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The research was conducted on explants of silver fir (Abies alba Mill.) deriving from several forest districts in southern Poland. The study encompassed the influence of the origin of plant material, type of explants, kind of substances used for explants sterilization, PPM and the type of medium on the ability to form embryogenic callus and to develop somatic embryos in silver fir explants. From the plant material collected in three sites, 57 clones were obtained from mature zygotic embryos; this produced an embryogenesis frequency of 6%. Embryogenic callus was obtained with a diameter of 65–70 mm depending on the material origin. The best medium for development of callus inducted on embryos isolated from mature silver fir seeds was the SH medium. Somatic embryos were formed in a globular stadium (24 pieces) on this medium. The 10% solution of NaOCl (used for 15 minutes) turned out to be the most effective substance for seed sterilization.
Thirty silver fir populations originating from the putative suture zones of the postglacial recolonization (Slovenia, Bosnia and Hercegovina, Ukraine) were studied using a mitochondrial nad5-4 gene marker. The geographical distribution of mtDNA haplotypes in the Ukrainian Carpathians and their northern foothills indicates a very recent meeting of migration streams arriving from the Romanian Carpathians and Central Europe. In the western part of the Balkan Peninsula, two counterparallel migration streams are the most plausible explanation of the pattern observed. The haplotype typical for the Balkan Peninsula predominates along the Adrian coast, whereas the CentralEuropean haplotype is more represented in the inland.
Knowledge of the vegetation and the monitoring of its changes in preserved areas is an essential part of effective conservation policy and management. The aim of this study was to assess the effectiveness of traditional methods of conservation of silver fir forests. The study analyses the changes in the structure and species composition of a temperate forest excluded from the commercial silvicultural management for 50 years, and since then protected as a nature reserve. The study is based on a comparative analysis of phytosociological reléves made on permanent plots in 1961, 1982, 1994 and 2011. PCA and ecological indicator values were analyzed, as well as characteristic species based on an indicator value (IndVal) index. Results revealed significant and dynamic changes in the forest structure and composition. The mixed coniferous-broadleaved forest with Abies alba and diverse ground flora, considered in the 1960s as valuable and worthy of conservation, was found to have been anthropogenically transformed and unstable. Significant reduction in the human impact was followed by spontaneous regeneration of oak–hornbeam forest. However, the directional process of changes in vegetation was modified by such silvicultural treatments as selective cutting of trees and gap creation, all intended for silver fir maintenance. The results show that Carpinus betulus effectively outcompeted Pinus sylvestris, Picea abies, Quercus robur and A. alba. Changes in the forest overstory and understory caused temporal changes in the habitat conditions reflected in changes in the ground vegetation composition. The proportion of light-demanding and oligotrophic species significantly decreased, while the contribution of species with a wide ecological amplitude, i.e. more shade-tolerant and nutrient-demanding – increased. The share of A. alba was reduced. Species defined in this study as most valuable, should be actively protected, or selection of conservation targets should be re-evaluated.
The research was conducted with a view to establishing physiological parameters of the silver fir (Abies alba Mill.) with regard to germination energy, absolute germination and genetic overload produced by silver fir populations. The intention was to identify significant variability within populations and subpopulations, or rather within the two combined, and to give recommendations on the usage and usability of seeds from specific populations. The results form a basis for establishing silver fir genetic overload within five fir populations of central Bosnia and Herzegovina. The results of research on the characteristics such as absolute seed weight, germination energy and absolute germination are within a scope of previous studies. The studied physiological characteristics of silver fir seeds in the central Bosnia area showed distinct individual and inter-population variability when compared to variability of the subpopulations analyzed. The inclusion of non-physiological data (height, DBH, age and the presence of mistletoe) concerning sampled trees proved to be effective new quality of research. No correlation was found between DBH and seed physiological characteristics but increased tree height had a positive effect on seed quality in terms of absolute germination and growth, proportional to tree height. This in turn shows that seeds should be collected only from trees of above average height, because they are less genetically overloaded. The characteristics of healthy but ungerminated seeds from less tall trees displayed lower parameter values, also indicating that seeds should be collected from taller than average trees only. The presence of mistletoe had a very interesting effect of increasing rotten seeds percentage, and therefore reducing seed quality. Accordingly, seed collection should be limited to trees not affected by mistletoe, however further research on this aspect is required.
The study presents the structure and floristic composition of mixed fir forest at the northern range limit of European silver fir (Abies alba) in Poland. Phytosociological data were collected in the forest reserve “Murowaniec”,which was established to protect mixed forest ecosystems with a large contribution of fir trees. Changes in floristic composition of these coniferous forests in the last 40 years were discussed. Protective measures are suggested in this paper, aiming at conservation of the forest ecosystems of the reserve.
The available phytosociological literature were reviewed and compared with 12 original relevés made on representative of habitats of fir trees in the study area. Only in the eastern part of the Sudety Mts. silver-fir is still important forest tree. It is found most frequently in potential sites of acidophilic beech forest, which vegetation is now strongly transformed because of planting them with spruce. Typical, mainly acidophilic beech forest takes second place (in respect of frequent occurrence). Oak-hornbeam forest take third position.
In the 40 fir localities in the Sudety Mountains, varying in site conditions and the degree of natural regeneration development were taken soil samples from the mineral horizon and were subjected to particle size distribution analysis. The best regeneration of fir stands has been reported on medium-textured soils, containing a few percents of the clay fraction and from 50to 60% of sand.The poorest regeneration was reported on silty soils, located in the lower parts of slopes. In comparision with the Carpathians, spectrum of conditions in which firs grow in the Sudety Mountains is clearly shifted from coarse-textured soils to medium-textured soils.
In this paper, is presented data on the abundance and age structure of natural regeneration of silver fir in permanent plots in Sudety Mts. In the studied plots the abundance of fir seedlings is usually markedly lower than in the well-regenerating Carpathian forest stands. The major reason for this is the lower contribution of fir trees to forest stands in the Sudety Mts. as compared with the Carpathians. In most plots the process of regeneration is long and extended over many years. Largest numbers of seedlings developed in years of good fir cone crops. An important role in the process of natural regeneration of Abies alba in the Sudety Mts. are played by type of site, kind of humus and herb layer density. Most of the studied forest stands in the Sudety are not dense, so the herb layer is well-developed, that strongly restrain fir regeneration especially in fartile soils.
Seeds collected from individual trees in the 16 Carpathian and 2 Sudeten silver-fir (Abies alba) populations were studied with the starch gel electrophoresis in megagametophytes using 14 enzyme systems with 28 loci. The results show that the geographical distance between populations are in a small part reflected in genetic distances. There are two main groups of populations: Sudeten and Carpathian with a very big genetic distance between them. Other populations consist of a few small groups with low gene flow between them (Nm = 3.286). About 80% of genetic variation is located within populations (FST = 0.223). Average values for genetic multiplicity and diversity for Carpathian populations are as follows: number of alleles per locus: Na = 2.308, with effective number of alleles Ne = 1.552 and proportion of polymorphic loci 71.21%. The mean number of alleles per locus (Na) varied from 2.107 to 2.607 in population. The mean effective number of alleles per locus (Ne) ranged from 1.429 to 1.662. Average Fis for Carpathian populations was -0.021, which means that there is small excess of heterozygotes. The average observed heterozygosity amounted to Ho = 0.275 and expected heterozygosity was He = 0.269. The dendrogram structure and presence of rare alleles found in silver-fir of Czech, and Slovakian populations allow for a hypothesis that in postglaciation the silver-fir moved into the Polish Carpathians not westward from the east but from the south along river valleys from some Balkan refuges, getting North bypassing the High Tatra Range. This way, a highly diversified set of populations originated, differ in the presence of rare alleles. This differentiation is not prevented by a relatively small flow of genes between populations. The calculated gene flow Nm = 3.286 also indicates isolation between the populations. It means 3.3 immigrants per generation into the studied populations.
Morphological and anatomical traits of needles of Abies alba saplings growing under the canopies of Picea abies, Fagus sylvatica, Betula pendula, Pinus sylvestris and Larix decidua were studied. An acclimation of the needles to different light conditions created by the principal species of the canopy was assessed using different microscopic methods. Length, width, needle area, stomatal density, parenchyma thickness, resin ducts diameter, central cylinder size and other traits of needles allowed to determine their structural plasticity in response to irradiance level. Leaf mass to area ratio, palisade parenchyma thickness, diameter of resin ducts increased, whereas width/thickness ratio and needle thickness/parenchyma thickness ratio decreased with increasing canopy openness. Variation in the investigated patterns of the needles reflected their structural plasticity and also an ability of silver fir saplings to acclimate to irradiance under the canopies of diverse tree species.
Progeny of four adult silver firs, which were an admixture in Norway spruce (Picea abies) stand was, analyzed. The study was done in lower mountain zone of the Karkonosze (Giant Mts.) National Park (SW Poland). The seedlings occurred in two clumps related to the position of adult trees, whereas spatial pattern of the seedlings inside each clump was random. The seedlings were spaced mainly in distances 5–25 from the nearest adult tree. The maximal distance was up to 50 m. Most seedlings were established in accordance with main wind directions. Also, in these directions seedlings were more distant from adult trees than in other directions. The seedlings grew in better light environment (12% of PPFD) than average (9,6% PPFD). This effect was statistically significant. The height increment of the seedlings was low and was not correlated with light conditions. Similarly, there was not any correlation between the apical dominance ratio and light. The lack of this correspondence we attributed to browsing. The silver fir seedlings were significantly underrepresented in patches of Vaccinium myrtillus, on raw needles, under crown of adult trees and in concave micro-relief form. The underrepresentation in the places covered by canopy and in patches of bilberry we related to the indirect effect of continuous browsing, which leads to higher seedlings mortality in more shaded places and sites of stronger competition between forest floor vegetation and silver fir seedlings.
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