The Community of Fine Root Fungi of Silver Fir (Abies alba Mill.) Saplings

This study aimed to assess the biodiversity of fungi colonizing the fine roots (diameter up to 2 mm) of 3-year-old silver fir saplings from areas of Międzylesie Forest District in Poland. It was hypothesized that quantitatively and qualitatively, mycorrhizal fungi would be the dominant fungi in root communities of silver fir. DNA extraction was performed using Plant Genomic DNA purification. The internal transcribed spacer1 (ITS1) rDNA region was amplified using specific primers, and the amplicons were purified and sequenced using sequencing by synthesis (SBS) Illumina technology. The obtained sequences were compared with reference sequences in the UNITE database (https://unite.ut.ee/) using the basic local alignment search tool (BLAST) algorithm to facilitate species identification. A total of 307,511 OTUs was obtained from each sample. There were 246,477 OTUs (80.15%) of fungi known from cultures. The genera Tuber spp. (7.51%) and Acephala spp. (3.23%) accounted for the largest share of the fungal communities on the fine roots of fir trees. Hence our results indicate the dominance of mycorrhizal fungi in these communities and reflect the excellent quality of the saplings that were assessed. Pathogenic fungi constituted a much smaller share of the fungal communities

Wzrost i rozwój szczepów jodły pospolitej (Abies alba Mill.) na plantacji zachowawczej w Nadleśnictwie Śnieżka =The growth and development of silver fir (Abies alba Mill.) grafts in the seed orchard in the Śnieżka Forest Districts

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Comparing Scots pine regeneration established by sowing and planting at various times of year

The aim of this study was to evaluate the practical feasibility of two forest regeneration methods using Scots pine Pinus sylvestris L. To this end, comparative experiments were established in the Złotoryja and Legnica Forest Districts. The site in Złotoryja had been clear cut, while the experimental plot in Legnica was established at a location damaged by wind in 2009 and cleared from wind throws and wind-broken trees before the experiment. Four different dates for sowing and two for planting were chosen in order to investigate the potential forest regeneration with respect to time. Both experiments were established according to the same design: a complete random block design with five replication blocks. To each plot we applied approximately 53 g (1.2 kg/ha) of seeds and planted 230 seedlings (10 200 seedlings/ha). In 2017, the height of the pine trees was recorded and their increment in height was measured in 2016 as well as 2017. A preliminary analysis of results was conducted using ANOVA for multiple experiments in order to identify significant differences and to then combine variables to form homogeneous groups to which the Duncan multiple range test could be applied. For growth traits, the ANOVA showed significant differences between experimental sights as well as a significant interaction of factors with the experimental site. In terms of planting, April was the most advantageous resulting in the greatest tree height in both forest districts, while in the Legnica Forest District the saplings planted in April also showed the greatest annual increments. Among the sowing dates, the most advantageous was the winter sowing, while the April sowing date produced the least desirable results. In conclusion, both sowing and planting are effective methods to establish pine cultures in coniferous forest

Wood density in European larch (Larix decidua Mill.) from selected provenances grown at the Siemianice Forest Experimental Station

The purpose of this study was to determine variation in the density of wood from different provenances, growing under the same soil and climate conditions. Samples were obtained from an experimental site located at the Siemianice Forest Experimental Station. We analyzed larch wood samples from trees aged 48 years, collected from six different provenances in Poland. Diameter at breast height (DBH) and tree height were used to calculate the parameters for sample trees, from which a 70 cm segment was cut, from breast height upwards (up to 2 m of tree height). Samples with dimensions 20 × 20 × 30 mm were obtained from the material. Sample volume was determined by stereometry. Relative density was determined for 890 samples. The highest wood density was found in trees from Czerniejewo, and the lowest in trees from Rawa Mazowiecka. Analysis of variance, including the mean wood density values of trees, did not demonstrate significant differences between provenances in terms of this characteristic. Mean relative density was higher in larch wood samples from the heartwood zone. The density of samples cut closer to the bark was lower, as the value was affected by the large content of sapwood. A relation was found between the provenances from which the study material was sourced and the relative density of wood

Moderate Diversity in Forest Structure and Its Low Dynamics Are Favored by Uneven-Aged Silviculture—The Lesson from Medium-Term Experiment

For several decades, there has been growing interest in highly diversified forests as a result of their management using the so-called uneven-aged silviculture. Such management and forests resulting from its application fulfil the purpose of forest ecosystem protection without significant limitation of the other forest functions and services. The usefulness of such silvicultural system depends largely on the species composition of the stand. In Poland, this system has been used primarily in silver fir (Abies alba Mill.)-dominated forests with an admixture of other shade-tolerant tree species and rather small admixture of light-demanding species. In our study, we analyzed the structure of fir-dominated uneven-aged forest consisting of a certain mix of eight tree species with different light-requirements, in which uneven-aged silviculture was performed for over two decades. The analysis of stand structure concerned three aspects of the forest structure: species diversity, spatial pattern of tree distribution, and tree size diversity. On the basis of three stand inventories, we captured the mid-term dynamics of the stand structure under moderate human pressure conditions. The results showed that the stand was characterized by high growing stock, with stable growth over the entire period. The silver fir was the dominant tree species, but the Scots pine and pedunculate oak also played an important role. However, the silver fir was abundant in the ingrowth class, whereas the pine and oak were absent or very rare in this stand strata. Noteworthy is the increasing importance of the European hornbeam, which is particularly evident in the ingrowth class; its abundance was twice that of the silver fir. The results clearly demonstrated that within 24 years, the share of light-demanding tree species in the forest clearly decreased, while that of shade-tolerant species clearly increased. Structural parameters showed a moderate tree-size diversity, despite the high species richness of the forest. This was mainly the result of selection cuttings, which clearly decreased tree-size variability after the second period of study. However, selection cuttings did not favor regeneration establishment, especially that of light-demanding tree species, whose role in the stand is assumed to be only minor in the future. The relatively high level of volume growth indicated that cutting intensity may be increased. More intense selection cuttings would also improve the stand structure by providing better light conditions for potential regeneration of different tree species, also light-adapted ones

Effect of Irrigation Dose on Powdery Mildew Incidence and Root Biomass of Sessile Oaks (Quercus petraea (Matt.) Liebl.)

The sessile oak is one of the most significant forest tree species in Europe. This species is vulnerable to various stresses, among which drought and powdery mildew have been the most serious threats. The aim of this study was to determine the influence of irrigation levels (overhead sprinklers) on the damage caused by powdery mildew to Quercus petraea growing in a nursery setting. Four irrigation rates were used: 100%, 75%, 50% and 25% of the full rate. The area of the leaves was measured and the ratio between the dry mass of the roots and the dry mass of the entire plant was calculated after the growing season in years’ 2015 and 2016. Limiting the total amount of water provided to a level between 53.6 mm × m−2 and 83.6 mm × m−2, particularly in the months when total precipitation was low (VII and VIII 2015), a supplemental irrigation rate between 3 and 9 mm × m−2 resulted in a lower severity of oak powdery mildew on leaves and lead to a favorable allocation of the biomass of the sessile oak seedlings to the root system. The severity of infection on oak leaf blades was lower when irrigation rates were reduced. The greatest mean degree of infestation in 2015 was noted in the 100% irrigation rate (14.6%), 75% (6.25%), 50% (4.35%) and 25% (5.47%). In 2016, there was no significant difference between the mean area of leaves infected by powdery mildew depending on the applied irrigation rate. The shoot-root biomass rate showed greater variation under limited irrigation rates. Controlling the irrigation rate can become an effective component of integrated protection strategies against this pathogen

Northern Provenances of Silver Fir Differ with Acclimation to Contrasting Light Regimes

Phenotypic differentiation of Abies alba was identified among selected provenances originating from the northern edge of this species’ natural geographic range. We posited that although the seed sources of the study populations were not geographically distant, progenies would differ with respect to growth, needle pigment concentration, and values of photochemical parameters in response to contrasting light conditions. Potted seedlings of six provenances were grown for two seasons under low light (LL, 40% of full irradiance) or high light (HL, 100% of full irradiance). The results showed that the provenances differed in diameter at root collar (DRC) and in relative growth rates of height (RGR). Seedlings grown in full light had a greater mean value of DRC than those in LL. LL increased total needle chlorophyll (Chltot) and carotenoid concentrations compared with HL, and Chltot was modified by the provenance of the seedlings. The provenance “Syców”, localized at the northern limit of the species range, showed the lowest value of maximal electron transfer rate (ETRmax) and lower values of growth parameters compared with the other study provenances. Relative growth rate, Chltot, and non-photochemical quenching of fluorescence (NPQ) were correlated with some climatic characteristics of seed stands and formed clusters indicating the local adaptation of the study populations. These results provide evidence of low intraspecific A. alba differentiation in terms of growth dynamics, photochemical capacity, and tolerance to different light regimes. The intraspecific diversity found in our study among the northern lead populations could be, however, important for the natural expansion of this species further north and for the selection of provenances to be used in the programme of the A. alba restoration in the Sudety Mountains, southern Poland, where decline of this species has been observed

Assessment of the height stability in progeny of Fagus sylvatica L. populations using the GGE biplot method

Forecasted climate changes demand selection of populations (seed stands) and genotypes (plus trees) best adapted to changing environmental conditions and displaying limited genotype × environment (G×E) interaction. Analysis of multi-environment trials (METs) allows to recognize differences between populations and environments, as well as G×E interaction. To define stability of tree height we used a GGE biplot graphic method based on the results of measurement of 5- and 10-year-old trees originating from 30 European beech populations tested at three experimental sites. Majority of variance was explained in terms of the impact of environment. The studied environments were characterised by a similar discriminating ability and representativeness of growth conditions. Two mega-environments were identified as the studied populations of beech differed in their adaptation to local growth conditions. The analysed set of populations included those growing particularly well under the specific environmental conditions, and others displaying more general adaptability. The GGE biplot method is useful in breeding of forest trees