Populations Of Abies Research Articles

Holocene fire frequency variability in Vesijako, Strict Nature Reserve, Finland, and its application to conservation and management

Fire disturbance is considered paramount for regeneration and biodiversity in the boreal forest with prescribed burning widely advocated in present day forest management. Palaeoecological knowledge is beneficial in understanding the role of fire as a driver of past vegetation dynamics. We use a sedimentary pollen and charcoal record to reconstruct 5000years of fire and vegetation history from a small forest hollow (approximate area 12m2) in the Vesijako Strict Nature Reserve, currently one of the few remaining old-growth forest stands in southern Finland. Results indicate three distinct periods in the environmental history (1) 5000–2000cal. yrs. BP; semi-natural low frequency (430year return period), low intensity fires in a diverse mixed stand with little evidence of anthropogenic disturbance and an expanding Picea abies (Norway spruce) population (2) 2000–750cal. yrs. BP; anthropogenic-driven high frequency (180year return period), high intensity stand-replacing fires in a low diversity stand with evidence of slash and burn cultivation and a decline of Picea population, (3) 750cal. yrs. BP to present day; fire absence through a reduction in human-induced fire or active fire suppression and the expansion of the currently dominant Picea forest. The changing fire frequency has had a major influence on the forest composition during the last 5000years. The loss of floristic diversity is associated with an increase in the human use of fire and without this human interference the previously high biodiversity in the stand may have remained up until the present day. If fire remains absent in Vesijako then it is likely that the Picea population will continue to dominate in the stand supporting a negative feedback mechanism that will result in lower frequency, higher intensity fires in the future.

Deciphering Holocene genetic diversity loss in subalpine Picea abies populations in the Carpathian Mts (Romania): a novel approach combining ancient DNA and pollen analysis

Deciphering Holocene genetic diversity loss in subalpine Picea abies populations in the Carpathian Mts (Romania): a novel approach combining ancient DNA and pollen analysis

Relationship between Seed Germination and Catalase Enzyme Activity of Abies taxa from Turkey

Reactive oxygen species (ROS) are involved in various aspects of seed physiology. Their generation, which occurs during seed desiccation, germination and ageing, may lead to oxidative stress and cellular damage, resulting in seed deterioration. However, cells are endowed with detoxifying enzymes and antioxidant compounds that scavenge ROS and participate in seed survival. The detoxifying mechanisms play a key role in completion of seed germination and seed storability. The enzyme catalase has been employed for determining viability of seeds. The plan of the present work was to explore the relationship between catalase activity and germination of four Abies taxa. For this purpose, seeds which belong to four Abies taxa (Abies nordmanniana subsp. equi-trojani, A. cilicica, A. nordmanniana ssp. bornmuelleriana, A. nordmanniana ssp. nordmanniana) collected from different provenances in 2010 and 2011 harvesting years were used. Germination percentages and catalase enzyme activities of different Abies taxa were measured. Our results demonstrate that Abies seeds had different germination percentage and catalase enzyme activity. Abies nordmanniana subsp. equi-trojani seeds which are collected from Edremit-Gurgendag have higher germination percentage and catalase activity (P<0.05). Other populations of Abies did not differ from each other. In a conclusion, high activity of catalase enzyme refers to viability and quality of seed in Abies taxa.

Genetic Variability of Seed Characteristics of Abies Populations from Turkey

Fir (Abies) species occupies 626.647 ha of forestland which constitutes 3 % of total forest areas in Turkey. There are five native taxa belonging to this genus growing in pure and mixed stands in the country. Three of these taxa(Abies nordmanniana subsp. bornmulleriana, Abies nordmanniana subsp. equi-trojani, Abies cilicica subsp. isaurica) are endemic and considered as low risk (LR) species. Four different morphological characters of seeds were studied from 9 origins (Pozanti-Ulukisla, Bolu-Kokez, Akyazi-Dokurcun, Kizilcahamam-Guvem, Torul-Orumcek, Şavsat-Velikoy, Şavsat-Yayla, Edremit- Gurgendag, Can-Can) belonging to 4 taxa. 20 individuals were sampled from each individual for each population, and measurements were done for 20 seeds/individual. Seed characteristics of A. cilicica were significantly different than other three taxa. Weight of 1000 seeds was the heaviest in A. cilicica (143,70 gr) and the lightest in A. nordmanniana (6,6 gr). Average seed width, length and diameter of all populations were calculated as 6,54 cm, 11.97 cm and 3,34 cm, respectively. Seed weight were significantly correlated (P<0,01) with seed diameter and seed length. The dendrogram constructed by cluster analysis of populations were based on Squared Euclidean Distance and Nearest Neighbor Method. The dendrogram was divided into two main clusters. The first cluster contained only A. cilicica population and the second cluster contained other populations grouped according to taxa.

Reactive species, antioxidants and cold tolerance during deacclimation of Picea abies populations

Seasonal changes in levels of reactive oxygen species (ROS), low-molecular weight antioxidants and activities of antioxidant enzymes were analyzed in relation to the freezing tolerance of 1-year-old needles from four populations of Norway spruce. Throughout the study period (from January until May), no significant changes were observed in the superoxide anion radical (O2·−) or hydrogen peroxide (H2O2) levels in the needles. By contrast, a marked reduction was observed in concentrations of low-molecular weight antioxidants, including flavonoids (FL), ascorbic acid (AsA) and slight glutathione (GSH), during deacclimation. The activities of superoxide dismutase (SOD) (EC. 1.15.1.1.) and guaiacol peroxidase (PO) (EC. 1.11.1.7.) also decreased significantly. The activity of catalase (CAT) (EC. 1.11.1.6.) did not change significantly. Levels of low-molecular weight antioxidants (AsA, FL and GSH) and SOD activity were correlated significantly with freezing tolerance in the studied populations. The reactions were similar in all populations. This suggests that the response of the antioxidant system depends more strongly on climatic conditions than on population origin. The ability of spruce trees to cope with active oxygen species is discussed as an aspect of defense and a factor associated with freezing tolerance.

Post-glacial history and introgression in Abies (Pinaceae) species of the Russian Far East inferred from both nuclear and cytoplasmic markers

Aim The main aim of the present study is to infer the post-glacial history of Abies species from north-east Asia and to test the hypotheses that coastal Abies populations suffered less from climatic fluctuations during Pleistocene glacial periods than their more continental counterparts, and that Sakhalin was a major area of introgression. Location Natural ranges of the fir species Abies nephrolepis, Abies sachalinensis and Abies holophylla in the Russian Far East, and of Abies gracilis, which is endemic to the Kamchatka Peninsula. Methods Nineteen populations were sampled for allozyme analysis. Seventeen of these populations were also screened for variation at two paternally inherited chloroplast DNA microsatellite loci (cpSSR) and variation at one maternally inherited mitochondrial marker (nad4-3/4). Finally a subset of 11 populations was analysed with amplified fragment length polymorphism (AFLP). Comparisons were made with already available Abies sibirica data. For all sets of markers, we estimated genetic diversity and differentiation using an analysis of molecular variance (AMOVA). Population clustering was assessed with a Bayesian approach implemented in structure v.2.3. Results Among the three major species, A. sibirica, A. nephrolepis and A. sachalinensis, A. sachalinensis demonstrated the highest cytoplasmic and nuclear diversity and the most continental species, A. sibirica, the lowest. Both nuclear and mitochondrial DNA markers revealed the presence of a transitional zone on Sakhalin Island between A. nephrolepis and A. sachalinensis of south Sakhalin. The structure analysis delivered very clear results confirming the admixed origin of A. sachalinensis, with a genetic contribution from A. nephrolepis. No variation in cytoplasmic markers was found in A. gracilis, suggesting the occurrence of a recent bottleneck. Main conclusions There is a clear reduction of genetic diversity in Abies species from the Pacific coast into the continent. The higher diversity in A. sachalinensis could have two causes: a larger effective population size in the islands due to relatively stable climatic conditions and consequently less pronounced demographic fluctuations in population size and/or hybridization with continental and Japanese populations. Sakhalin Island is a major transitional zone for conifer species. Finally, the fir from Kamchatka, A. gracilis, should be regarded as a separate species closely related to the A. nephrolepis–A. sachalinensis complex.

A new Late-glacial and Holocene record of vegetation and fire history from Lago del Greppo, northern Apennines, Italy

Detailed Late-glacial and Holocene palaeoenvironmental records from the northern Apennines with a robust chronology are still rare, though the region has been regarded as a main area of potential refugia of important trees such as Picea abies and Abies alba. We present a new high-resolution pollen and stomata record from Lago del Greppo (1,442 m a.s.l., Pistoia, northern Apennines) that has been dated relying on 12 terrestrial plant macrofossils. Late-glacial woodlands became established before 13000 cal b.p. and were dominated by Pinus and Betula, although more thermophilous taxa such as Quercus, Tilia and Ulmus were already present in the Greppo area, probably at lower altitudes. Abies and Picea expanded locally at the onset of the Holocene at ca. 11500 cal b.p. Fagus sylvatica was the last important tree to expand at ca. 6500 cal b.p., following the decline of Abies. Human impact was generally low throughout the Holocene, and the local woods remained rather closed until the most recent time, ca. a.d. 1700–1800. The vegetational history of Lago del Greppo appears consistent with that of previous investigations in the study region. Late-glacial and Holocene vegetation dynamics in the northern Apennines are very similar to those in the Insubrian southern Alps bordering Switzerland and Italy, across the Po Plain. Similarities between the two areas include the Late-glacial presence of Abies alba, its strong dominance during the Holocene across different vegetation belts from the lowlands to high elevations, as well as its final fire and human-triggered reduction during the mid Holocene. Our new data suggest that isolated and minor Picea abies populations survived the Late-glacial in the foothills of the northern Apennines and that at the onset of the Holocene they moved upwards, reaching the site of Lago del Greppo. Today stands of Picea abies occur only in two small areas in the highest part of the northern Apennines, and they have become extinct elsewhere. Given the forecast global warming, these relict Picea abies stands of the northern Apennines, which have a history of at least 13,000 years, appear severely endangered.

Invasion of Norway spruce (Picea abies) and the rise of the boreal ecosystem in Fennoscandia

Summary 1. Norway spruce ( Picea abies ), one of the dominant tree species in Eurasia, has spread slowly westward in northern Europe, invading eastern Finland about 6500 calibrated years ago (cal. years BP), eastern central Sweden about 2700 cal. years BP and southern Norway about 1000 cal. years BP. Its spread is the most recent and best constrained invasion of a main tree species in northern Europe and allows an assessment of colonization patterns and associated competitive replacement processes. 2. We analysed five selected high-resolution pollen accumulation rate (PAR) -records along a 700-km long transect in the direction of P. abies invasion from eastern Finland to central Sweden across the present P. abies - and Pinus sylvestris- dominated southern boreal zone. 3. Our results show that the P. abies population increased in size from the time of the initial expansion to levels comparable with the modern in 100‐550 years. At each site P. abies invaded a dense, intact Pinus ‐ Betula ‐ Alnus forest, mixed with temperate deciduous taxa, particularly Tilia cordata and Corylus avellana . The resident mixed forest provided no or weak resistance to the colonization of P. abies , and the variable population growth rate was therefore not caused by compositional differences in the resident forest but by other, possibly local edaphic factors. 4. Of the taxa that formed the resident forest, T . cordata responded most strongly to the invasion of P. abies . This suggests that the mid-Holocene T. cordata population decline was not directly climateinduced but resulted from competitive replacement due to overlapping ecological niches with P. abies , a stronger competitor. 5. Synthesis . The rise to dominance of P. abies was caused not only by its rapid population growth but by associated competitive suppression of other taxa, leading to a major ecosystem change from a mixed conifer-deciduous forest to the modern P. abies - and P. sylvestris -dominated boreal conifer forest in central Fennoscandia. This competitive suppression by P. abies is still reflected in the scattered occurrence and generally weak performance of T. cordata in the boreal zone of Europe and may influence its distribution and abundance patterns under predicted future climate scenarios.

Studies on isozyme variation in marginal and central populations of Picea abies.

Two delimited populations of Picea abies, each comprising about 50 individuals have been analysed with regard to three different enzyme systems, esterase (EST), leucine-amino-peptidase (LAP) and acid phosphatase (PHOS). Female gametophytic endosperm tissue dissected from mature seed has been used for all three isozyme analyses. As this tissue is haploid, a novel method for distinguishing heterozygotes and homozygotes has been used. The spatial mapping of genotypes in their habitat indicates complete randomness of gene distribution within stands. In two cases (LAP and PHOS), enzyme analyses also indicate strict conformity of allozymes to expected Hardy-Weinberg frequencies. Allele frequencies in the range of 0.3–0.7 for two or more allozymes suggest heavy gene flow, frequency-dependent selection or, possibly, founder effects. In the third enzyme system analysed (EST), there is indication of balanced heterozygosity. There appears to be plenty of genetic variability of allozymes even at the species margin. The adaptive significance of different enzyme systems is briefly discussed.

Genetic variation in eleven populations of Picea abies as determined by isozyme analysis

Eleven populations of Picea abies in Sweden were analysed for isozyme variation in four polymorphic loci. Genetic differentiation between geographically isolated populations could be demonstrated, the major part of genic differences occurring in the esterase-A and acid phosphatase-A loci. When populations originating from foreign seeds are involved in comparisons with indigenous populations, higher values of genetic differentiation are found. Genic variability within populations was estimated from “average heterozygosity”, a measure which is based upon the observed gene frequencies. An increase in “average heterozygosity” was found in two populations of foreign origin, which to a certain extent may be due to intercrossing between genomes of different origin.

Pollen stratigraphy, vegetation and climate history of the last 215 ka in the Azzano Decimo core (plain of Friuli, north-eastern Italy)

The pollen record of the long succession of marine and continental deposits filling the subsident north-Adriatic foredeep basin (NE Italy) documents the history of vegetation, the landscape evolution and the climate forcing during the last 215 ka at the south-eastern Alpine foreland. The chronology relies on several 14C determinations as well as on estimated ages of pollen-stratigraphical and sea-level event tie-points derived from comparison with high-resolution marine records, speleothemes and ice cores. Mixed temperate rainforests persisted throughout MIS 7a–7c, being replaced by conifer forests after the local glacioeustatic regression during early MIS 6. The Alpine piedmont facing the Adriatic foredeeep was glaciated at the culmination of the penultimate glaciation, as directly testified by in situ fluvioglacial aggradation related to the building of a large morainic amphitheatre. The pollen record allows correlation with other European records and with the IRD from N-Atlantic and off Iberia, thus the duration of the penultimate glacial culmination at the southalpine fringe is estimated less than 13 ka between 148 ± 1 and >135 ka. The site was not reached by the Last Interglacial maximum sea transgression and enregistered a typical, though incomplete, Eemian forest record, lacking Mediterranean evergreen trees. A complex sequence of stadial–interstadial episodes is reconstructed during the Early and Middle Würm: major xerophyte peaks match IRD maxima occurred during Heinrich events in deep-sea cores offshore Iberia and in the N-Atlantic and allows to frame lumps of interstadial phases, marked by Picea peaks, each one including several DO warm events. Broad-leaved thermophilous forests disappeared from the north-eastern plain of Italy at the end of the Early Würm, whereas reduced populations of Abies and Fagus probably sheltered even during the Last Glacial Maximum. A renewed fluvioglacial in situ deposition between 30.4 ± 0.4 and 21.6 ± 0.5 ka cal BP sets the time and duration of the last glacial culmination in the pedemontane morainic amphitheatre. Palynomorphs from Plio-Pleistocene marine successions were reworked by glacier erosion and deposited in the lowland during both the penultimate and the last deglaciation phases. This explains a bias affecting previous pollen records from the region.

Protein Polymorphism between 2 Picea abies Populations Revealed by 2-Dimensional Gel Electrophoresis and Tandem Mass Spectrometry

In species with high gene flow and consequent low interpopulation differentiation over wide geographic ranges, differential gene expression along ecological gradients often reveals adaptive significance. We investigated potential differences in protein expression between Picea abies ecotypes adapted to contrasting altitude conditions. Protein expression patterns were compared between needles and roots of 2-month-old P. abies seedlings by means of 2-dimensional electrophoresis. Proteins exhibiting differential expression between the 2 ecotypes were analyzed by tandem mass spectrometry. A total of 19 proteins exhibited qualitative or quantitative polymorphism between the 2 populations. These proteins exhibited organ-specific expression, and the level of interpopulation protein polymorphism was organ dependent. Among differentially expressed proteins, we identified proteins involved in photosynthesis, photorespiration, root tracheary element differentiation, and transmitochondrial membrane transport. Our results show that P. abies seedlings from locally adapted ecotypes exhibit consistent differences in protein expression. The expression polymorphism of some of these proteins has potential adaptive significance.

Genetic diversity at chloroplast microsatellites (cpSSRs) and geographic structure in endangered West Mediterranean firs (Abies spp., Pinaceae)

We investigated patterns of genetic variation within and among the eight extant populations of the genus Abies in the western Mediterranean Basin. Using six chloroplast microsatellite (cpSSR) loci, a total of 22 alleles and 34 haplotypes was found among 225 individuals. The analyzed populations showed high levels of genetic diversity (mean He = 0.84). Two clearly separated main groups corresponding to the three Spanish and the five Moroccan populations, respectively, were distinguished. A phylogeographic signal was evident and a Mantel test revealed a strong positive correlation between geographic and genetic distances of the eight populations. Analysis of Molecular Variance (AMOVA) assigned 85% of the total genetic variation to differences between continents. Within each continent, populations were remarkably little differentiated with the exception of one highly divergent Moroccan stand; the origin of this divergence requires further investigation. Our results document a strong effect of the Strait of Gibraltar on Abies differentiation in this region, whereas the high diversity within and the low differentiation among populations on each side point to a certain level of pollen‐mediated gene flow among the extant stands. On the other hand, our analysis indicates that the population formerly assigned to the species A. tazaotana is, in fact, genetically very close to most A. marocana stands. We discuss implications of the observed population structures for conservation and management of West Mediterranean Abies taxa.

Neighborhood interactions influencing tree population dynamics in nonpyrogenous boreal forest in northern Finland

Open-canopy moss-rich woodlands dominated by Picea abies and Betula pubescens in northern Finland may undergo cyclic development with reciprocal replacement of the tree species due to the positive feedbacks on soil conditions. Although relations to the abiotic environment are well understood, intra- and interspecific interactions during development of sparse boreal forests have received less attention. We studied tree regeneration, growth and survival with respect to size and density of neighboring trees in four stands representing roughly four stages of the Picea–Betula forest cycle. We conducted spatial analysis (Ripley’s K-function) of mapped locations of live and dead stems to reconstruct the distribution of stems prior to mortality, and to infer possible causes of tree population decline. The prevalence of standing dead stems enabled us to test if mortality was associated with density and size of neighboring trees. Logistic regression was used to test for relationships between tree survival and local crowding indices. We also examined spatial autocorrelations of individual size characteristics to determine the mode and spatial extent of tree interactions. Picea abies had reduced recruitment in open areas occupied by mosses and dwarf-shrubs, and preferentially regenerated near B. pubescens, whereas B. pubescens formed small clumps (and occasionally these consisted entirely of stems from a single tree) that showed local repulsion from large P. abies trees. Size of neighboring trees was the primary determinant of individual growth and survival, whereas neighborhood density per se had only a weak effect. Picea abies had negatively correlated sizes among close neighbors (0–4 m radius) indicating that dominant trees suppress their smaller neighbors. Negative autocorrelations prevailed at the transition stages where the patches of smaller trees were concentrated around evenly spaced large trees. Tree sizes became spatially independent at the mature phase. We hypothesize that both low light and soil nutrient availability causes the P. abies population decline. Dominant trees in this high latitude forest have large light depletion zones and shallow root system to promote strong above- and below-ground competition with younger trees. Higher mortality rates within canopy patches were not compensated for by recruitment in gaps, causing P. abies population to decline steadily.

Abies population dynamics simulated using a functional–structural tree model

AbstractA functional–structural model, PipeTree, based on Abies population data has been developed to reveal the interactions among processes at physiological, individual and population scales. Using field measurements obtained in a comprehensive series of research studies on subalpine Abies forest stands on Mt. Shimagare during the 1950s to 1980s, we designed the structural components and physiological process models for PipeTree. The results of the PipeTree simulation support the feasibility of using a functional–structural tree model to evaluate ecosystem performance at the stand level. PipeTree generates patterns similar to those in real subalpine forests, such as diameter–height relationships and time changes in basal area. After demonstrating the validity of the dynamics of a PipeTree population, we applied a sensitivity analysis under a productivity‐enhanced environment in which the maximum photosynthetic rate (Pmax) of PipeTree foliage was increased by 50% (caused, for example, by CO2 enrichment). The results of Pmax enhancement simulation show that the 50% increase in Pmax doubles the net primary production (NPP) in the PipeTree stand. These results suggest the importance of canopy structure in evaluating the function of terrestrial ecosystems.

RAPD and mtDNA variation among autochthonous and planted populations of Picea abies from the Vosges mountains (France) in reference to other French populations

RAPD phenotypic analysis (AMOVA and FCA) allowed to determine three groups among the Picea abies French genetic resources: the Vosges (autochthonous and planted populations), the Alps/Jura and the Southern Alps. The within-population values of gene diversity (He) did not differ significantly. MtDNA analysis at locus mh44 has revealed that one major size variant, characteristic of the Alpine domain, was found in the six autochthonous populations investigated. The planted population showed two additional mtDNA types leading to support the hypothesis of a transfer of material from east of Europe in the late 19th century.

A morphometric and chemosystematic study on the Abies Miller (Fir) species in Turkey

Naturally distributed Abies (Fir) Miller taxa comprise five subspecies belonging to two species (A. nordmanniana subsp. nordmanniana, A. n. subsp. bornmuelleriana, A. n. subsp. equi-trojani, A. cilicica subsp. cilicica, A. c. subsp. isaurica) in Turkey. A multi-level study of the genus Abies is presented. Infrageneric states and chemosystematic relationships are discussed by using some selected essential oil components and morphometrical characters. Morphologic and morphometric analysis are carried out on 20 Abies population and essential oil analysis on the twig with needle are carried out by using GC. techniques. The qualitative major constituents are found as same in the whole studied species but their quantitative content varies significantly. Inter and intra- populational variations are found at the high ratio in the Abies taxa. The results are presented in graphical form, allowing patterns of variable intercorrelations and compared with phylogenetic patterns. Tree to tree variation of quantitative terpene composition of the leaf oil is sufficiently to permit chemosystematic discussions and understanding evolutionary phenomenon in the light of literatures.

Response of Picea abies populations from elevational transects in the Polish Sudety and Carpathian mountains to simulated drought stress

The response of 24 Norway spruce populations from a broad elevational gradient to four combinations of watering and temperature was studied in a phytotron experiment. The results of this experiment are important for better understanding possible impacts of global warming on low- and high-altitude populations of Picea abies. The investigated populations showed evidence of clinal variation in height, mass and bud-set parameters in all treatments. The higher the elevation of origin, the earlier the bud-set and the poorer the mass and height of the populations. The interaction of population origin×treatment showed a small percentage variance component, but there was a clear differentiation in reaction of the tested populations to the simulated drought. The low-altitude populations showed a strong negative reaction to the drought stress, whereas the high-altitude ones were more drought tolerant. So if global warming would be accompanied by soil drought, the low-altitude populations would reduce their growth much more than the high-altitude ones. But if global warming would be combined with an adequate increase of precipitation, then low-altitude populations would profit from this climate change more than high-altitude ones.

Genetic variation at chloroplast microsatellites (cpSSRs) in Abies nebrodensis (Lojac.) Mattei and three neighboring Abies species

Abies nebrodensis (Lojac.) Mattei (Sicilian fir) is an endangered species represented by only one population of 29 adult individuals occurring in a limited area of the Madonie Range in northern Sicily (Italy). Taxonomic boundaries between this taxon and the neighboring Abies species are not clear. In this study, we used six chloroplast simple-sequence repeats (cpSSRs) to investigate the population genetic structure and the distribution of chloroplast haplotypic variation in A. nebrodensis and three of the neighboring Abies species: Abies alba (Mill.), Abies numidica (De Lann) and Abies cepha-lonica (Loud.). Our aims were to quantify the level of cpDNA differentiation within the Abies populations and to shed light on the history of A. nebrodensis. Diversity levels based on the haplotype frequency at six cpSSRs were high, especially in A. alba and A. cephalonica. In all, we found 122 haplotypes among the 169 individuals analyzed, and the four species were distinguished from each other by their haplotype composition. The majority of the haplotypes (76%) were detected only once, but in A. nebrodensis seven individuals (41% of the sample population) shared the same haplotype. Moreover, the seven A. nebrodensis individuals with an identical haplotype showed a tendency to be geographically grouped within the population"s limited range. The analysis of molecular variance (AMOVA) showed a significant difference in the level of apportionment of gene diversity between the species A. alba and A. cephalonica (FST=0.191 and 0.012, respectively). AMOVA analysis conducted over all populations from the four species showed that 19% of the total cpSSR variation was attributable to differences among species, 6% was due to differences among populations within species, and 74% to differences within populations. The high percentage of unique haplotypes identified confirms the power of cpSSR haplotype analysis for identifying individual trees in individual Abies populations. Our results indicate that A. nebrodensis differs from the other three Abies species investigated and support its classification as an independent taxon. The results also showed a decreased level of variation in A. nebrodensis and suggested that the species has experienced a genetic bottleneck during the last two centuries.

Variation in Juvenile Growth Rhythm among Picea abies Provenances from the Baltic States and the Adjacent Regions

Knowledge on the pattern of variation in growth rhythm among Baltic Picea abies populations is limited. Growth rhythm of 108 Picea abies provenances from the Baltic states, north-eastern Poland, western Russia, north-western Belarus, Sweden and southern Finland was studied for three growth periods in two nursery trials located in central Sweden and in central Lithuania. Damage by natural frost desiccation was assessed at an age of two years in the Swedish trial. Variation among the Baltic provenances in juvenile growth rhythm traits was essentially clinal over latitude and longitude. According to a multiple regression function, a change in 1° of latitude corresponded to 2.4° degree change in longitude. When moving from the north-eastern part of Poland towards north-east, the seedlings became shorter and more tolerant to frost desiccation with earlier budburst and budset. Photoperiod and temperature climate were identified as the main determinants for the clinal variation among the Baltic populations of Picea abies in growth rhythm traits over the ecological gradients from south to north and from coastalto inland sites.