Search

Several decades ago, many former pastures in Central Europe were afforested or colonized by trees after being abandoned. Knowledge of the effects of tree species on soil properties is important for planning of the composition of future forests. In this regard, a research location in Vrchdobroč (Central Slovakia), which is former agricultural land used as pasture, enables the exploration of ecosystem processes and properties in stands of different tree species after afforestation. The goal of our study was to find out whether changes in soil properties, including soil microbial activity and diversity among different stands, were already observable 45 years after the afforestation, and how the effects differed among stands of different tree species. The study was conducted in the pure stands of Norway spruce (Picea abies L. Karst.), Douglas fir (Pseudotsuga menziesi (Mirb.) Franco), European beech (Fagus sylvatica L.) and sycamore maple (Acer pseudoplatanus L.). Multivariate analyses of physico-chemical soil properties indicated an overlap between the soils under the Douglas fir and the spruce, but a clear separation of beech from sycamore. In general, both microbial activity and diversity were, surprisingly, highest under the Douglas fir, followed by the sycamore, with the beech and the spruce showing mostly lower values.

Single-nucleotide polymorphisms in seven candidate genes for drought and heat tolerance identified in earlier studies were studied in 13 populations of Abies alba Mill. covering the eastern and southeastern half of the distribution range. Trees were planted in a provenance trial plot of the international experiment IUFRO 2005 in Hertnik, Slovakia. In parallel, genotyped trees were also scored for physiological traits (PSII thermotolerance, chlorophyll a fluorescence kinetics, partly gas exchange, assimilatory pigments, needle osmotic potential). For the detection of natural selection imprints, we used different methods: analysis of FST-outliers, testing of SNP–climate associations and SNP–phenotype associations. FST-outlier analysis revealed 2 SNPs with signals of selection. Moreover, three other SNPs showed significant association with latitude or bioclimatic variables; one of them (C/T polymorphism in a gene coding for serine/threonine phosphatase) was significantly associated with needle osmotic potential and marginally with other drought-related physiological traits. That may indicate its role in drought-stress response. In addition, T/C polymorphism in a gene coding for reduced epidermal fluorescence 4 was found to be involved in heat-stress response. However, migration history seems to be a more important driver of differentiation at SNPs in the studied candidate genes than recent adaptation.

The assisted migration of resistant seeds and seedlings may be a key to mitigating the effects of climate change on the productivity and composition of forest ecosystems. These efforts require an understanding of the intraspecific variability in the response of trees to extreme weather events such as heat waves. In this study, we assessed the geographical patterns of photosystem II (PSII) performance and thermostability in European beech (Fagus sylvatica L.) and whether intraspecific differences are associated with climate of origin. Two provenance trials with starkly contrasting climates were used for this study. Leaves were sampled both before and after natural heat stress exposure. Rapid chlorophyll fluorescence kinetics was used to evaluate PSII performance and PSII thermostability after simulated heat stress. The performance of PSII at 30 °C, which is still considered a non-damaging temperature, was generally slightly better at the warmer location than at the colder location. The populations originating closer to the Slovenian refugium, as well as those growing closer to their site of origin, showed better performance of PSII but not greater thermostability. The effect of simulated heat stress was much stronger in the colder plots compared to the warmer plots, but only for previously stressed trees. Likewise, we found indicators of geographical patterns of thermotolerance as well as relationships between thermotolerance and climate of origin mostly for trees exposed to natural heat. While the origin of provenances partly explained the variation among provenances, acclimation driven by climate played a major role in the response to heat stress. In beech, PSII seems to have a potential for coping with high temperature.

Current climate changes can led to a decline of local beech populations fully adapted to previous climate conditions. In this context, the issue of variation in adaptive traits becomes important. A field experiment with 18-year-old trees of Fagus sylvatica L. was conducted on provenance plot located in Tale (Central Slovakia), where physiological responses of five beech provenances originating from contrasting sites along an altitudinal gradient from 55 to 1100 m a.s.l. across the range of the natural beech distribution were studied. Stomatal characteristics, parameters of chlorophyll a fluorescence and gas exchange parameters were determined. Overall, we observed a significant increase in physiological performance at the leaf level with increasing altitude of origin. Provenances from the higher altitudes showed higher CO2 assimilation rate, stomatal density, potential conductance indices and photochemical efficiency, and lower capability for dissipation of energy by heat. A similar pattern of response was recorded in relation to the precipitation regime of sites of origin. Moreover, in the context of the temperature regime, several negative trends were observed.

The acclimation of silver fir to the conditions of the plantation sites has greater influence on PSII thermostability and performance than does on local adaptation. Forest ecosystems are frequently exposed to heat stress, which adversely affects their growth, performance, and ultimately survival. The knowledge of physiological responses to heat can help mitigate the effects of climate change by facilitating the choosing of suitable reproductive material for future reforestation programs. However, the intraspecific variation of adaptive traits, including the response to heat, has not been well documented. Therefore, we attempted to determine how PSII photochemistry of different silver fir (Abies alba Mill.) provenances varies in responses to heat stress and to reveal if intraspecific variation in PSII performance and thermostability is more affected by the climate of provenance origin or the plantation site. We tested 17 fir provenances sampled at two contrasting international provenance trial sites: Hertnik in Slovakia (390 m a.s.l.) and Kaprun in Austria (1100 m a.s.l.). Short-term heat stress was simulated for seven temperatures ranging from 20 to 51 °C using a water bath. The PSII thermotolerance was assessed via parameters of chlorophyll a fluorescence derived from the OKJIP transient. We observed several climatic variables of the provenances that significantly affected the photochemistry performance and thermostability of PSII, reflecting an additive hereditary basis. Almost all measured parameters varied significantly between trial plots and showed significant trial-by-provenance interactions pointing to acclimation triggered by the different conditions at the trial plots. Overall, the performance of PSII under non-stressing conditions and after heat treatment was better for provenances growing at the warmer trial site at Hertnik.

The study reviews trait inheritance, which is in contradiction with the rules of Mendelian genetics, and which was object of controversies among biologists (sometimes with grave political consequences) in the USSR and Sovietcontrolled countries in the 1930s-1960s. “Carryover” or “memory” effects of the climate, to which maternal trees are exposed during seed development, on phenological behavior and other adaptively relevant traits of their offspring in conifers are mentioned; similar effects are associated with the germination and early growth environment. Molecular mechanisms underlying these effects include covalent modifications of DNA or DNA-associated proteins (cytosine methylation, various types of histone modifications), micro-RNAs and small interfering RNAs. Tools for the identification of these modifications are reviewed with a focus on cytosine methylation, along with an overview of the hitherto knowledge on the occurrence of DNA modifications in forest trees. The practical implications of epigenetic inheritance in forest trees are discussed with the focus on the adaptation to climate change and legislation on forest reproductive materials.

Wind disturbance is a major natural driver of forest dynamics in a large part of Europe and can affect soil properties in different ways and for different time. The present study focuses on the effects of post-disturbance management of windthrow plots in the Tatra Mountains, Slovakia, on soil microorganisms ten years after the disturbance. Their comparison with the microbial characteristics at a new windthrow plot caused by strong wind in 2014 was also carried out. Three research plots differing in the way of their management after the windstorm in 2004 (EXT, salvage plot; FIR, salvage plot affected by fire; NEX, unsalvaged plot) and the plot destroyed by strong wind in May 2014 (REX) were used for study. Ten soil samples were taken from the mineral A-horizon (depth: 0-10 cm) at each plot in autumn 2014. In soil samples, soil chemical and microbial characteristics (microbial biomass C, basal and substrate-induced respiration, N-mineralisation, catalase activity, richness and diversity of soil microbial functional groups based on the Biolog approach) were determined. Ten years after the disturbance we still observed significant differences in microbial characteristics between FIR and the other plots, with higher microbial activity at the FIR, while no significant differences were found among the other plots. The results indicate that at a higher altitude the effect of fire on soil microorganisms is more distinct than removing or not removing of fallen trees and persists even over a decade.

Although European beech (Fagus sylvatica L.) is one of the most widespread and ecologically and commercially most important deciduous trees in Europe, little is known about its adaptive genetic variation. We explored single-nucleotide polymorphism (SNP) variation in candidate genes for budburst and drought resistance in beech populations sampled across most of the distribution range, represented in an international provenance trial. SNP variation was monitored for six candidate genes, in 114 individuals from 19 natural populations. Population structure was deduced from the analysis of 20 nuclear microsatellite markers. Different methods to detect imprints of natural selection were used (F ST-outlier, SNP-climate regression, association tests). The F ST-outlier approach identified the COV gene with unambiguous signal of selection, which is an orthologue of Arabidopsis gene for a membrane protein previously reported as phenology-related. Based on environmental association analysis at the population level, the dehydrin gene was found associated with drought-related climatic variables. At the individual level, dehydrin gene also showed a significant association with chlorophyll fluorescence parameters, which are considered stress markers. The importance of the knowledge of physiological variation and geographical patterns of adaptive genetic variation for guiding reproductive materials transfer under climate change is stressed.

In the context of Europe, the southern peninsulas including the Balkans are considered hotspots of diversity. They preserved substantial parts of tree species and genera occurring in Europe during the Tertiary, as the effects of the Quaternary glaciations on species richness were not as severe here as in more northerly regions. The Balkans also harboured glacial refugia of most European trees, and this was probably the reason for a premature suggestion that this region was the main source for the Holocene recolonization of Central and Eastern Europe. However, studies based on a combination of paleobotanical and genetic evidence showed that this was an exception rather than a rule. In most tree species, the Balkan refugia have not effectively contributed to current gene pools. In spite of this, empirical studies have documented that genetic diversity in the Balkan region is generally higher than elsewhere in Europe, which can be attributed to a high number of refugia in this area harbouring differentiated genetic lineages, and high environmental heterogeneity. This makes the Balkans an important source of genetic material for forestry, especially in the light of the ongoing climate change.

Structural and ultrastructural traits of leaf xylem vary among European beech ( Fagus sylvatica L.) provenances in relation to climate. High tracheary element lumen area was observed in central Europe and decreased towards the range margins, while tracheary element density displayed opposite trend. Leaf anatomy and xylem cell-wall deformation were associated with climate continentality at the sites of origin. Understanding structural and physiological properties of tree populations adapted to local climate in response to climate may be of direct relevance for forestry. Identifying patterns of heritable geographical variation and phenotypic associations of leaf-anatomical, vascular and cell-wall properties in European beech, a dominant tree species of European forests. Fifteen beech populations planted in a common-garden test were studied employing gas exchange and chlorophyll a fluorescence measurements as well as light and atomic force microscopies of leaf samples. Nanomechanical properties of leaf-xylem cell walls did not show a clear geographical trend, but were correlated with the temperature seasonality of the site of origin. Populations from eastern Germany, northern Poland and the Czech Republic showed lower tracheary element lumen area and higher tracheary element density compared with the other populations, while xylem conductivity negatively correlated with latitude. Thickness of leaf parenchyma layers increased towards the East and, consequently, correlated with temperature indicators of climate continentality. No correlation between structural and physiological traits was observed. The observed trends and associations with climate indicate adaptive variation of the studied traits.

The knowledge of the extent of local adaptation is essential for forest reproductive material transfer, designing gene conservation programs and measures for mitigation of the ongoing climate change. A common methodology for assessing selection underlying local adaptation is the comparison of differentiation at neutral markers (measured by F ST) against quantitative traits (measured by Q ST). We investigated differentiation in phenology, height and diameter growth, and parameters of photosynthesis and water regime in a widespread European broadleaved tree, European beech (Fagus sylvatica L.). As the assessment of Q ST requires known pedigree structure of the tested populations, it was approximated by the coefficient of phenotypic differentiation P ST. For all phenology traits, especially budburst timing, there is a strong and reliable evidence of local adaptation as indicated by P ST > F ST. On the other hand, P ST was generally smaller than F ST for most growth and physiological traits, but the evidence for uniform selection or canalization acting at genes underlying these traits is generally absent or weak. Possible heritable basis of phenological differentiation is discussed, and implications for the current EU legislation on forest reproductive material are drawn.

Climate change may endanger not only yield and fulfilling the social functions of European forests, but even the survival of several tree species. The study emphasises the complexity of climatic factors and physiological mechanisms, which may potentially endanger the persistence of tree populations and which cannot be reduced to problems of drought and temperature increase. A substantial inter-population variation in traits associated with the response to climatic stress, observed in provenance experiments, is a prerequisite for the choice of proper forest reproductive material (FRM) in reforestation as a strategy of climate-change mitigation. Assisted migration, i.e., transfer of FRM from source regions, currently characterised by such climate characteristics, which are expected in the target regions in the future, requires knowledge of key stress factors (depending on the climate scenario), physiological processes associated with the adaptation to this stress, identification of genes and eventually epigenetic mechanisms, controlling adaptation processes, and finally mapping of genetic and/or epigenetic variation in key genes. For most tree species, such information is not yet available. Therefore, assisted migration under such information uncertainty needs to be complemented by in situ gene conservation measures to preserve the possibility of reversing the effects of eventual erroneous decisions on FRM transfer.

Gene flow among individual trees of Pinus sylvestris and P. mugo putative hybrid swarms in Slovakia was fol-lowed at four localities using the species-diagnostic cpDNA trnV-trnH/Hinf I restriction profile. Variable proportions of P. sylvestris and P. mugo haplotypes were revealed among the sampled localities. Low between-habitus consistency of the trees and their cpDNA haplotypes indicates the hybrid nature of the swarms. Molecular analy-sis based on mutual comparison of the haplotypes of a given tree and its embryos suggests direct and recipro-cal hybridization between trees of the P. sylvestris and P. mugo haplotypes. Besides conspecific embryos resulting from hybridization of trees with the same haplotype (P. sylvestris × P. sylvestris and P. mugo × P. mugo), hybrid embryos of P. sylvestris × P. mugo (8.03%) and P. mugo × P. sylvestris (11.50%) were also detected in open-pollinated offspring. The results are discussed from the standpoint of primary and introgressive hybridization between the parental species.

The genus Abies is represented in southern Balkans by A. alba, A. cephalonica, and A. borisii-regis. To infer the status of southern-Balkans firs, as well as the extent and patterns of introgression within this taxonomical complex, we analyzed genetic variation patterns of 29 indigenous fir populations in Bulgaria, Macedonia, Greece, and Calabria using a combination of maternally and biparentally inherited markers. Three mitochondrial lineages were observed, one comprising Calabrian populations and two distributed in the Balkans, coinciding with A. alba and A. cephalonica. The boundary between lineages is sharp; only two populations containing a mixture of haplotypes were found. Bayesian analysis of population structure based on seven nuclear microsatellite (nSSR) loci revealed the existence of two clusters whose proportions exhibited a latitudinal cline with a width of 2.3° ( ≈ 255 km). Populations in the center of the latitudinal cline exhibit the most symmetrical, the flattest, and the broadest distrib...

The aim of the study was to analyse provenance tests of beech situated close to the south-eastern continental limits of the species, in order to develop a response model of adaptation and plasticity of populations on evolutionary-ecological basis, following sudden climatic changes, as a result of transplanting. Modelling of juvenile height was performed with the help of ecodistance variables. The concept of transfer analysis and ecodistance is based on the hypothesis that phenotypic response to macroclimatic changes depends on the inherited adaptive potential of the population and on the magnitude and direction of experienced environmental change. In common garden experiments, the transfer to the planting site is interpreted as simulation of environmental change. The application of ecodistance of transfer for evaluating common garden experiments provides much needed quantitative information about response of tree populations to predicted climatic changes. The analysis of three field experiments of European beech in SE Europe indicates that macroclimatic adaptation patterns exist in juvenile growth and justify restrictions of use of reproductive material on the basis of evolutionary ecology. The presented model illustrates that response to climatic change is regionally divergent, depending on testing conditions and on hereditary traits. In particular, climatic warming in the central-northern part of the range may lead to production increase. However, under the stressful and uncertain conditions at the lower (xeric) limit of the species, growth depression and vitality loss are predicted. The deviating behaviour of higher elevation provenances support their separate treatment. The results may be utilised in climate change adaptation and mitigation policy in forestry and nature conservation, to revise rules for use of reproductive material and also for validating evolutionary and ecological hypotheses related to climate change effects.

Na plochách v Tatranskom národnom parku, ktoré boli postihnuté veternou kalamitou v roku 2004 a požiarom v roku 2005, sme študovali pôdne mikrobiálne spoločenstvo. Cieľom tejto práce je porovnať odozvu pôdnych mikroorganizmov na rozdielny manažment plôch a hodnotiť vývoj mikrobiálneho spoločenstva v priebehu rokov 2006-2013. Pôdne vzorky sme odoberali z A-horizontu pozdĺž 90 m dlhého tranzektu na 4 plochách (referenčná plocha, plocha s vyťaženou drevnou hmotou, plocha po požiari, plocha s nevyťaženou drevnou hmotou). V pôdnych vzorkách sme stanovovali bazálnu a potenciálnu respiráciu, mikrobiálnu biomasu, N-mineralizáciu, aktivitu katalázy, abundanciu a diverzitu funkčných skupín pôdnych mikroorganizmov použitím BIOLOG Eco platní. Vo všeobecnosti, najvyššiu aktivitu a biomasu pôdnych mikroorganizmov sme zaznamenali na ploche referenčnej a ploche po požiari. Nezistili sme významné rozdiely medzi plochou vyťaženou a nevyťaženou. Na všetkých kalamitných plochách sme v sledovanom období zaznamenali mierny trend nárastu hodnôt mikrobiálnej biomasy, potenciálnej respirácie a N-mineralizácie, čo poukazuje na proces postupnej obnovy mikrobiálneho spoločenstva na kalamitných plochách.

The unimodal species richness-altitude distribution pattern seems to be universal. To investigate the validity of this phenomenon in homogeneous substrate and vegetation conditions, we sampled beech-dominated forests in five volcanic mountain ranges in the Western Carpathians. European beech (Fagus sylvatica L.) formed monodominant closed-canopy stands at altitudes from 300 to 1,200 m. Along this gradient, the influence of beech on understory plant species richness was expected to be strong and uniform. The shape of the species richness-altitude relationship was analyzed for three datasets: herb layer, shrub layer, and both layers merged together. Contrary to prediction, the studied species richness-altitude relationship was inversely unimodal, with a minimum at intermediate altitudes. Quadratic regression models were statistically significant for all three datasets (P

Changes of soil microbial community caused by the heterogeneity of abiotic and biotic environment were studied in the reserve Dobroc, Slovakia. Data on vegetation, microclimate, soil properties and microbial activity were collected on two linear transects crossing both the core of the reserve and the buffer zone. In contrast to expectations, the variation of most environmental variables was comparable or even higher in the buffer zone than in the old-growth forest. Beta diversity was much higher in the natural forest, which coincided with differentiation patterns of trees and understory plants. Mantel correlations between microbial community indicators and environmental variables showed that soil chemistry and vegetation diversity were the most important determinants of microbial activity. Redundance analysis of microbial data identified potassium content, plant richness and influence of fir as the drivers of functional group composition. Inconsistency of correlations of microbial community characteristics with environmental variables indicates that different processes associated with the demography and functions of microbiota are driven by different environmental factors. Amount and variety of substrates available for decomposition seems to influence microbial community more than microclimate.

The study focused on the temporal dynamics of soil water content (SWC) and soil microbial activity characterized by basal respiration and catalase activity in the litter (OL), fragmented (OF), and humus (OH) subhorizons of the forest floor and the mineral A-horizon, in relation to air temperature and rainfall. The study was conducted at three plots (old-growth Norway spruce (Picea abies Karst.) forest, even-aged mature commercial spruce stand, grassland dominated by Calamagrostis sp.) located in the Biosphere Reserve Polana (Slovakia, 19°28′E, 48°38′N) during four years. SWC as well as microbial activity differed among horizons as well as among plots. Generally, organic horizons in the old-growth forest exhibited higher microbial activity than in the managed forest, but no significant differences were observed for the A-horizon. On the other hand, the A-horizon showed higher catalase activity in the grassland than in both forest stands. The responses of SWC and microbial activity to air temperature and rainfall differed among horizons. SWC responded most sensitively to short-term temperature fluctuations in the OL horizon. In the underlying horizons, cumulative positive effects of high temperature (lasting 5–15 days) were reflected in the basal respiration. SWC responded rapidly to precipitations, but the effect lasted generally not more than 2 days. In contrast, catalase activity was negatively correlated with the precipitation amount; however, with increasing depth this relationship became less distinct.

Gomory, Dusan/0000-0002-9426-4247; Sevik, Hakan/0000-0003-1662-4830; Paule, Ladislav/0000-0002-5097-7472 WOS: 000417754100014 PubMed: 29238533 The eastern-Mediterranean Abies taxa, which include both widely distributed species and taxa with minuscule ranges, represent a good model to study the impacts of range size and fragmentation on the levels of genetic diversity and differentiation. To assess the patterns of genetic diversity and phylogenetic relationships among eastern-Mediterranean Abies taxa, genetic variation was assessed by eight nuclear microsatellite loci in 52 populations of Abies taxa with a focus on those distributed in Turkey and the Caucasus. Both at the population and the taxon level, the subspecies or regional populations of Abies nordmanniana s.l. exhibited generally higher allelic richness, private allelic richness, and expected heterozygosity compared with Abies cilicica s.l. Results of both the Structure analysis and distance-based approaches showed a strong differentiation of the two A.cilicica subspecies from the rest as well as from each other, whereas the subspecies of A.nordmanniana were distinct but less differentiated. ABC simulations were run for a set of scenarios of phylogeny and past demographic changes. For A. xolcayana, the simulation gave a poor support for the hypothesis of being a taxon resulting from a past hybridization, the same is true for Abies equi-trojani: both they represent evolutionary branches of Abies bornmuelleriana. Vedecka Grantova Agentura MSVVaS SR a SAV [VEGA 1/0269/16] Vedecka Grantova Agentura MSVVaS SR a SAV, Grant/Award Number: VEGA 1/0269/16

The effect of 19 environmental variables on species richness of macrophytes was studied in 39 Slovak streams. The studied streams were poor in species; in total, 88 macrophyte taxa were found and the average number of macrophytes per sampling site was 4, ranging from 0 to15. The most frequently occurring macrophytes were filamentous algae (occurrence at 38.6% of sampling sites), followed by Rhynchostegium riparioides (28.4%) and Phalaris arundinacea (19.3%). The strongest environmental gradient in the sampling site detected by factor analysis (factor 1 explains more than 32% variability) is related to the portion of artificial banks, shading by woody vegetation along banks, flexuosity of stream course and the portion of natural land cover in the contact zone of the stream, and can be interpreted as a natural-anthropogenic gradient. The following variables had the highest correlations with species richness of macrophytes: shading by woody vegetation (r=−0.507), portions of artificial bank (r=0.488), flexuosity (r=−0.457) and distance from stream source (r=0.388).

Genetic exchange between divergent lineages of silver fir (Abies alba Mill.) was studied in the Ukrainian Carpathians where two expanding populations originating from different glacial refugia meet. The study included 33 silver fir populations from Ukraine, Romania and Slovakia which were investigated using the maternally inherited mitochondrial nad5-4 marker and biparentally inherited nuclear microsatellites. The boundary between mitochondrial lineages is very sharp; only six populations containing a mixture of different haplotypes were found. Bayesian analysis of population structure based on seven nSSR loci revealed the existence of two clusters which coincided fairly well with mitochondrial lineages. Both haplotype frequencies and proportions of clusters identified by the Bayesian analysis exhibited a clinal transition over the contact zone, with cline widths of 17.6 km for mitochondrial haplotype frequencies (reflecting gene flow by seeds) and 119.6 km for Bayesian clusters based on nSSR (reflecting gene flow by pollen). Allelic richness and gene diversity differ significantly between mitochondrial lineages, the Balkan group being more variable, but an increase in gene diversity towards the boundary between lineages was observed only within the Balkan lineage. The observed patterns are suggested to reflect the postglacial colonization and historical gene flow. They demonstrated that in silver fir as a wind-dispersed species, the colonization front is quite continuous, and the survival of migrant seeds in already established populations is low. The relative contribution of pollen-mediated gene flow to genetic exchange between divergent lineages associated with glacial refugia is much higher than in the case of seeds, but pollen dispersal distance is lower than suggested by earlier studies.

Responses of Norway spruce populations to climatic transfer, in terms of growth and survival, were analyzed on the basis of a provenance experiment derived from the international provenance test IUFRO 1964/1968. The experiment comprises a series of five trial plots situated at contrasting elevations ranging from 484 to 1,275 m a.s.l., with 11 provenances represented at all trial plots that were used for the analysis. Transfer rates were defined as differences in altitudes or climatic variables between the site of plantation and the site of origin. Optimal transfer rates and optimal climates for individual provenances were derived from quadratic response functions. Spruce provenances generally responded positively by height and volume growth to transfer into lower altitudes, i.e., warmer conditions with less precipitations. The analysis at the level of provenances showed that optimal transfer rates were consistently negatively correlated with the underlying environmental variables and optimal climates were consequently nearly the same for all provenances irrespective of the response traits and ecodistance variables. Stability indices based on joint regression analysis indicate that provenances from higher altitudes, colder and wetter climates tend to be more stable, whereas provenances from lower altitudes, drier and warmer sites are more responsive to site quality. However, the differences in the stability are small and stability indices were generally close to 1. The results indicate that populations in different climates remain adapted to a common optimum and the extent of local adaptation is quite limited. Possible explanations of this observation are briefly discussed.

The genetic variation in fourteen Sorbus torminalis (L.) Crantz. populations distributed over the eastern and south-eastern part of its range was studied using seven nuclear microsatellite loci. The differentiation level was relatively high (FST = 0.228), as expected for a species with a fragmented range. The distance-based approach to the analysis of differentiation patterns (neighbour-joining tree based on pairwise coefficients of differentiation) did not reveal a clear geographical structure. On the other hand, model-based Bayesian methods (BAPS and STRUCTURE) gave geographically continuous clusters of populations. The occurrence of populations deviating strongly from the general pattern is attributed to founder effect. In spite of a generally high differentiation, a significant isolation-by-distance pattern was found, which might be a consequence of postglacial migration and gene flow among descendants of different refugia.

Reticulate evolution resulting from gene flow among diverged taxa was studied on the example of the Fagus sylvatica species complex in Europe and western Asia. F. sylvatica L. is one of the most widespread woody species of the Northern Hemisphere with two commonly recognized subspecies (namely, F. sylvatica subsp. sylvatica and F. sylvatica subsp. orientalis) and two putatively hybridogenous or intermediate taxa (F. moesiaca and F. taurica). Whereas the distribution of F. sylvatica subsp. sylvatica in Europe is almost continuous, the Asian range of F. sylvatica subsp. orientalis is fragmented into several larger regional populations. We studied genetic variation at 12 allozyme loci in 279 local subpopulations to assess whether previous contacts of regional populations left traces in their gene pools. Two approaches were used to infer potential reticulations: the reticulate network (Makarenkov and Legendre in J Comp Biol 11:195–212, 2004) and the neighbor-net network (Bryant and Moulton in Mol Biol Evol 21:255–265, 2004). A UPGMA dendrogram based on genetic distances between local populations revealed a high differentiation level within subsp. orientalis, whereby populations from Asia Minor, the Caucasus and the Alborz mts. were placed in different clusters. The reticulated network showed possible connections among adjacent populations, putatively resulting from previous contacts. The neighbor-net network also consisted of two major groups corresponding to F. sylvatica s. str. + F. moesiaca and F. orientalis including F. taurica. Regional populations of F. moesiaca are placed close to the basis of the European branch and are highly networked, indicating ambiguity in the phylogenetic signal. Similarly, three subgroups can be distinguished within the F. orientalis group and correspond well with broad regions of Asia Minor, the Caucasus and the Alborz. The Amanus regional population is intermediary between the subgroup of Asia Minor and the Caucasian subgroup. Crimean populations (i.e., putative hybrids) are placed near the basis of the subgraph. Two explanations of the observed reticulations are discussed: expansions and retreats of the range of beech associated with Pliocene and Pleistocene climatic fluctuations, resulting in contacts and exchanges of gene pools among regional populations, and sharing ancestral polymorphisms due to incomplete lineage sorting.

The study focuses on geographical patterns of genetic variation at allozyme loci common for four main tree species of Central Europe (Norway spruce, silver fir, common beech and sessile oak). Moving-window averaging of four indicators of allelic richness and diversity (proportion of polymorphic loci, mean number of alleles per locus, effective number of alleles and expected heterozygosity) with window size of 50 × 50 km was used to identify the patterns. Moreover, local genetic divergence was assessed using the G ST (Nei, Molecular population genetic and evolution, Amsterdam and Oxford, North-Holland, 1975) and D j (Gregorius and Roberds, Theor Appl Genet 71:826–834, 1986) statistics for common beech and silver fir, where raw genotype data were available. Spatial patterns of diversity and allelic richness were quite similar. Romanian Carpathians were identified as the most important hotspot of genetic diversity and evolutionary divergence in Central Europe. Implications for genetic conservation are briefly discussed.

The impact of secondary succession of grassland communities towards a Norway spruce forest on soil microbial community was studied on a belt transect established in the Pol’ana Mts., Central Europe. Data on understory vegetation, light availability, soil properties and microbial activity were collected on 147 plots distributed over regular grid. Moreover, distributions of functional groups of microorganisms were assessed using BIOLOG analysis on a subset of 27 plots. Mantel partial correlations between microbial community indicators and environmental variables showed that microbial activity generally decreased with increasing tree density and size, whereas it increased with increasing radiation at the soil surface, soil temperature, and cover and diversity of understory vegetation. Functional richness and diversity of microorganisms were positively correlated with solar radiation, but also with plant species richness and diversity. Abundance of several functional groups correlated closely with succession-related variables. Redundance analysis of microbial data provided slightly different outcomes. Forward selection yielded only two environmental variables significantly influencing the composition of the microbial community: tree influence potential and organic carbon content. Abundances of several functional microbial groups correlated with tree influence, documenting that microbial community changes are at least partially driven by the colonization of grassland by trees. Nevertheless, the relative importance of abiotic environment change and plant community succession on microbial community dynamics remains unresolved.

This study analysed seasonal dynamics of macrophyte abundance in two perennial lowland regulated streams (Stream 1 and 2) in the Danube basin (Slovakia). Assessments of macrophyte abundance and environmental characteristics were accomplished 7 times during the vegetation period in 2005 within a 100 m long section. Statistically significant differences in total abundance of macrophytes as well as an abundance of macrophyte groups (hydrophytes, amphiphytes, helophytes) and Potamogeton nodosus were detected among months within the vegetation period. Abundance fluctuations for individual macrophyte groups and species were moderate in Stream 1 and much stronger in Stream 2. Only amphiphytes showed bimodal temporal distribution in Stream 1, but the abundance of this group was low, reflecting more or less random occurrence of species in vegetation period. Multiple linear regression revealed that water depths and air temperature are the most significant environmental variables affecting the seasonal pattern of total as well as dominating group abundance in Stream 1 and 2, respectively. In all cases, abundances are significantly influenced by the abundance of the respective group in the preceding month. Culmination time differed between streams for all macrophyte groups except helophytes. Total abundance culminated 0.57 month later in the Stream 1 compared to Stream 2.

To induce somatic embryogenesis of Greek fir, Abies cephalonica Loud., the influence of different cultivation media, sampling dates, and cold treatment storage were examined. The initiation frequencies ranged from 1% to 25%. The sampling date had a significant effect on the initiation of embryogenic cultures and a high frequency was observed within a 5 week window. The effect of cone storage, composition of initiation media, and the medium by storage interaction also remained nonsignificant after 3 and 10 months of proliferation growth. At the maturation phase, the highest tested concentrations of abscisic acid (ABA), 16 and 32 µmol/L, increased both the capability of embryogenic cell masses (ECMs) to produce embryos and the mean number of embryos. Of the two tested carbohydrates, maltose-containing media produced more embryos altogether (1943, on the average of 22.3 embryos per gram fresh mass) and 76% of the ECMs were able to produce embryos when compared with the corresponding values (152, on the average 3.0 embryos per gram fresh mass) and 15.3%, respectively, on sucrose-containing medium. However, 93.5% of embryos on maltose-containing medium died during the germination phase, whereas the corresponding percentage on sucrose-containing medium was 78.2%.

Comparative study on fertilization process in Pinus sylvestris, Pinus mugo and in their putative hybrid swarm individuals was done involving pre-zygotic and post-zygotic stages. The amount of surviving ovules from open pollination reflecting the mode of interaction between pollen grains and nucellar tissue of an ovule averaged at 8.1 of sound ovules per conelet in Pinus sylvestris, 7.3 ovules in the hybrid swarm population and at 4.9 ovules in Pinus mugo. A strong correlation was observed between the number of surviving ovules and the proportion of germinating seeds in the compared species and hybrids. Normal course of embryogenesis in Pinus sylvestris and Pinus mugo contrasted with increased frequency of disturbances observed in the hybrid swarm individuals. The differential survival rates of the ovules and deviations from typical pattern of embryogenesis are discussed from the standpoint of cross-ability relationship between Pinus sylvestris and Pinus mugo.

Summary 1. Growth rates of European silver fi r( Abies alba Mill.) rapidly increased in the last century. At the same time, ring widths declined at the species southern distribution limits in the Mediterranean. Such diverse growth trends and responses have largely been attributed to regional climate conditions, but this was prior to considering the species’ post-glacial phylogeny. 2. A dendrochronological network composed of 1961 tree-ring width series (TRW) from 78 silver fir sites between 365 and 1400 m a.s.l. along the Carpathian Arc was compiled. Spatial differences in the species’ genetic diversity were investigated from genetic data of 69 silver fir populations in the region. Differences in growth variability and climate sensitivity were then related to post-glacial phylogeny and genetic diversity. 3. Significant differences in interannual and longer-term growth trends and climate responses across the Carpathian Arc were found to coincide with the geographical north–south separation of two post-glacial populations from effective refugia originating from the Apennine and Balkan peninsulas. Summer temperature was the main driver of growth in the western (Apennine) lineage, whereas ring widths in the Balkan population from the east were predominantly controlled by summer drought. Fir specimens that originated from the Balkan lineage exhibited higher genetic diversity and more regular growth dynamics and also appeared to be less sensitive to air pollution during the 1970s. 4. Synthesis. Although the phylogeny of forest trees has largely been neglected in most dendroecological studies, results here indicate the importance of different post-glacial histories for the growth sensitivity and adaptability to varying environmental factors. Decision-making under future climate warming scenarios (for building resilience through forest management) should therefore consider different phylogenetic origins.

Fagus sylvatica L. is one of the most widespread broad-leaved trees in the temperate forests of the northern hemisphere. In addition to two subspecies, F. sylvatica ssp. sylvatica in Europe and F. sylvatica ssp. orientalis in south-western Asia, two further taxa were described: F. moesiaca (Maly) Czeczott in the south-western Balkans and F. taurica Popl. in Crimea. The opinions about the number and ranks of taxa within this complex are highly controversial. To assess the degree of genetic differentiation among them, and to reveal geographical patterns of genetic diversity and their relationships to history and biogeography of beech populations, genetic variation at 12 allozyme loci was studied in 279 populations in western Eurasia. A Bayesian analysis of population structure revealed the existence of two clusters, which fairly well coincided with F. sylvatica ssp. sylvatica and F. sylvatica ssp. orientalis, whereby the populations from the south-western Balkans and Crimea contained a mixture of these two gene pools. On the other hand, a neighbour-joining tree based on pairwise FST failed to separate the subspecies into well-defined distinct clades. Populations of F. sylvatica ssp. orientalis proved to be incomparably more differentiated than ssp. sylvatica (FST = 0.157 and 0.032, respectively). Asian populations also showed higher levels of allelic richness both on population and taxon levels than the European ones (the number of alleles after rarefaction was 3.40 and 4.27 in F. sylvatica ssp. sylvatica and ssp. orientalis, respectively). This indicates that the gene pool of F. sylvatica ssp. orientalis has not been depleted by reduced population sizes during the Pleistocene glaciations, as is the case of F. sylvatica ssp. sylvatica. Genetic similarities between isolated regional populations are explained by shared ancestral polymorphisms and/or range overlaps with subsequent hybridization in the past. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 154, 165–174.

Although changes in land-use, climate, and the spread of introduced tree species have increased the global importance of tree invasions into grasslands, our ability to predict any particular invasion is limited. To elucidate mechanisms driving tree invasions of grasslands, we studied in detail how seed dispersal and fine-scale environment control the expansion of an introduced Picea abies Karst. (Norway spruce) population into Western Carpathian grassland. We mapped invading trees and measured tree size, fecundity, seed rain, seedling density, plant community composition, and light and soil environment within a 200 × 60 m belt across the invasion front. Maximum likelihood estimates of dispersal kernels suggested peak seed deposition directly underneath tree crowns where germination was poor, but mean dispersal distances were sufficiently large to generate overlapping seed shadows from multiple trees that saturated the invasion front with seeds further away from seed-dispersing trees. Partial Mantel tests indicated that germinant density was affected considerably less by seed rain than by moss cover (r = 0.54), overstory tree influence (r = −0.32), soil moisture (r = 0.21), grass cover (r = −0.15), and diffuse radiation (r = 0.13). However, these variables were not independent but formed complex multivariate gradients within the invasion front. Moss cover and soil moisture were negatively correlated with overstory tree influence and the resulting gradient clearly affected germinant density (partial Mantel r = 0.45). In contrast, positively correlated light and grass cover defined a gradient related weakly to germinant density (partial Mantel r = 0.05) as it integrated opposing effects of these variables on germinants. Seedlings had similar environmental associations, but except for the lasting positive effects of moss these tended to weaken with seedling size. Although a few seedlings may establish and survive in the more adverse environment of the outer edges of the invasion front, a significant population expansion may require a gradual build-up of the critical density of invading trees to reduce grass cover and facilitate germination on moist mossy seedbeds within uncolonized areas. Thus, Picea abies appears more likely to spread within temperate grasslands by gradual expansion of its population frontier rather than by advanced groups.

The effects of air pollution on the genetic structure of Norway spruce, European silver fir and European beech were studied at four polluted sites in Slovakia, Romania and Czech Republic. In order to reduce potential effects of site heterogeneity on the health condition, pair-wise sampling of pollution-tolerant and sensitive trees was applied. Genotypes of sampled trees were determined at 21 isozyme gene loci of spruce, 18 loci of fir and 15 loci of beech. In comparison with Norway spruce, fewer genetic differences were revealed in beech and almost no differentiation between pollution-tolerant and sensitive trees was observed in fir. In adult stands of Norway spruce, sensitive trees exhibited higher genetic multiplicity and diversity. The decline of pollution-sensitive trees may result thus in a gradual genetic depletion of pollution-exposed populations of Norway spruce through the loss of less frequent alleles with potential adaptive significance to altered stressing regimes in the future. Comparison of the subsets of sensitive and tolerant Norway spruce individuals as determined by presence or absence of discolorations ("spruce yellowing") revealed different heterozygosity at 3 out of 11 polymorphic loci.

Three Alnus glutinosa populations from central Slovakia were investigated by means of isozyme analysis. The average expected heterozygosity ranged from 0.151 to 0.173. Despite significant differences in allele frequencies among populations, genetic differentiation was low (FST=0.022). Intrapopulation fixation indices indicate no or very slight deviation from panmictic expectations towards the heterozygote deficiency. No indications were found that the investigated populations have experienced recent bottlenecks in population size. A spatial autocorrelation analysis based on Moran’s I indicates the existence of a spatial genetic structuring in the population Kral’ova. Patch size was estimated to be 70–100 m, which is more than observed in other broadleaved tree species. This difference is explained by the linear shape of alder populations and a higher mobility of seeds.

A total of 1113 oak trees from 222 populations originating from eight countries (Austria, Bosnia-Herzegovina, Croatia, Hungary, Romania, Slovakia, Slovenia, Yugoslavia) were sampled in natural populations or in provenance tests. The sampled trees belong to four different species (Quercus robur, Quercus petraea, Quercus pubescens, Quercus frainetto) and to several putative subspecies. Variation at four chloroplast DNA (cpDNA) fragments was studied using restriction enzymes, resulting in the detection of 12 haplotypes. One haplotype was present in 36% of the trees, and six were found in 6–17% of the trees. The haplotypes are shared extensively between species and subspecies. They belong to three different lineages (A, C and E) and are phylogeographically structured in the region investigated. Haplotypes of lineage E dominate to the east of the Carpathian mountains in Romania, whereas the Carpathian Basin seems to have been colonised along several different colonisation routes, from the Balkan peninsula but also from Italy. The data support the possible role of climatic instability during the late glacial period in shaping this complex geographic structure. The presence of several secondary refugia could be inferred in the region, which have played a major role in the second step of recolonisation, at the onset of the Holocene period. # 2002 Elsevier Science B.V. All rights reserved.

International audience; At northern temperate latitudes trees haveadjusted their ranges substantially in response to changingclimates during the Holocene. Results from dispersalmodel simulations suggest that postglacial migration ratesmay have been over-estimated from fossil pollen data. As acontribution to this debate, we infer the migration rates ofAbies alba(Mill.), silver fir, as a case-study species, byusing a spatially explicit approach based on fossil pollenbut taking into account its modern genetic diversity pattern. Maximum estimates of migration rates from fossil pollendata alone are higher than 700 m yr-1during the Holocene.Considering the potential refugia as suggested from all thefossil data but restricting the area over which silver firexpanded from each glacial refugium using data on thecurrent haplotype distribution, the estimated maximummigration rates of silver fir are less than 250 m yr-1.Genetic information may allow for (1) the exclusion of thoserefugial areas where the species may have survived duringthe last glacial period but from which it did not spread orspread only very locally and (2) the delineation of the areas. over which the species spread from each glacial refugium.The estimated rates in the present study are generally con-sistent with rates suggested from modelling approaches.This study shows that integrating fossil pollen records canimprove simulations of dispersal processes and, thus, allowfor better predictions of future changes in tree species’ranges.

The effects of industrial pollution on allelic and genotypic structures of Norway spruce, European silver fir and European beech were investigated by means of isozyme analysis. In a mixed Norway spruce–silver fir forest stand in an area heavily polluted by sulphur dioxide and heavy metals in the region of Spis (eastern Slovakia), pairs of neighbouring damaged and apparently healthy trees were selected in two replicates (44 and 69 pairs in a heavily and moderately damaged stand, respectively). Pairwise sampling of trees with contrasting vitality was applied to reduce potential effects of site heterogeneity on the vitality of sampled trees. No significant differences in allelic and genotypic frequencies were found between sets of healthy and declining trees. There were differences in the single-locus heterozygosities, but these were not consistent between the replicates. However, the set of damaged trees exhibited higher levels of genetic multiplicity and diversity, possibly due to the deleterious effect of rare alleles under the conditions of air pollution. Consequently, following the decline of pollutant-sensitive trees, the remaining stand will be depleted of a part of alleles with unknown adaptive value to future selection pressures.

Seed zones for European beech (Fagus sylvatica L.) in the Czech Republic were proposed on the basis of isozyme polymorphism. Twenty beech populations distributed over the natural range of beech in the target area were analyzed using 12 isozyme loci. Analysis of genetic distances revealed the existence of geographical differentiation patterns. Allelic fre- quencies were estimated for a square network of 300 points, covering the territory of the Czech Republic, employing kriging as an optimum spatial interpolation method. Cluster analysis based on allelic profiles of the kriging points made it possible to divide the investigated area into eight seed zones. (© Inra/Elsevier, Paris.)

Xylem cavitation resistance is a key physiological trait correlated with species tolerance to extreme drought stresses. Little is known about the genetic variability and phenotypic plasticity of this trait in natural tree populations. Here we measured the cavitation resistance of 17 Fagus sylvatica populations representative of the full range of the species in Europe. The trees were grown in three field trials under contrasting climatic conditions. Our findings suggest that the genotypic variability of cavitation resistance is high between genotypes of a given population. By contrast, no significant differences were found for this trait across populations, the mean population cavitation resistance being remarkably constant in each trial. We found a significant site effect and a significant site×population interaction, suggesting that cavitation resistance has a high phenotypic plasticity and that this plasticity is under genetic control. The implications of our findings for beech forest management in a context of climate change are discussed. © The Author 2011.

The annual development cycle of boreal and temperate trees results from an evolutionary trade-off between two opposing forces. These are namely, the adjustment of leaf phenology to the timing of frost occurrence at the beginning and/or the end of the growth season countered by an effective adjustment to the duration of the growth season to maximise photosynthesis and biomass production during the growing season. In a provenance trial of common beech (Fagus sylvatica L.) populations, we tested whether avoiding frost events by late flushing is the primary process of frost tolerance, and also, whether longer growth seasons resulted in an increase in biomass production. We detected clines with altitude and longitude of provenances for phenological traits, in contrast to growth variables. A highly significant negative genetic correlation was detected between frost damage and budburst date which confirms that the timing of leaf flushing is the principal determinant of tolerance to late frost. Height and diameter growth were positively correlated with the length of the vegetation season. However, this effect was associated with the timing of growth cessation rather than with budburst. Stabilizing selection, selective pressure on early leaf flushing of juveniles in dense natural beech stands, and epigenetic regulation of budburst are proposed as explanations for these observations.

This study focused on the responses of soil microorganisms to different management regimes on disturbed windthrow areas. Microbial parameters potentially serving as indicators of environmental changes within a long-term monitoring of forest development after large-scale disturbance events were assessed. Basal and substrate-induced respiration, N mineralisation, catalase activity, microbial biomass as well as functional diversity based on Biolog assay were determined in soil samples from three disturbed plots and an undisturbed reference plot in the Tatra National Park (Slovakia) since 2006. A relative congruence of inter-annual trends of microbial activity indicators at all plots results from a common response of microbiota to changes of climate at the landscape level after forest stands were destroyed. While catalase activity and functional diversity proved to be useful indicators of temporal trends, microbial biomass seems to reflect different management regimes at the disturbed plots.

Isozyme analysis was applied to determine the genetic structure of 14 Norway spruce populations from Slovakia. Gene diversity as well as observed heterozygosity proved to be comparatively high. No essential differences were found between virgin forests and naturally regenerated stands. On the other hand, the genetic variation in artificially established stands proved generally to be decreased. The changed genetic structure is reflected also by large values of genetic distances of these stands from all remaining populations as well as from each other.

Disturbance events may be human-induced or natural, both typically causing changes in ecosystem properties and functions (Wright and Coleman 2002). Many observations show an increasing frequency of risks related to natural hazards in most parts of Europe. Natural hazards (flood, drought, erosion, fire, storm damage, etc.), driven by weather extremes, are increasing as a consequence of climate change (Thurig et al. 2005, Anonymous 2007).

International audience; We present a range-wide synthesis of our own research and related work on the complex postglacial history of Abies alba Mill. It is based on macroremains, fossil pollen records as well as on different genetic markers. The geographic distribution of genetic lineages and allele frequencies together with the fossil records confirm multiple refugia with at least three of them being sources for the Holocene range expansion into Central Europe, representing so-called effective refugia. One is located in the northern Apennines. A long-term refugium in the southern Balkans contributes to northward expansion with a branch along the Carpathians in the East and the Dinaric Alps in the West. Furthermore, new allozyme data indicate a third effective refugium in the northern or western Balkans, respectively. Using different genetic marker categories the differentiation of A. alba populations could be attributed to different time scales. A separation of maternal lineages took place in previous glacial cycles of the Quaternary, while a second pattern of genetic differentiation is the result of isolation processes during the last glaciation and subsequent gene flow after range expansion. Suture and introgression zones of refugial gene pools were clearly recognised. The patterns of genetic variation and genetic diversity spanning between rear and leading edges of the present range are discussed for evolutionary implications and conservation strategies.

International audience; Here, palaeobotanical and genetic data for common beech (Fagus sylvatica) in Europe are used to evaluate the genetic consequences of long-term survival in refuge areas and postglacial spread. Four large datasets are presented, including over 400 fossil-pollen sites, 80 plant-macrofossil sites, and 450 and 600 modern beech populations for chloroplast and nuclear markers, respectively. The largely complementary palaeobotanical and genetic data indicate that: (i) beech survived the last glacial period in multiple refuge areas; (ii) the central European refugia were separated from the Mediterranean refugia; (iii) the Mediterranean refuges did not contribute to the colonization of central and northern Europe; (iv) some populations expanded considerably during the postglacial period, while others experienced only a limited expansion; (v) the mountain chains were not geographical barriers for beech but rather facilitated its diffusion; and (vi) the modern genetic diversity was shaped over multiple glacial-interglacial cycles. This scenario differs from many recent treatments of tree phylogeography in Europe that largely focus on the last ice age and the postglacial period to interpret genetic structure and argue that the southern peninsulas (Iberian, Italian and Balkan) were the main source areas for trees in central and northern Europe

Spatial distribution and genetic variation of a population of Sorbus chamaemespilus (L.) Crantz and putative hybrids between S. chamaemespilus, S. aria and S. aucuparia growing in the nature reserve Skalnä Alpa (central Slovakia) were studied. The analysis of spatial patterns using Ripley's K-function revealed a significant clustering of the adults of both S. chamaemespilus and hybrid taxa at distances up to ~15 m and a strong affinity between both taxonomical groups, indicating similar ecological requirements. Bivariate point-pattern analysis considering cardinal direction showed that juvenile individuals of S. chamaemespilus are clustered around the adults up to the distance of ~2 m, whereas in hybrid taxa with larger and more dense crowns, juveniles are clustered at distances more than ~3 m from the adults. The analysis of genetic variation in a subset of adult shrubs using 4 nuclear microsatellite loci revealed that unlike expected, there was no variation in S. chamaemespilus but several genotypes were found in the group of hybrid taxa. Implications for the reproduction system and conservation of the investigated taxa are discussed.