provides high-quality forage for wild browsing herbivores in boreal and temperate ecosystems. The long-term persistence of aspen in many regions in Scandinavia has been questioned due to the historically high browsing levels. We here review the basic ecology, genetics and life histories of aspen in a browsing context. Browsers can suppress the regeneration of aspen and the relatively short lifespan of the trees result in frequent regeneration cycles and concurrent exposure to browsers. In the long term, browsing may reduce recruitment and delay maturation, increase mortality and ultimately cause a decline of aspen. Norwegian forest inventory data indicate a reduced recruitment rate of young aspen (diameter at breast height; 60–79 mm) during the last 25 years, but it is unclear whether this is all due to browsing. Regeneration may also be hampered by lack of disturbance. Recent genetic studies have shown that aspen may have substantial regeneration by seeds, which allows for effective migration. The main conclusion of this review is that although browsing may affect demography and local abundance of aspen, it is very unlikely to lead to the eradication of the species in Fennoscandia.

Abstract

Aspen (Populus tremula L.) is associated with high biodiversity and provides high-quality forage for wild browsing herbivores in boreal and temperate ecosystems. The long-term persistence of aspen in many regions in Scandinavia has been questioned due to the historically high browsing levels. We here review the basic ecology, genetics and life histories of aspen in a browsing context. Browsers can suppress the regeneration of aspen and the relatively short lifespan of the trees result in frequent regeneration cycles and concurrent exposure to browsers. In the long term, browsing may reduce recruitment and delay maturation, increase mortality and ultimately cause a decline of aspen. Norwegian forest inventory data indicate a reduced recruitment rate of young aspen (diameter at breast height; 60-79 mm) during the last 25 years, but it is unclear whether this is all due to browsing. Regeneration may also be hampered by lack of disturbance. Recent genetic studies have shown that aspen may have substantial regeneration by seeds, which allows for effective migration. The main conclusion of this review is that although browsing may affect demography and local abundance of aspen, it is very unlikely to lead to the eradication of the species in Fennoscandia.

Abstract

The northernmost range of beech (Fagus sylvatica L.) is in southern Norway and consists of two distinct and isolated distributions, a single population at Seim in West Norway and several adjacent populations in Vestfold, East Norway. The modest beech pollen deposits beyond these main distributions suggest that the Norwegian beech distribution has never been an extension of the south Scandinavian range. We used genetic markers and historical sources to trace the ancestor populations for the beech at Seim and Vestfold, hypothesising Denmark as the most likely source. Nuclear inter-simple sequence repeat markers, amplified by polymerase chain reaction (PCR), were applied to estimate genetic distances between beech populations in Norway, England and Denmark. The variation in chloroplast DNA polymorphism was estimated using PCR-restriction fragment length polymorphism. The nuclear genetic data indicate Denmark as a source for the beech in Norway, although the data are less certain in the case of Seim than in that of Vestfold. The populations from South England were genetically different from most Scandinavian populations. The genetic variation within Norwegian populations was only slightly lower than that of the English and Danish populations, questioning birds as vectors for dispersal. Thus, the pollen data and our results are in accordance with the intentional introduction and documented human migrations across Skagerrak before and during the Viking Age.

Abstract

Dormancy release as influenced by duration of outdoor winter chilling in Florence (Italy) was studied under different photoperiodic and temperature treatments in collected twigs of two European (Ulmus glabra Huds. and Ulmus minor Mill.) and four Asian (Ulmus pumila L., Ulmus parvifolia Jacq., Ulmus macrocarpa Hance and Ulmus villosa Brandis) elm clones. Photoperiod had no effect on dormancy release, and there was no evidence that photoperiod affected bud burst during quiescence in the studied elm clones. Thermal time (day degrees >0 °C) to bud burst decreased in all the clones with increasing outdoor chilling. Although all the clones exhibited a rather weak dormancy, they significantly differed from each other. Dormancy was released earlier in the Asian than in the European clones, and the clones could be ranked from the U. pumila clone (very weak and short dormancy) to the U. minor clone (relatively stronger and longer dormancy), the other clones being intermediate. In all the clones except U. minor, the observed decrement in thermal time to bud burst was efficiently explained as an inverse exponential function of the number of chill days ≤5 °C received outdoor in autumn and winter. Endodormancy, as measured by the single-node cuttings test, was weak and short in all the clones. The latter result suggests that correlative inhibitions were largely responsible for preventing bud burst during winter in these elm clones.

To document

Abstract

Dormancy release as influenced by duration of outdoor winter chilling in Florence (Italy) was studied under different photoperiodic and temperature treatments in collected twigs of two European (Ulmus glabra Huds. and Ulmus minor Mill.) and four Asian (Ulmus pumila L., Ulmus parvifolia Jacq., Ulmus macrocarpa Hance and Ulmus villosa Brandis) elm clones. Photoperiod had no effect on dormancy release, and there was no evidence that photoperiod affected bud burst during quiescence in the studied elm clones. Thermal time (day degrees >0 °C) to bud burst decreased in all the clones with increasing outdoor chilling. Although all the clones exhibited a rather weak dormancy, they significantly differed from each other. Dormancy was released earlier in the Asian than in the European clones, and the clones could be ranked from the U. pumila clone (very weak and short dormancy) to the U. minor clone (relatively stronger and longer dormancy), the other clones being intermediate. In all the clones except U. minor, the observed decrement in thermal time to bud burst was efficiently explained as an inverse exponential function of the number of chill days ≤5 °C received outdoor in autumn and winter. Endodormancy, as measured by the single-node cuttings test, was weak and short in all the clones. The latter result suggests that correlative inhibitions were largely responsible for preventing bud burst during winter in these elm clones.

Abstract

The Pasvik River valley is the easternmost part of Norway, and borders to Finland and Russia. In Norway it is known for its wilderness and taiga forests. During the 1960-1970s most of the mature pine forests were harvested, and large areas of pine stands have been naturally regenerated. In addition, large areas are covered with birch. The Pasvik River valley and the adjoining areas are therefore important both as an area for growing timber resources and for recreation. However, these areas have also been exposed to air pollution from Russian smelting industry since the 1930s. In addition to sulphur dioxide, emissions consist of various heavy metals which contaminate the surroundings. The main pollution source is the huge nickel plant in the Russian city Nikel, located only 10 km from the Norwegian border. For a long time there was general concern for the quality of the forest ecosystems in these areas. This concern accelerated in the mid-1980s.

Abstract

The Nordic region is characterized by simple, non-bureaucratic exchange of forest genetic resources (FGR) between countries that is strongly associated with the everyman\"s right legislation within the individual countries. The regime for international exchange of FGR is smooth and regarded as being very valuable for the forestry sector across the Nordic country borders as it secures the unrestricted availability of seeds and breeding material.

Abstract

There is great ecological, economic and social value within forest genetic resources – that is a fact. But so far, the true legal status of this resource has not been defined. This was the background for a meeting held in Vienna on 13 September 2010 which assembled forest and legal experts to discuss preliminary outputs from a NordGen project (2009-2010), initiated by representatives from Denmark, Finland, Norway and Sweden....

Abstract

The effect of air pollution from the Petchenganickel industrial complex, northwestern part of the Kola Peninsula, on forest vegetation was studied by combining three dormant monitoring networks in Finland, Russia and Norway, comprising a total of 21 plots that were revisited in 2004. Chemical composition of precipitation was monitored during 2004–2005, and indicated continuing high deposition of heavy metals and SO2 in the border area. The cover of epiphytic lichens on the trunks of downy birch (Betula pubescens) and Scots pine (Pinus sylvestris) was severely affected by pollution, and there was also a consistent negative effect on the abundance and richness of lichens and bryophytes on the forest floor in a more limited area. The effects of pollution on crown condition and stand growth were weak or absent. This study is an important reference for evaluating the effects of the planned renovation of the smelter in Nikel.

Abstract

An international EU/Interreg III Kolarctic project `Development and implementation of an environmental monitoring and assessment program in the joint Finnish, Norwegian and Russian border area`, was carried out during 2003–2006 as a joint undertaking between Norwegian, Finnish and Russian research institutes and environmental authorities. The aim of the terrestrial ecosystem sub-project of the Pasvik project was to develop and implement a monitoring and assessment programme for terrestrial ecosystems in the joint Finnish, Norwegian and Russian border area...

To document

Abstract

After two decades of monitoring forest health in Europe, in response to concern for negative effects of air pollution, a similar worry is now increasing in China. In a co-operative project between Chinese and Norwegian researchers a forest monitoring was implemented in the acid rain region in south China. During 2000–2004 two small watersheds were monitored: TieShanPing (TSP) near ChongQing City and LuChongGuan (LCG) near GuiYang City. They are covered by Masson pine (Pinus massoniana) forest. The methodology of the European intensive forest monitoring programme (ICP-Forests level-II) was adopted; including crown assessments, foliar chemistry, air and soil chemistry, and more. This paper presents results of this co-operative project. Considerable forest damage was revealed by monitoring the crown condition of Masson pine trees. The average defoliation percentage for all assessed trees (predominant, dominant and co-dominant pines, corresponding to Kraft classes 1–3) in the more acidified TSP was over 40% and remained stable throughout the monitoring period, accompanied by an extremely high mortality in some years. In contrast, the defoliation in the less acidified LCG was relatively low but increased considerably, from 16% to around 40%, within the 4 monitoring years. The significance of air pollution for the forest damage remains uncertain. The annual SO2 concentration in TSP and LCG is about 2 and 4 times higher than the critical level of 20 μg m−3 given in the LRTAP convention for effects on forests. Therefore the air pollution effects cannot be ruled out as contributing factors for forest damage. However, this cannot be substantiated based on the presented monitoring data since none of the specific symptoms of air pollution damage were observed. Furthermore, an analysis of the monitoring data did not reveal any significant correlation between defoliation and the soil chemical properties. It is noteworthy that the evident agents that were identified are capable of causing the observed forest damage. These agents were insect attacks and climatic stress. It is possible that the forest damage has complex causes.

Abstract

Results from a literature review on pinewood ecology, silviculture, genetics, aspects of history and forest resources of Scots pine (Pinus sylvestris L.) in western Norway are presented. The pinewoods cover 40 per cent of the forested land, 0.31 million ha. During the last 75 years, the area has increased by 17 per cent and the growing stock has risen from 10 to 34 million m3. The impact of man in previous times was very marked, and has had a significant influence on the present forest conditions. The pronounced climatic gradients mixed with the topographic variation - from the coastal plains via the fjord systems to the high mountains - is reflected in rather steep gradients in the pine forest vegetation. Various floristic elements can be distinguished, from oceanic via the suboceanic in the outer islands to the thermophytic, boreonemoral and boreal elements in the inner fjord districts and valleys. The introduction of spruce (Picea spp.) plantations on 10-15 per cent of former native pine forests has not negatively affected the bird fauna at the landscape scale. Although not particular species rich, the pine forests harbour species usually not found in other forest types. So far, most work in the field of silviculture and forest ecology in the pinewoods of West Norway has been in the form of case studies. Implications of the results for forestry in the region are briefly discussed.

Abstract

Based on field observations of leaf morphology and variation in chloroplast DNA (cpDNA) in Scandinavia, Norway has been suggested as a suture zone for elm (Ulmus glabra) from different glacial refugia. The aim of this paper was to study the geographical concordance between the maternally inherited cpDNA markers (16 populations) and the assumed polygenic and biparentally inherited leaf traits, studied in a field trial (five populations).Two cpDNA haplotypes were detected, but without geographical structure. Leaf traits showed a gradient from typical ssp. montana traits (relatively long, long tapering, absent acute lobes) in western populations to more ssp. glabra-like traits (relatively broad, short tapering, acute lobes present) in eastern and northern populations.The overall geographical concordance between haplotype distribution and leaf traits was limited, probably owing to different inheritance of cpDNA and leaf traits, but the spatial variation in leaf traits and cpDNA in a subset of common populations (n=5) was compatible with a dual migration of elm to Scandinavia. Both measures suggest a broad suture zone, covering the entire distribution of elm in Norway.The results are discussed in relation to the use of maternally inherited markers, such as cpDNA, in delimiting suture zones.

Abstract

Impact assessment for a proposed LNG plant has been carried out for three potential locations in northwest Russia. The impact from the plant is small, and the critical loads for terrestrial ecosystems and aquatic ecosystems will not be exceeded at any of the 3 locations.

Abstract

Genetic variation in adjacent Nordic populations of Acer platanoides L. and Betula pendula Roth was assessed by allozymes and in growth and phenology traits of juvenile trees grown in two field trials, and in growth chambers with free or restricted nutrient access. The objectives, based on the difference in the species' life-history traits, were to test the following hypotheses: 1. the population differentiation is higher in A. platanoides 2. the genetic variability 3. the phenotypic plasticity are larger in B. pendula. Analyses of variance revealed that, except for budburst, the growth and phenology traits generally supported the first hypothesis. The estimates of the coefficients of additive variance consistently disagreed with the second hypothesis. Allozyme data also supported the first hypothesis, but not the second. Finally, the phenotypic plasticity was larger in B. pendula.

Abstract

Sulphur deposition is high at all IMPACTS sites and exceed maximum levels observed in Europe and North-America. Dry deposition equals or exceeds wet deposition. The IMPACTS data, in particular those from the remote Lei Gong Shan site clearly document long-range transport of air pollutants. Due to the actual and future energy combustion and emission strategy in China, the long-range transport of air pollutants may significantly increase with subsequent increased environmental damage in rural and remote areas in China. In addition to sulphur deposition, depositions of reactive nitrogen (nitric acid and ammonia) and calcium are also important and clearly demonstrate that pH alone is not a good indicator for acid deposition. High concentrations of ground level ozone, above critical levels for vegetation and forest, are observed at the Liu Xi He site in Guangdong province. Soil acidification gives rise to high concentrations of toxic aluminium in soil water at several sites. At the Tie Shan Ping site in Chongqing aluminium occurs at a level where long-term harmful effects on trees might be expected. Defoliation and mortality have been severe, however, fairly stable. Insect attacks are apparently a major cause, but enhanced insect attacks might be an indirect effect of health weakening due to acidification. Defoliation has been considerable also in Liu Chong Guan in Guiyang, while the three other catchments had minor defoliation only. High foliar nitrogen concentrations are seen in Lei Gong Shan in Guizhou and Cai Jia Tang in Hunan, accompanied by low P/N-ratios. Statistical tests of vegetation change, so far only implemented in Liu Chong Guan, revealed minor changes in number and abundances of vascular plants, but a significant decline in number of bryophytes. This decline is probably related to climatic year-to-year variations. Data from other catchments and longer time periods are needed to identify vegetation changes related to soil acidification or direct effects of air pollutants. Modelling results from Tie Shan Ping suggest that the currently planned 20% reduction in sulphur emissions is far from sufficient to avoid further acidification. As more data are generated, dose-response relationships, critical load estimates and model predictions will obviously be improved.

Abstract

Additive variation in adaptive traits is a prerequisite for selection and adaptation to future environmental changes, but distribution of adaptive genetic variability between and within populations is poorly known in most forest trees. Owing to this deficiency, life history traits such as geographic range, pollination vector and seed dispersal capability, which significantly affect gene flow and thus the distribution of genetic variability, were used to evaluate the genetic resources in 23 Norwegian native forest tree species. Based on the combination of life history traits the species\" genetic resources were classified either as viable, potentially vulnerable or vulnerable, assuming a decrease in within-population variability in this sequence. Twelve widely distributed species with generally effective dispersal of pollen and seeds were considered viable (Pinus sylvestris, Picea abies, Juniperus communis, Betula pubescens, B. pendula, Alnus incana, A. glutinosa, Salix caprea, Populus tremula, Corylus avellana, Sorbus aucuparia, Prunus padus) and have as such no particular conservation needs. Effective seed dispersal of these species, as inferred from post-glacial migration rates, may be partly responsible for their generally early post-glacial appearance, and may, in combination with the wide ranges and relatively large evolutionary potential, indicate that viable species are best able to cope with climatic change. Among species with restricted ranges and more limited gene flow eight were considered potentially vulnerable (Quercus petraea, Q. robur, Fraxinus excelsior, Acer platanoides, Taxus baccata, Ilex aquifolium, Fagus sylvatica, Ulmus glabra) and three were considered vulnerable (Tilia cordata, Malus sylvestris, P. avium). Application of different intensities of a multiple population breeding system (MPBS) is considered the most appropriate mode of conserving genetic resources in these species.

Abstract

Winter dormancy reduces or inhibits totally the growth ability of buds. Dormancy release and budburst in Scandinavian Betula pendula Roth. and B. pubescens Ehrh. ecotypes were studied in controlled environments. There was a gradual decline in the heat-sum requirement for budburst with increasing chilling time. Two main clines in time of dormancy release appeared in ecotypes of different geographic origin, a latitudinal cline and a coastal-inland cline in which the duration of dormancy increased southwards and towards the coast. In addition, dormancy was later alleviated in high-altitude than in lowland B. pubescens ecotypes. In late autumn, after 44 chilling days, time to budburst at 15C was less in plants chilled at 0C than in plants chilled at 10C, indicating that 0C was most effective for dormancy release. In January, after 105 chilling days, however, dormancy release was completed, and budburst was earliest in plants chilled at 10C. At this stage there were no detectable differences in effectiveness between fluctuating and corresponding constant temperatures (6 to 21C) in promoting growth and budburst in B. pubescens. Long photoperiods significantly reduced time to budburst in partly dormant buds, but had no effect when dormancy was fully released