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Insect infestation triggers multiple defense responses in plants, both locally at the infection site and systemically throughout the plant, including the production of feeding deterrents, toxins, defensive proteins, enzymes, and secondary metabolites. Our study aimed to compare the endogenous levels of antioxidative enzymes, photosynthetic pigments, phytohormones, total phenols, and flavonoids in bark-beetle-infested and uninfested trees. We evaluated the surviving trees in bark-beetle-infested stands, assessing both the condition and defense of uninfested and infested beech (Fagus sylvatica), pine (Pinus sylvestris), and fir (Abies alba) trees. Sampling was performed at six affected sites in the Czech Republic, targeting trees that were resilient to significant health deterioration caused by abiotic and biotic factors. The results showed different levels of most of the measured compounds in the three species. Among all the tested species, photosynthetic pigment levels showed the strongest association with infestation status, which was generally lower in the infested plants. For chlorophyll a, extremely significant reductions were observed from 123 ± 20.6 to 101 ± 17.9 μg/g dry weight (DW) in pine, from 231 ± 33.1 to 199 ± 22.2 μg/g DW in beech, and from 60 ± 5.66 to 51.3 ± 6.27 μg/g DW in fir. In contrast, enzymatic activities indicated only isolated instances of significant association, whereas antioxidative properties (total phenolic content, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were not significantly associated with infestation status. There was a statistically significant increase in glutathione reductase activity in infested fir and pine trees. However, this difference was not statistically significant in beech. In contrast, a significant increase in superoxide dismutase activity was detected in infected beech trees. Phytohormones have emerged as the most diverse group of analyzed compounds. Cytokinins were the most distinct, with many of them being significantly increased in infested pines, whereas both beech and fir showed only one significant association. Additionally, derivatives of jasmonic acid also showed a distinct pattern of change associated with bark beetle infestation, with the levels of three out of the four analyzed jasmonates being significantly decreased in infested pines, whereas no effects were observed in beeches and firs. Notably, many phytohormones were significantly elevated in the infested pine, whereas both beech and fir exhibited only one significant association. Overall, the data showed that pines responded differently to bark beetles than to beeches or firs. The greatest changes in phytohormones were observed in pine, whereas the most significant changes in photosynthetic pigments were observed in beech and fir trees. [ABSTRACT FROM AUTHOR]

Abies nebrodensis is a species of fir endemic to Sicily, represented by only 30 trees in the natural population and is currently classified as critically endangered by IUCN. In such context, monitoring its health status is essential for the proper management and preservation of this species. Phytosanitary surveys of trees of the natural population of A. nebrodensis and on potted plants raised in the local forest nursery were carried out, and the phyllosphere fungal community was investigated. The health condition of trees in the natural population were fairly good, with needle reddening and blight as the most frequently observed symptoms on the foliage, while in the nursery similar disorders were registered on about the 1.3% of potted plants. Results on fungal isolations highlighted the presence of species belonging to Valsa, Cytospora (which includes anamorphs of Valsa) and Rhizosphaera genera as the most represented on both reddened and green needles; these results suggest that these fungi likely live as endophytes, resuming their growth when needles are affected by environmental stressors such as wind, hail, mechanical wounds and do not represent a biotic constraint for A. nebrodensis. The disorders observed appear mostly as a consequence of the harsh site in which the relic species lives. Together with the fungal community observed on symptomatic and healthy needles, they indicate that A. nebrodensis adapted and tolerates its altered habitat. [ABSTRACT FROM AUTHOR]

The silver fir (Abies alba Mill.) is among the most valuable conifers in Europe for ecological and economic reasons. Throughout the course of history, primarily in the 20th century, its share in stands has been declining due to ill-suited management practices, especially clear-cut management, air pollution (SO2 and NOX emissions), and wildlife-induced damage. This literature review compiles findings from 338 scientific papers. It describes futures for silver fir and its distribution, ecological requirements, threats and diseases, seed production and nurseries, and forest management practices with emphasis on ongoing climate change. Based on recent knowledge of fir ecology and population dynamics, small-scale shelterwood and selection management have been introduced in fir stands, which have also stabilized them. Fir is an essential species for maintaining high stability and biodiversity, especially on planosols and in waterlogged habitats. Owing to its shade tolerance and environmental plasticity, it can coexist very well with many tree species in mixtures, which can increase the productive potential of stands within the natural range in Europe. The average stand volume of mature fir stands ranges from 237–657 m3 ha−1. For its successful natural regeneration, it is essential to reduce cloven-hoofed game and thus prevent bud browsing damage. The attractiveness of fir in terms of heavy browsing is the highest of all conifers (52% damage). On the other hand, fir is a species relatively resistant to bark stripping and the spread of secondary rot compared with Norway spruce (Picea abies [L.] Karst.). Under global climate change, fir is expected to shift to higher elevations with sufficient precipitation, while in the southern part of its natural range or at lower elevations, outside water-influenced habitats, it is likely to decline. Climate change is intricately linked to the heightened prevalence of forest pathogens with significant damage potential in Europe, necessitating careful consideration and strategic adaptation within management practices of fir forests. [ABSTRACT FROM AUTHOR]

Predicting global change mitigations based on environmental variables, like temperature and water availability, although yielding insightful hypothesis still lacks the integration of environmental responses. Physiological limits should be assessed to obtain a complete representation of a species' fundamental niche. Detailed ecophysiological studies on the response of trees along the latitudinal gradient are rare. They could shed light on the behaviour under different light intensities and other studied traits. The forests of the Dinaric Mountains and the Carpathians represent the largest contiguous forest complexes in south-eastern Europe. In uneven-aged Carpathian (8 plots) and Dinaric Mountain (11 plots) forests, net assimilation (Amax) and maximum quantum yield (Φ) were measured for beech and fir in three predefined light intensity categories according to the indirect site factor (ISF%) obtained by the analysis of hemispherical photographs in managed and old growth forests, all located above 800ma.s.l. The measurements were carried out under fixed environmental conditions in each light category per plot for three consecutive years. Data from the last 50-year average period from the CRU TS 4.01 dataset were used for the comparison between Amax, Φ, and climate. The highest Φ for beech were observed in the central part of the Dinaric Mountains and in the south westernmost and northwesternmost part of the Carpathians for both beech and fir, while theywere highest for fir in the Dinaric Mountains in the northwesternmost part of the study area. The Φ-value of beech decreased in both complexes with increasing mean annual temperature and was highest in the open landscape. For fir in the Carpathians, Φ decreased with increasing mean annual temperature, while in the Dinaric Mountains it increased with higher temperature and showed a more scattered response compared to the Carpathians. Short-term ecophysiological responses of beech and fir were consistent to long-term radial growth observations observed on same locations. The results may provide a basis and an indication of the future response of two tree species in their biogeographical range to climate change in terms of competitiveness, existence and consequently forest management decisions. [ABSTRACT FROM AUTHOR]

Gremmenia abietis (Dearn.) Crous (syn: Phacidium abietis) was originally described in North America to accommodate the species associated with snow blight of Abies and Pseudotsuga spp. In Japan, this species was first observed on the dead needles on Abies sachalinensis and Picea jezoensis var. jezoensis in 1969. However, the identity of Japanese species was unclear due to the lack of molecular data and the absence of anamorph description. In this study, we collected fresh specimens from various conifer species (A. sachalinensis, A. veitchii, Pic. jezoensis var. jezoensis, Pic. jezoensis var. hondoensis, Pinus koraiensis, and Pin. pumila) in Japan and revised the taxonomy based on morphological and phylogenetic analyses. Phylogenetic analyses based on nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and RNA polymerase II second largest subunit (RPB2) regions indicated that the species belongs to Phacidiaceae. Conidiomata formed in vitro produced pyriform, hyaline conidia without mucoid appendage, which distinguished the species from phylogenetically related genera. Consequently, we established Chionobium takahashii to accommodate the snow blight fungus in Japan. Further phylogenetic analyses also indicated that C. takahashii includes several distinct clades corresponding to the host genera (Abies, Picea, Pinus). Morphological differences among those clades were unclear, suggesting that C. takahashii may contain host-specific cryptic species. [ABSTRACT FROM AUTHOR]

Key message: This study compares the measured radial variation in wood stiffness, strength, and density of noble fir, Norway spruce, western hemlock, and western red cedar by developing mixed-effects models for each property using age as the explanatory variable. These models could be used to simulate the effect of rotation length and species choice on sawn wood properties. Context: Timber production in Great Britain relies primarily on Sitka spruce. The use of multiple species is desirable to mitigate against biotic and abiotic risks posed to a single species. When considering alternative species, quantifying and modeling radial variation in wood properties is important to determine the potential for sawn timber production at a given rotation length. Aims: To build empirical models for the radial variation in wood properties that can account for species. Methods: Clear-wood samples were produced along radial transects in trees from four conifer species: Abies procera Rehder, Picea abies (L.) Karst, Tsuga heterophylla (Raf.) Sarg., Thuja plicata Donn. ex D.Don. Modulus of Elasticity, Modulus of Rupture, and density were measured on each species according to established standards. Mixed-effects models were built using ring numbers from the pith and species as explanatory variables. Results: The same model forms could be used across the four species. Nonlinear models were developed for the Modulus of Elasticity and density. For the Modulus of Rupture, a linear model was most appropriate. The effect of species in the models was significant. Conclusion: At similar rotation lengths, noble fir, Norway spruce, and western hemlock can produce timber with comparable properties to Sitka spruce. Overall, western red cedar would have worse properties for structural use. [ABSTRACT FROM AUTHOR]

This study investigated the physicochemical properties of fir (Abies alba Mill.) honeydew honey (FHH) and its biological activity against the leading foodborne bacterium Campylobacter jejuni. Antibacterial activity, bacterial growth and anti-adhesion tests were performed in Mueller Hinton (MH) broth and cow's milk used as a food model. FHH from the mountainous region of Croatia showed antibacterial activity against C. jejuni in MH broth and milk, with the minimal inhibitory concentration (MIC) values ranging from 12.5 to 50 mg/mL. A transmission electron microscopy (TEM) analysis of C. jejuni cells showed severe cellular damage after exposure to the tested honeydew honey. FHH in concentrations of 3 and 5% (w/v) inhibited growth and prevented adhesion to the polystyrene surface at a concentration of 25 mg/mL or lower of the bacterium C. jejuni in MH broth and milk. The anti-adhesion effect was more pronounced in the milk than in the MH broth. These results suggest that FHH has potent antibacterial activity against C. jejuni due to its particular physicochemical properties. [ABSTRACT FROM AUTHOR]

We present the first high-resolution Holocene pollen, plant-macrofossil, and charcoal records from the upper-montane zone in the central Dinaric Alps. Drawing on these new records from well-dated lacustrine sediments of Zminje Jezero (ca. 1500 m a.s.l.; Montenegro) and on independent chironomid-inferred summer temperatures, we explore long-term ecosystem responses to variations in climate, fire disturbances and land use, as well as legacy effects of past environmental changes. A mixed spruce-fir forest established in the upper-montane zone around 9500 cal BP, and Fagus sylvatica became co-dominant with the two conifers after 5000 cal BP. Prehistoric land-use pressure was overall remarkably low, but increased since 2000 cal BP and was highest after the Middle Ages. We found a significant positive relationship between biomass burning and summer temperature, indicating that fires were mostly climate driven. Picea abies was insensitive to summer temperature, biomass burning and human impact, which supports the view that spruce forests may not be significantly impacted by fire. In contrast, Abies alba and other disturbance-sensitive trees (Tilia, Ulmus, Fraxinus excelsior -type) show significant negative responses to land-use pressure and positive responses to summer temperature. This supports the notion that these species may be well-adapted to warmer-than present summer temperatures and that their populations declined in recent millennia due to land-use activities. Conversely, F. sylvatica was sensitive to summer temperatures but was promoted by low biomass burning, indicating that its expansion in the spruce-fir dominated forest was enhanced by the onset of cooler and possibly also moister climatic conditions as well as by fire disturbances. [ABSTRACT FROM AUTHOR]

The forest areas and, more generally, the mountain territory, produce a significant flow of ecosystem services from which the entire community benefits. In October 2018, northeastern Italy was hit by an extreme meteorological event, the Vaia windstorm, which affected 91 municipalities in the Veneto region and destroyed nearly 20% of its forests in some areas, mainly composed of spruce (Picea abies) and fir (Abies alba). This study aims to understand and analyze what the affected population preferences are in relation to different reforestation strategies in the forests affected by the Vaia windstorm in order to have more resilient forests in the future. In this regard, a survey including a choice experiment was carried out in May 2022 involving a sample of 830 residents in the Veneto region. From our results, it emerges that a policy characterized by a mixed reforestation solution of 50% of planted area and 50% natural with fallen trees removed is the respondents' favorite reforestation policy, bringing an average benefit per year per family equal to EUR 226.5. Considering the reforestation policy proposed, the attribute considered most important (34%) was the presence of a natural forest with the removal of fallen plants, followed by reforestation with a planted forest (24%), while in third place we find the removal of fallen trees in forests damaged to a minor extent by the Vaia storm (20%). [ABSTRACT FROM AUTHOR]

Litter decomposition is a key pathway of metal cycling in terrestrial ecosystems, yet little is known about the dynamics of metals in decomposing roots. A two-year decomposition experiment was conducted to investigate the temporal dynamics of nine metals (Ca, K, Mg, Fe, Al, Mn, Cr, Cu, and Pb) in decomposing roots of three diameter classes (0–2 mm, 2–5 mm, and 5–10 mm) in two subalpine coniferous tree species (Picea asperata and Abies faxoniana) on the eastern Tibetan Plateau of China. Regardless of tree species and root diameters, macro metals (Ca, K, and Mg) and Cu often released over the experimental period and their remaining were 87.7%, 12.5%, 69.4%, and 47.98%, respectively. However, trace metals (Fe, Al, Mn, Cr, and Pb) generally accumulated during the decomposition process and their remaining were 159.6%, 121.5%, 196.4%, 119.6%, and 124.3%, respectively. The concentrations of Ca, K, Mg, Fe, and Al often decreased with increasing root diameters over the experimental period. For Picea asperata, the Ca, K, Fe, and Pb remaining were higher in the 5–10 mm than 0–5 mm roots, but contrasting trends were found for Mg, Mn, Cr, and Cu. For Abies faxoniana, the 5–10 mm roots had lower macronutrients (Ca, K, and Mg) but higher trace metals (Fe, Al, Mn, Cr, Cu, and Pb) remaining compared to 0–5 mm roots. Taken together, root diameter had pronounced influences on metal dynamics, depending on metallic properties, initial root quality, and/or decomposition period. Root initial chemistry (e.g., C, Mn and lignin) were significantly correlated with the metal remaining during the decomposition. Our findings address the importance of root diameter in understanding metal cycling via root decomposition pathways in forest ecosystems. [ABSTRACT FROM AUTHOR]

The article presents the results of the search for microsatellite or simple sequence repeat (SSR) loci with tri-, tetra-, penta- and hexanucleotide tandem repeat motifs in the draft de novo assembly of the Siberian fir (Abies sibirica Ledeb.) genome and the development of convenient relatively highly and moderately polymorphic markers that can be easily genotyped even by simple gel electrophoresis. In total, 64 pairs of oligonucleotide polymerase chain reaction (PCR) primers for 32 detected microsatellite loci were designed and tested. Based on the testing results, 10 most promising polymorphic loci were selected and genotyped in eight natural populations of Siberian fir. Homologous microsatellite loci in the genome of European silver fir (Abies alba Mill.) were also identified by mapping Siberian fir contigs, containing SSR loci to the European silver fir genome assembly. A multiplex panel of 14 universal microsatellite loci was developed and genotyped in samples from four natural populations of A. alba and a small sample of eight Nordmann fir (Abies nordmanniana (Steven) Spach) trees. [ABSTRACT FROM AUTHOR]

The chemical content of essential oils (EO) obtained from the leaves of four Pinaceae (Abies alba, Picea abies, Pinus cembra and Pinus mugo) was investigated by SPME-GC-MS technique. The vapor phase was characterized by the monoterpenes with values higher than 95.0%. Among them, α-pinene (24.7–48.5%), limonene (17.2–33.1%) and β-myrcene (9.2–27.8%) were the most abundant. The monoterpenic fraction prevailed over the sesquiterpenic one (≥74.7%) in the EO liquid phase. Limonene was the major compound in A. alba (30.4%), P. abies (20.3%) and P. mugo (78.5%), while α-pinene in P. cembra (36.2%). Regarding the phytotoxic properties, EOs were studied at different doses (2–100 μL) and concentrations (2–20/100 μL/mL). All EOs were found to be significantly active (p-value ˂ 0.05) against the two recipient species in a dose-dependent way. In pre-emergence tests, germination of Lolium multiflorum and Sinapis alba was reduced by up to 62–66% and 65–82%, respectively, as well as their growth by up to 60–74% and 65–67%, due to the effects of compounds in both the vapor and liquid phases. In post-emergence conditions, at the highest concentration, the phytotoxicity of EOs caused heavy symptoms and, in the case of S. alba, A. alba EO completely destroyed (100%) the treated seedlings. [ABSTRACT FROM AUTHOR]

Hybridization is a process of great importance in the ecology and evolution of plants. However, identifying hybrids is not an easy task, especially in cases of sympatry. Such cases are the Abies taxa in Greece; Silver fir (A. alba), Greek fir (A. cephalonica) and King Boris fir (A. × borisii-regis). The latter has been characterized as a hybrid between the first two species as its morphological traits are either a combination of the parental ones or intermediate. Besides the morphological traits, A. × borisii-regis has so far been identified only at the population level, with biochemical and DNA markers. Here, we describe the identification of A. × borisii-regis at the individual level by employing a species-specific marker in the cpDNA and another in mtDNA, taking advantage of their uniparental inheritance mode from the paternal and the maternal parent, respectively. In addition, based on these markers, essential information emerges on the distribution and the mtDNA diversity of the Abies taxa in Greece. [ABSTRACT FROM AUTHOR]

Although many studies have evaluated plant ecophysiological responses to increasing atmospheric carbon dioxide concentration (CO2) and increasing temperature, few studies have addressed the interactive effects of these two factors, especially on high-altitude trees that are more sensitive. To address this issue, we used Abies faxoniana and Picea purpurea seedlings to evaluate the effects of elevated CO2 (CeTa, 700 ppm), elevated temperature (CaTe, 2 °C above ambient temperature) and elevated CO2 combined with elevated temperature (CeTe) on plant growth, morphology and physiological responses. We found that CaTe increased conifer total dry mass, specific root length, net photosynthesis rate and translocation rates of 15NH4+ and 15NO3−, but CeTe had stronger responses (except net photosynthesis rate of A. faxoniana). These results indicate that the effect of elevated temperature on the growth and physiological responses is enhanced by elevated CO2. Furthermore, effect of CeTe on physiological traits was higher in P. purpurea , which possessed a higher total dry mass, specific leaf area, water use efficiency (δ 13C), δ 15NO3−-N level, translocation rates of 15NH4+ and 15NO3− and total nonstructural carbohydrates than A. faxoniana. Overall, these findings suggest that the interactive effects of CO2 × temperature should be considered when assessing conifer responses to future climates. [ABSTRACT FROM AUTHOR]

Litterfall of silver fir contributes to development of forest floor similarly like Norway spruce litterfall does. The nutrient return to soil can be intensified by mixing these conifers with other tree species whose effects on soil are positive; our study deals with European rowan. The study aimed at firs and rowans in alternating rows (Fi-Ro) compared to the monospecific plantation of fir (Fi) at two former meadow sites with the stands of 20 and 17 years of age, respectively. Both organic forest floor and its mineral subsurface were sampled. Rowan admixed to the silver fir plantation improved both the uppermost layer and the topsoil as higher pH, more favourable soil-sorption properties and higher plant available magnesium were found below Fi-Ro compared to Fi. Fine dry matter was higher below Fi, which was reflected in higher organic carbon (Cox), combustible matter and nitrogen pools. Besides the effects of trees on the soil, silvicultural issues such as renewal costs and tree species performance in monospecific and mixed stands were presented and discussed. [ABSTRACT FROM AUTHOR]

Pine wilt disease (PWD) caused by the pine wood nematode (PWN) is China's most serious forest disease in recent decades. Its complex disease system with unclear pathogenesis and differentiated pathogenicity makes it challenging to manage and control. PWD has spread rapidly in Northeast and Northwest China in recent years, exceeding previous predictions and the traditional understanding of its potential distribution. This paper reviewed the comprehensive risk of PWD in Northeast and Northwest China through the occurrence of influencing factors. Regarding PWN's temperature resistance, all regions of China are suitable for PWD. In terms of altitude, the PWD system is mainly distributed below 1000 m. In China, Pinus and Larix species are confirmed host trees of PWN, while Monochamus alternatus and M. saltuarius are confirmed vector insects of PWN. In this case, PWD may occur in all low-altitude pine forests in China. Northeast China has a higher risk than Northwest China due to its distribution of suitable host trees and vector beetles at low altitudes. To confront the threat, two scientific bottlenecks are required to be demonstrated. The first is the pathogenicity of Chinese PWN strains to Chinese Picea and Abies species. The other is the geographical distribution and highest altitude distribution of other Monochamus species in the Palaearctic region of China and their PWN transmission ability. We also suggest strengthening plant quarantining in Northeast China. In conclusion, this review comprehensively analyzes the risk of PWD in Northeast and Northwest China in terms of temperature, altitude, host trees, and vector insects. It provides a new perspective and reference for the management and research of PWD in China. [ABSTRACT FROM AUTHOR]

Silver fir is one of the most important tree species not only in Bosnia and Herzegovina, but also in whole of Europe. For natural regeneration of fir, the most important factors are site condition, share of fir in the stand and tree species composition. The aim of this study was to determine if there are statistically important differences in the number of seedlings and height increment at different competition situations between adult trees. Study area was located at Bjelašnica mountain. Data were collected on circular plots with a radius of 12.62m for trees with dbh above 5 cm, and radius 3 m for regeneration layer. The competition is expressed using Hegyi competition index, where for the calculation a dominant tree from each quadrant was used. We analysed the total number of fir individuals in regeneration layer and height increment for categories 50-130 cm height and 0.1-5 cm dbh. The results showed that there are no statistically significant differences in the number of for seedlings at different values of the Hegye index. Statistically significant differences were found in terms of height increment. Height increment decreased with increasing competition between trees. [ABSTRACT FROM AUTHOR]

Two-stage forest regeneration using preparatory stands presents potentially suitable way of an introduction of silver fir (Abies alba) in largescaled clear-cut areas of calamity origin. Th e objective of this study was the verification of four-year-old fir underplanting reactions at nutrient rich site to the preparatory stands environment featuring three pioneering species of various stocking density (5, 7, 10) compared with plantings in small area clearing (0.1 ha). The fir mortalities were low both in all stand treatments and in the clearing. The fir height and root diameter increments under birches declined with higher stocking density. Under rowan, the highest increments occurred under preparatory stand with stocking density of 7. Minimal fir increment reactions to the various stocking density of the preparatory stands were observed under alder trees. The development of the crown width mostly correlated with the fir height. Development of the needle lengths, depending on the stocking density of preparatory stands, differed under birches from rowan shelter, while there were no differences in this parameter under alder treatments. The research showed that in present conditions fir plantings in small area clearings or under about 15-year-old preparatory birch stands, having stocking density reduced to one half, can be recommended from fir prosperity perspective. [ABSTRACT FROM AUTHOR]

Very limited information is available on the drought tolerance of European beech and silver fir in mixed cultivation, both for mature forests and natural regeneration. Particularly, little information is available regarding the significance on memory effects of drought exposure. Therefore, drought memory was analyzed in seedlings of these species grown in mixed cultivation in the present study. The results showed that previous-year drought hardening mediated enhanced biomass accumulation of beech leaves and root in the subsequent year, but did not impact fir growth. Total carbon (C) content was decreased by drought hardening in both the leaves and roots of beech and previous-year needles and roots of fir, in beech probably as a consequence of increased growth. Previous-year drought hardening had no significant effect on relative water contents, total nitrogen (N), or soluble protein contents in leaves and roots of beech and fir, but resulted in decreased total amino acid contents of beech leaves and fir needles. It further reduced structural N in current-year fir needles and decreased C/N ratios in roots of both beech and silver fir seedlings. Generally, the number of interspecific neighbors had no considerable effect on biomass or total C or N contents, as well as N partitioning in leaves and roots of beech and fir seedlings. The present study highlights that drought hardening induces memory effects in European beech and silver fir seedlings in their mixture in the subsequent year of growth, but these memory effects are stronger in beech than in fir. [ABSTRACT FROM AUTHOR]

Grand fir (Abies grandis/Dougl. ex D. Don/Lindl.) represents the North American species that has the potential to replace and complement to some extent several commercial European species, in particular, Norway spruce and silver fir. This is not only due to its high production potential but also because of its favorable effect on the soil compared to spruce or pine. We tested sample trees from these tree species growing in the same location for physical and mechanical wood properties and evaluated the effect of the thermal treatment (180 °C and 200 °C) on their wood. Wood density, swelling, surface properties, strength, and stiffness were the properties used to find the differences among species. Grand fir obtained higher values for density and compressive strength compared to silver fir. For the remaining properties, these tree species are comparable, except for toughness, which was significantly lower for grand fir. Grand fir wood was even comparable with Norway spruce in the case of density and compressive strength. The thermal treatment resulted in a decrease in density, swelling, wettability, modulus of rupture, and toughness while increasing compressive strength. The effect of the thermal treatment was similar for all tested species. From this perspective, grand fir represents a potential substitute for the timber of endangered European commercial conifers. [ABSTRACT FROM AUTHOR]

In recent decades, in many regions of the planet, there has been a widespread deterioration in the health condition and dieback of dark coniferous forests, caused by the combined action of various stress factors of biotic and abiotic origin. Forests with the participation of species of the genus Abies Mill. are particularly prone to degradation and dieback. The aim of the research is to study the symptoms of bacterial wetwood disease of Abies alba in the Ivano-Frankivsk region (state enterprise 'Kutske forestry') and to determine the anatomical, morphological and cultural properties of the pathogen. Some of the common symptoms of the disease include cracks and ulcers on the trunks with exfoliated rhytidome and exudate secretion, massive development of epicormic shoots, saturated xylem and phloem, wet rot with a characteristic odour of fermentation and pathological nucleus. Based on the syntaxonomic analysis of fir forests, an attempt has been made to identify the objective causes that lead to excessive development of phytopathogens and dieback of Abies alba. Our research established that the primary cause of dieback of Abies alba Mill. forests is a systemic, vascular–parenchymal disease known as bacterial wetwood of fir, which affects all plant tissues at all stages of ontogenesis. We isolated and experimentally confirmed that the causative agent of the disease is a phytopathogenic bacterium Lelliottia nimipressuralis (Carter 1945) Brady et al. 2013, which also causes bacterial wetwood in many species of forest woody plants, and also studied its common morphological, physiological and biochemical properties. [ABSTRACT FROM AUTHOR]

To alleviate the enhanced frequency, duration, and intensity of drought as a consequence of global warming, admixing drought-sensitive European beech (Fagus sylvatica L.) with deep rooting silver fir (Abies alba Mill.) has been proposed. However, information on the performance of the admixtures of seedlings of these tree species at limited water availability has so far not been reported. In the present study, we investigated the significance of water deprivation in mixtures of beech and fir seedlings on the foliar relative water content (RWC), δ13C signature, total C and N contents, and C:N ratios of both species in a drought-rewetting cycle. Surprisingly, moderate drought triggered increased RWC in beech leaves and current year fir needles indicating drought hardening. The enhanced foliar RWC was preserved after rewatering in beech leaves, but not in current year fir needles. Drought did not significantly affect δ13C abundance in beech leaves, but enhanced the δ13C abundance (less negative values) in current and one-year old fir needles, indicating stomatal control in fir needles but not in beech leaves upon moderate drought. Total C contents of beech leaves were significantly increased upon drought and rewatering, but remained constant in fir needles. Foliar total N increased in both species upon drought and decreased upon rewatering. Accordingly, C:N ratios decreased in response to drought and recovered after rewatering. These results suggest that drought hardening may be achieved at least partially via osmotic adjustment by different compatible solutes in beech leaves and fir needles. No apparent effects of the number of neighbours were observed, although more fir neighbours tended to increase the RWC and total C contents of beech leaves. These results indicate that drought hardening in mixtures of beech and fir seedlings is largely independent of the number of interspecies neighbours. [ABSTRACT FROM AUTHOR]

Cross-laminated timber (CLT) can be used as an element in various parts of timber structures, such as bridges. Fast-growing hardwood species, like poplar, are useful in regions where there is a lack of wood resources. In this study, the withdrawal resistance of nine types of conventional fasteners (stainless-steel nails, concrete nails and screws, drywall screws, three types of partially and fully threaded wood screws, and two types of lag screws), with three loading directions (parallel to the grain, perpendicular to the surface, and tangential), and two layer arrangements (0-90-0° and 0-45-0°) in 3-ply CLTs made of poplar as a fast-growing species and fir as a common species in manufacturing of CLT was investigated. Lag screws (10 mm) displayed the highest withdrawal resistance (145.77 N), whereas steel nails had the lowest (13.13 N), according to the main effect analysis. Furthermore, fasteners loaded perpendicular to the grain (perpendicular to the surface and tangential) had higher withdrawal resistance than those loaded parallel to the grain (edge). In terms of the layer arrangement, fasteners in CLTs manufactured from poplar wood (0-45-0°) had the greatest withdrawal resistance, followed by CLTs manufactured from poplar wood in the (0-90-0°) arrangement, and finally, those made from fir wood in the (0-90-0°) arrangement. The fastener type had the most significant impact on the withdrawal resistance, so changing the fastener type from nails to screws increased it by about 5–11 times, which is consistent with other studies. The results showed that poplar, a fast-growth species, is a proper wood for manufacturing CLTs in terms of fastener withdrawal performance. [ABSTRACT FROM AUTHOR]

Plant nitrogen (N) uptake is affected by plant–plant interactions, but the mechanisms remain unknown. A 15N-labeled technique was used in a pot experiment to analyze the uptake rate of ammonium (NH4+) and nitrate (NO3−) by Abies faxoniana Rehd. et Wils and Picea asperata Mast. in single-plant mode, intraspecific and interspecific interactions. The results indicated that the effects of plant–plant interactions on N uptake rate depended on plant species and N forms. Picea asperata had a higher N uptake rate of both N forms than A. faxoniana , and both species preferred NO3−. Compared with single-plant mode, intraspecific interaction increased NH4+ uptake for A. faxoniana but reduced that for P. asperata , while it did not change NO3− uptake for the two species. The interspecific interaction enhanced N uptake of both N forms for A. faxoniana but did not affect the P. asperata compared with single-plant mode. NH4+ and NO3− uptake rates for the two species were regulated by root N concentration, root nitrate reductase activity, root vigor, soil pH and soil N availability under plant–plant interactions. Decreased NH4+ uptake rate for P. asperata under intraspecific interaction was induced by lower root N concentration and nitrate reductase activity. The positive effects of interspecific interaction on N uptake for A. faxoniana could be determined mainly by positive rhizosphere effects, such as high soil pH. From the perspective of root–soil interactions, our study provides insight into how plant–plant interactions affect N uptake, which can help to understand species coexistence and biodiversity maintenance in forest ecosystems. [ABSTRACT FROM AUTHOR]

Silver fir (Abies alba Mill.) is one of the most valuable and productive tree species across European mountains, that accomplish multiple economic, protective and ecologic functions. Alongside spruce (Picea abies (L.) Karst) and beech (Fagus sylvatica L.), silver fir is a characteristic species for the Romanian Carpathians. Although silver fir tree is recommended for the diversification of forests in order to increase the resistance to climate change, it is very sensitive to climatic excesses, especially those that proceed rapidly. Therefore, the aim of this study is to investigate both the environmental conditions and stand characteristics of fir from five mountain ranges of the Romanian Carpathians. The study is based on data recorded over a period of 10 years (1990–2000). As such, a total of 77,251 stands that occupy 211,954 hectares have been investigated in regard to silver fir behaviour. MATLAB scripts were used for analysing consistent data volumes as well as the impact of eight factors on the silver fir productivity (altitude, field aspect, field slope, soil type, participation percentage, road distance, structure and consistency). Our analysis has revealed that higher silver fir productivity is found at altitudes of up to 1200 m, on mid and upper slopes, on NW field aspects, on eutric cambisols and dystric cambisols, with a 10–20% participation in stand composition and in relatively-even aged stands with a full consistency. This study offers valuable insights for forest managers that require comprehensive information in adopting effective strategies to enhance forest resilience under climate change. [ABSTRACT FROM AUTHOR]

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Tricholoma vaccinum is an ectomycorrhizal basidiomycete with high host specificity. The slow-growing fungus is able to produce twenty sesquiterpenes, including α-barbatene, sativene, isocaryophyllene, α-cuprenene, β-cedrene, ß-copaene, 4-epi-α-acoradiene, and chamigrene in axenic culture. For the three major compounds, Δ6-protoilludene, β-barbatene, and an unidentified oxygenated sesquiterpene (m/z 218.18), changed production during co-cultivation with the ectomycorrhizal partner tree, Picea abies, could be shown with distinct dynamics. During the mycorrhizal growth of T. vaccinum–P. abies, Δ6-protoilludene and the oxygenated sesquiterpene appeared at similar times, which warranted further studies of potential biosynthesis genes. In silico analyses identified a putative protoilludene synthesis gene, pie1, as being up-regulated in the mycorrhizal stage, in addition to the previously identified, co-regulated geosmin synthase, ges1. We therefore hypothesize that the sesquiterpene synthase pie1 has an important role during mycorrhization, through Δ6-protoilludene and/or its accompanied oxygenated sesquiterpene production. [ABSTRACT FROM AUTHOR]

Key message: Different components of water balance and temperature reduce density and height growth of saplings of Picea abies (L.) H. Karst (Norway spruce), Abies alba Mill. (silver fir) and Fagus sylvatica L. (European beech) in mixed uneven-aged forests in the French Alps and Jura mountains. Ungulate browsing is an additional pressure on fir and beech that could jeopardise the renewal of these species in the future. Context: The uncertainty in tree recruitment rates raises questions about the factors affecting regeneration processes in forests. Factors such as climate, light, competition and ungulate browsing pressure may play an important role in determining regeneration, forest structures and thus future forest composition. Aims: The objective of this study was to quantify sapling densities and height increments of spruce, fir and beech and to identify dominant environmental variables influencing them in mixed uneven-aged forests in the French Alps and Jura mountains. Methods: Sapling height increment and density were recorded in 152 plots, and non-linear mixed models were obtained to establish relations between them and environmental factors known to affect regeneration, namely altitude, slope, aspect, canopy openness, soil characteristics, temperature, precipitation and ungulate browsing. Results: Regeneration density, varying from 0 to 7 saplings per m 2, decreased with sapling height and was also negatively affected for spruce by PET, but positively for fir by precipitation and for beech by mean annual soil water content. Height increment reached up to 50 cm annually, increasing with sapling height and canopy openness and decreasing under high maximum summer temperatures for spruce and beech. The statistical effect of different environmental variables varied slightly among species but trends were quite similar. Additionally, ungulate browsing was high, with fir being the most intensely browsed, followed closely by beech, while spruce was rarely browsed. Conclusions: All these results suggest that more temperature warming and a decrease in water availability could negatively impact sapling growth and density in the three species, with possible reduction of forest renewal fluxes. The observed increase of ungulate populations leading to increased browsing could be particularly detrimental to fir saplings. [ABSTRACT FROM AUTHOR]

Antioxidant and antifungal activities of three essential oils (EOs): Melaleuca ericifolia Smith (rosalina; REO), Melaleuca quinquenervia (niaouli; NEO) and Abies alba (fir; FEO) were determined. The antioxidant capacity was investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the disc diffusion method was applied to evaluate their antifungal efficacy (in four concentrations 62.5 µL/L, 125 µL/L, 250 µL/L, 500 µL/L used) against Penicillium (P.) expansum microscopic filamentous fungus isolated from bread samples. From the findings it can be clearly evident that antioxidant activities of the EOs were very weak with values ranging from 25.81 ± 7.8 TEAC (6.2 ± 1.4%; FEO) to 162.0 ± 2.1 TEAC (15.9 ± 0.4%; NEO). Regarding antifungal properties, our results revealed that the effects of the EOs on P. expansum growth inhibition were dose-dependent, and they were proportionally increased with increasing EOs concentrations. Detected inhibition zones ranged from 0.00 ± 0.00 mm (for all EOs at 62.5 µL/L) to 11.67 ± 1.15 mm (for REO at 500 µL/L). In conclusion, all analyzed EOs possess promising in vitro antifungal activity (despite their weak antioxidant capacity) suggesting their use as a promising natural preservative in the food industry. [ABSTRACT FROM AUTHOR]

The Barcode Index Numbers (BINs) are operational species units based on patterns of COI divergences that in most cases correspond to species. It has been repeatedly observed that more than one BIN can be found under the same species name particularly when large geographic scales are considered. One such case concerns Eupithecia conterminata, a species widespread in North European countries and restricted to mountainous regions in the rest of the continent, for which five BINs are found in Europe. In order to solve the question concerning the taxonomic status of these BINs and European populations, we employed an integrated approach by combining classical morphological traits (genitalia and wing markings) with those of molecular data, the latter involving both mitochondrial and nuclear genes. This approach allowed us to recognize two valid species in Europe, E. conterminata, currently known only in Fennoscandia, Baltic countries and Russia, and Eupithecia manniaria sp. rev., with distribution covering Central and South European countries. We furthermore synonymized Eupithecia pindosata syn. nov. from Greece with E. manniaria. The European range of these species and their mitochondrial diversity appear to be coherent with biogeographical histories of their foodplants Picea abies and Abies species. [ABSTRACT FROM AUTHOR]

Aims: We examined differences in life span among the dominant tree species (spruce, Picea abies; fir, Abies alba; beech, Fagus sylvatica; and maple, Acerpseudoplatanus) across primary mountain forests of Europe. We asked how disturbance history, lifetime growth patterns, and environmental factors influence life span. Locations: Balkan Mountains, Carpathian Mountains, Dinaric Mountains. Methods: Annual ring widths from 20,600 cores from primary forests were used to estimate tree life spans, growth trends, and disturbance history metrics. Mixed models were used to examine species‐specific differences in life span (i.e., defined as species‐specific 90th percentiles of age distributions), and how metrics of radial growth, disturbance parameters, and selected environmental factors influence life span. Results: While only a few beech trees surpassed 500 years, individuals of all four species were older than 400 years. There were significant differences in life span among the four species (beech > fir > spruce > maple), indicating life history differentiation in life span. Trees were less likely to reach old age in areas affected by more severe disturbance events, whereas individuals that experienced periods of slow growth and multiple episodes of suppression and release were more likely to reach old age. Aside from a weak but significant negative effect of vegetation season temperature on fir and maple life span, no other environmental factors included in the analysis influenced life span. Conclusions: Our results indicate species‐specific biological differences in life span, which may play a role in facilitating tree species coexistence in mixed temperate forests. Finally, natural disturbance regimes were a key driver of life span, which could have implications for forest dynamics if regimes shift under global change. [ABSTRACT FROM AUTHOR]

Suillus is among the best-known examples of an ectomycorrhizal (ECM) fungal genus that demonstrates a high degree of host specificity. Currently recognized host genera of Suillus include Larix, Pinus, and Pseudotsuga, which all belong to the pinoid clade of the family Pinaceae. Intriguingly, Suillus sporocarps have been sporadically collected in forests in which known hosts from these genera are locally absent. To determine the capacity of Suillus to associate with alternative hosts in both the pinoid and abietoid clades of Pinaceae, we examined the host associations of two Suillus species (S. punctatipes and S. glandulosus) through field-based root tip sampling and seedling bioassays. Root tip collections underneath Suillus sporocarps were molecularly identified (fungi: nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 [ITS barcode]; plant: trnL) to assess the association with multiple hosts. The bioassays contained both single- and two-species treatments, including a primary (Larix or Pseudotsuga) and a secondary (Picea, Pinus, or Abies) host. For the S. punctatipes bioassay, an additional treatment in which the primary host was removed after 8 mo was included to assess the effect of primary host presence on longer-term ECM colonization. The field-based results confirmed that Suillus fungi were able to associate with Abies and Tsuga hosts, representing novel host genera for this genus. In the bioassays, colonization on the primary hosts was detected in both single- and two-species treatments, but no colonization was present when Picea and Abies hosts were grown alone. Removal of a primary host had no effect on percent ECM colonization, suggesting that primary hosts are not necessary for sustaining Suillus colonization once they are successfully established on secondary hosts. Collectively, our results indicate that host specificity is more flexible in this genus than previously acknowledged and help to explain the presence of Suillus in forests where recognized hosts are not present. [ABSTRACT FROM AUTHOR]

In spite of silver fir (Abies alba Mill.) historical importance for forestry management in the Czech Republic, this species shares currently mere 1.1% in the Czech forests due to several reasons such as biotic agents, air-pollution, game damage, inappropriate silvicultural systems etc. According to frequent calamities in dominant spruce monocultures, silver fir has been planted increasingly to establish more diverse and structured stands in last decades. These new stands with silver fir should be also adequately thinned. We see, however, a lack of experience with this silvicultural measure in practice nowadays. The article brings review of results and knowledge about thinning of silver fir stands in the Czech Republic and also from abroad where similar conditions can be expected. It is obvious that silver fir requires different approach to thinning compared to other conifers. We summarised knowledge about measures applied in both fir monocultures and mixtures from young phase of regeneration (artificial or natural) to final thinning in mature stands. Recommendations for pruning and for stands with postponed thinning are also included. [ABSTRACT FROM AUTHOR]

This particular paper analyzes the age of fir (Abies alba Mill.), spruce (Picea abies Karst.) and beech (Fagus sylvatica L.) trees, with a diameter at breast height of approximately 50 cm (diametar classes 47.5 and 52.5 cm) in mixed uneven-aged multi-leyerd stands. Research data was obtained from four continuous experimental plots on Mt. Igman, with different site conditions and stand structure on which the selective management method is carried out. Based on the number of annual growth rings on the incerement cores to the center of the tree taken at a height of 1.3 m, the so-called “age of growth” was determined (Flury according to Stamenković, Vučković 1988). However, the actual age is greater than the determined age, for the time required to reach a height of 1.3 m. The research indicated that the tree age is of great variability. The range for fir trees is from 70 to 350 years, for spruce trees from 65 to 256 years and for beech trees from 113 to 275 years. Moreover, the research implicates that the differences in age between tree species within one stand aren’t statistically significant in all analyzed cases, while differences between trees of the same tree species from stands of different site and stand conditions are statistically significant. The differences between the observed fir and beech trees in the same stand are not statistically significant, while the differences between the trees of these tree species and spruce trees are statistically significant. For all observed tree species, it was found that the age of trees is on average lower in sites of medium quality, compared to sites of better and lower quality. It was concluded that differences in the age of observed trees are determined by tree species, site conditions and stand structure (competitive relations) and other factors not covered by this study, and that the age of trees of certain species to some extent indicates the production potential of sites. [ABSTRACT FROM AUTHOR]

Tree bark is rich in commercially valuable secondary metabolites such as polyphenolic compounds like flavonoids and tannins. The yield and composition of bark extractives from Abies alba varies longitudinally within the stem. A. alba bark above the crown had the greatest extractive content, but the concentration of polyphenolic compounds was greatest below the crown. Here, we use a nonlinear model describing how bark extractive yields of A. alba , Picea abies and Pseudotsuga menziesii change with height, where differences among species are accounted for using different model coefficients. For all species there is longitudinal variability in extract yield. For P. abies and P. menziesii , the form of that variation differs depending on whether the bark was located at the same position in the stem as branches. Although the relationship form of total extractive yield differs between branched and un-branched samples, the relationship forms for individual compound yields does not change depending on branch presence. Despite trees from thinned stands having longer crowns and faster growth rates, indicative of greater photosynthetic activity, there was no evidence that thinning had affected either the yield or composition of extractives in these species. In P. abies , the proportions of flavonoids was higher in bark from the top of the tree, whereas epi-gallocatechin gallate was found in high proportions at the stem base. In P. menziesii bark extracts, taxifolin was the dominant compound, present in significantly higher proportions in bark towards the base of the stem. Image 1 • Softwood bark extractive yields are higher at the top of the tree. • Thinning does not affect extractive yields, but branch presence does. • Sample height influences compositions, possibly through influencing synthesis. • Flavonoids augment with height in Picea abies extracts. • Taxifolin is abundant in lower bark extracts of Pseudotsuga menziesii. [ABSTRACT FROM AUTHOR]

• Hybrid firs embryogenic tissue was cultured on medium supplemented with Cd ions. • The cultures accumulated cadmium ions with negative effect on the growth. • The toxic effect of cadmium was also apparent on the structure of somatic embryos. • The increased malondialdehyde content in response to Cd indicated lipid peroxidation. The study was focused on the investigation of cadmium (Cd) effect on the embryogenic tissue of hybrid firs growing under in vitro conditions. Two cell lines AC78 (Abies alba x A. cephalonica) and AN72 (Abies alba x A. numidica) were cultured on DCR medium supplemented with 100 and 250 µM of Cd(NO 3) 2 ·4H 2 O. The tissue accumulated heavy metal ions during the culture period and at the end of growth cycle 91.4% of Cd2+ present in the medium was accumulated in AN72 and 94.6% in cell line AC78. Higher concentration of Cd2+ affected negatively the growth of tissue exerted as decline in fresh as well as dry mass accumulation, although in comparison to control tissue statistically significant reduction has been recorded only for cell line AN72. The toxic effect of cadmium was also apparent on the micromorphology of early somatic embryos and resulted in loss of bipolarity as well as complete structural disintegration. The increased malondialdehyde content in response to Cd2+ in culture medium indicated lipid peroxidation as a consequence of membrane damage. The embryogenic tissue is suitable experimental system for the study of cadmium effect on the cells cultured in extremly controlled environment in vitro. [ABSTRACT FROM AUTHOR]

Biogradska Gora National Park in Montenegro is part of the Bjelasica Mountain which belongs to the montane region of the Dinaric Alps. Biogradska Gora is one of the largest long-term preserved forests in the Southeast Europe. In this paper there were compared the main structural characteristics of the old-growth mixed forest of spruce (Picea abies L.), fir (Abies alba L.) and beech (Fagus moesiaca (Domin, Maly) Czecz.), from the preserved area of the Biogradska Gora, with similar managed forests from the same mountain. Basic insight into the structural characteristics of forests of spruce, fir and beech was obtained by analyzing tree species composition and two basic structural elements - number of trees and wood volume per unit area. The obtained data provides overview of the structural characteristics of these forests. The results revealed the production potential of the studied mixed forests. The average quantity of standing volume in old-growth forests of Biogradska Gora indicates very valuable and productive forest ecosystems. Presented data shows that forest ecosystems of spruce, fir and beech in the protected area of the National Park Biogradska Gora are characterized by structurally irregular forests with presence of old trees with relevant growing stock and optimal balance of beech and conifer species, while in managed forests on the same mountain, growing stock is very low and with structure which is far from optimal. [ABSTRACT FROM AUTHOR]

In Europe, mixed mountain forests, primarily comprised of Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.), and European beech (Fagus sylvatica L.), cover about 10 × 106 ha at elevations between ∼600 and 1600 m a.s.l. These forests provide invaluable ecosystem services. However, the growth of these forests and the competition among their main species are expected to be strongly affected by climate warming. In this study, we analyzed the growth development of spruce, fir, and beech in moist mixed mountain forests in Europe over the last 300 years. Based on tree-ring analyses on long-term observational plots, we found for all three species (i) a nondecelerating, linear diameter growth trend spanning more than 300 years; (ii) increased growth levels and trends, the latter being particularly pronounced for fir and beech; and (iii) an elevation-dependent change of fir and beech growth. Whereas in the past, the growth was highest at lower elevations, today's growth is superior at higher elevations. This spatiotemporal pattern indicates significant changes in the growth and interspecific competition at the expense of spruce in mixed mountain forests. We discuss possible causes, consequences, and silvicultural implications of these distinct growth changes in mixed mountain forests. [ABSTRACT FROM AUTHOR]

From the immemorial time wood is highly abundant and well-performing material. Further one due to practical use the wood heat treatment, as a process for improving its properties has been enhanced in the recent tim. Abies alba Mill and Acer campestre L. are among the most wide spread species in Albanian forest and among the most useful types of wood in Albanian wood industry. The objective of this study is to investigate the influence of short time heat treatment on dimensional stability and the mass loss of these two species. Wood samples are treated in three different temperatures (180 ℃, 200 ℃, 220 ℃) and two different time durations of 15 and 30 minutes. After the heat treatment, the mass loss is determined for treated samples. Treated and untreated samples are immersed in water and the swelling is determined. According to the results obtained, wood swelling undergoes a considerable reduction in the case of wood treatment at a temperature of 220 ℃ for the longest time duration of 30 minutes. The higher percentage of weight loss after the thermal treatment (9.66% for the maple and 10.77% for the fir) was measured in the samples treated in a 220 ℃ for 30 minutes. The results of both treated and untreated wood were given for comparative purposes. [ABSTRACT FROM AUTHOR]

Furniture design has changed from traditional to new, original and practical ones. Creation of new furniture design is a challenge. Furniture is not only a part of the interior design but it also should offer comfort, flexibility, functionality and aesthetic appeal. The paper presents an original piece of furniture based on Lego concept. It is made of fir (Abies Alba L.) wood block units assembled by dowels. The furniture structure is designed in such a way that from the basic piece (the table) by combining the component blocks (the cubes and rectangular parallelepipeds) and the plates (superior, inferior) and lateral walls it can be achieved pieces of small furniture like stool, benches and a storage box. The manufacturing steps are also presented and by using imagination and creativity other different pieces of furniture could be made, just play with. [ABSTRACT FROM AUTHOR]

• Conversion of formerly spruce-dominated stands at their distribution margin. • Analysis of management and microsite effects on regeneration success. • High regeneration potential in mixed forests at their south-eastern limits. • Single-tree selection cuttings favour fir recruitment at the expense of spruce. • Ungulates played a negligible role in tree recruitment processes. Mixed mountain forests consisting of Norway spruce (Picea abies (L.) Karst.), European beech (Fagus sylvatica L.), and silver fir (Abies alba Mill.) are among the most productive and stable forest ecosystems in Europe. Their southeasternmost geographical distribution range is located in the Western Rhodopes, where they have high economic, recreational, and ecological value. In the past, shelterwood cuttings dominated forest management practices in these forests and were mainly aimed at maintaining and reproducing conifers. During the past two decades, single-tree and group-tree selection systems have been promoted as alternative management approaches to support the conversion of spruce-dominated stands to close-to-nature mixed forests of fir, beech, and spruce. However, the natural regeneration dynamics in these stands are barely known, and their dependence on microsite and management effects needs to be better understood. The objective of this study was to investigate ecological factors under management regimes of different intensity ("single-tree"-selection and "group-tree"-selection) that influence the regeneration processes in mixed mountain forests in the Bulgarian Rhodopes. Data on regeneration and microsite conditions were collected on 105 systematically distributed plots (25 m2/100 m2) in four 100–120 years old stands located in the regional forest district of Smoljan, Bulgaria (1580–1650 m a.s.l.). We relied on generalizeds linear mixed models to analyse for each species the (1) size-dependent regeneration density and (2) height increment in dependence on management practices, competing vegetation, as well as soil and light conditions. Our study revealed an overall high potential for recruitment in the Western Rhodopes. Regeneration density was highest in fir (median 12800 N ha-1), followed by spruce (median 1600 N ha-1) and beech (median 1200 N ha-1). Fir benefited most from "single-tree" selection cuttings, while "group-tree" selection cutting tended to promote beech and fir but also spruce. Competing ground vegetation was detrimental for seedling density of all species. Annual height increment increased with plant size, was lowest in spruce, and similar in fir and beech. Sapling increment was driven by light, whereas seedlings did not react to increased radiation. Browsing was species-specific and was highest in beech (15–30 %), followed by fir (5–10 %) and spruce (<1 %). It was not a crucial factor in impeding tree recruitment. We conclude that frequent harvest activities of low intensity which consider advanced regeneration are a promising approach to successfully convert the formerly spruce-fir-dominated forests to climate-adapted fir-beech-(spruce)-mixed stands. [ABSTRACT FROM AUTHOR]

• The deadwood is a good alternative to soil for the growth of a new generation of fir. • The deadwood contained much less aluminium than the soil. • Lying logs of deadwood create a valuable microhabitat. Deadwood plays multiple important roles within forest ecosystems. In the context of climate change, more frequent disturbances (windbreaks, droughts, etc.) will increase the quantity of dead trees. Researching deadwood and its effects on the growth and regeneration of a new generation of trees is therefore justified. Our aim was to elucidate whether the decay of wood could be as beneficial as soil to the growth of young trees. We determined the degree of nutrition of silver fir seedlings growing on soil and deadwood, as well as the morphological features of the above- and belowground parts of seedlings developing on these substrates. The study confirmed our supposition that deadwood in the fifth decomposition distribution might be as effective a substrate for the growth of fir seedlings as soil. Besides aluminium content, no differences were detected in seedlings' micro- and macronutrient content. Furthermore, we found that the deadwood contained much less aluminium than the soil, which translated into the content of this component in the needles. Our study shows that deadwood can prove a better substrate for the growth of simple seedlings compared to highly acidic soils, due to its resistance to aluminium toxicity. Lying logs of deadwood create a valuable microhabitat with favourable abiotic conditions, providing young seedlings with suitable growth conditions. [ABSTRACT FROM AUTHOR]

Drought periods are becoming more frequent and intense, due to the effects of climate change, threatening natural habitats worldwide, including European forests. Forest trees can also be affected by high soil salinity, because of the common practice of de-icing of mountain roads with NaCl in winter. We have evaluated the responses to salt and water stress of silver fir (Abies alba), an important forest species for which very limited information is available. One-year-old fir seedlings, with origin in seven different locations in Romania, were subjected to salt (watering with NaCl solutions of increasing concentrations) and water deficit (complete withholding of irrigation) treatments in the greenhouse. After one month, plant material was harvested and different morphological parameters were determined in the stressed and control plants. Both stress treatments inhibited growth of fir seedlings from all seven provenances, although quantitative differences in the responses to stress were observed between populations. Growth inhibition was established by the relative reduction - as compared to the non-stressed controls - in several parameters, such as stem elongation, root length, number of needles, or fresh weight and water content of roots and needles. Statistical multivariate analysis of the results suggested that seedlings from Valea Morii (population 6) were the most tolerant to both, water deficit and high (300 mM NaCl) salt concentrations. These results support the possibility to screen a large number of individuals from different populations, at the seedling stage, to select Abies alba genotypes with enhanced drought and/or salinity tolerance. [ABSTRACT FROM AUTHOR]

There is a limited understanding of the impacts of global warming on intra- and interspecific plant competition. Resolving this knowledge gap is important for predicting the potential influence of global warming on forests, particularly on high-altitude trees, which are more sensitive to warming. In the present study, effects of intra- and interspecific competition on plant growth and associated physiological, structural and chemical traits were investigated in Abies faxoniana and Picea purpurea seedlings under control (ambient temperature) and elevated temperature (ET, 2 °C above ambient temperature) conditions for 2 years. We found that A. faxoniana and P. purpurea grown under intra- and interspecific competition showed significant differences in dry matter accumulation (DMA), photosynthetic capacity, nutrient absorption, non-structural carbohydrate (NSC) contents and leaf ultrastructure under ET conditions. ET increased leaf, stem and root DMA of both conifers under both competition patterns. Moreover, under ET and interspecific competition, P. purpurea had overall superior competitive capacity characterized by higher organ (leaf, stem and root) and total DMA, height growth rate, net photosynthetic rate, specific leaf area, water use efficiency (δ13C), leaf and root N and NSC concentrations and greater plasticity for absorption of different soil N forms. Thus, the growth of P. purpurea benefitted from the presence of A. faxoniana under ET. Our results demonstrated that ET significantly affects the asymmetric competition patterns in subalpine conifer species. Potential alteration of plant competitive interactions by global warming can influence the composition, structure and functioning of subalpine coniferous forests. [ABSTRACT FROM AUTHOR]

• A. fabri had greater SLA, leaf N and P contents, and N absorption than P. brachytyla. • P fertilization lowered SRL and ectomycorrhizal infection in two coniferous species. • A. fabri had superior performance of above-ground traits in response to added P. • A. fabri had greater competitive capacity than P. brachytyla under P fertilization. Leaf and root systems are known to show a high degree of developmental plasticity in response to the local environment. However, few studies have investigated simultaneously the leaf and root traits as affected by competition and phosphorus (P) fertilization, especially in connection with the primary succession. We investigated morphological and physiological responses to different competition treatments (intra- vs. interspecific competition) and P regimes in seedlings of Abies fabri and Picea brachytyla , collected from the late succession stage Hailuogou glacier retreat area. A. fabri had a greater total chlorophyll content and specific leaf area (SLA), higher leaf nitrogen (N) and P concentrations, as well as a higher water use efficiency (assessed by the carbon isotope composition, δ 13C) and N absorption relative to P. brachytyla under P fertilization conditions, and its total biomass responded more strongly to P fertilization, especially under interspecific competition. P fertilization decreased the specific root length (SRL) and ectomycorrhizal infection in both species and specific root tip density in P. brachytyla but it had no effect on the average root diameter. We concluded that similar changes in root characteristics, but the superior performance of above-ground traits in A. fabri in response to P availability, especially under competition, explain the greater competitive capacity of A. fabri at final stages of succession. These findings highlight the influence of soil nutrition availability and competition on the functional traits of plants and contribute to the understanding of the role of relative modifications in leaf and root traits during succession. [ABSTRACT FROM AUTHOR]

Abies and Nepeta species are well known for their traditional use in traditional medicine from Bukovina, Romania, and other parts from the world. However, too few studies present the connection between phenophase, chlorophyll content and antioxidant activity of extracts obtained from medicinal plants. Phenophases, like stages from vital cycle of plants, involve seasonal and evolutionary changes, including chlorophyll content of the leaves. With these changes, there are also changes in the oxidative activity of the extracts obtained from the studied plants. The chlorophyll was extracted with acetone, being quantitatively measured using the spectrophotometer. Antioxidant activity was determined by the DPPH method. This method is one from the most popular ways to measure the antioxidant capacity of a substance. The studied species are Abies alba and Nepeta pannonica. Plants were harvested from different locations of Bukovina, from areas of Câmpulung Moldovenesc and Cacica localities, Suceava county, Romania. Chosen phenophases were growing and flowering. The DPPH method implies making some extracts with organic solvents from collected plants, in this case being acetone. Using 2,2-diphenyl-1-picrylhydrazil reactive, there was determined the antioxidant capacity of mentioned extracts. There were observed variations of this depending of phenophase and collecting areas, being closely related to total chlorophyll content. The both species have behaved differently and obtained results can be used to determine the optimal harvest moments of these plants. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the sensitivity of silver fir (Abies alba Mill.) from the Rudnik Forest District on the selected meteorological elements and to develop a chronology of local tree-ring width and the annual sensitivity. Based on the analysis, the site chronology of silver fir was developed and the strength of the relationship between the climate components and the width of annual rings was calculated. In addition, we examined the degree of homogeneity of short-term incremental response, rated the representativeness of the chronology and climate signal strength. Having analysed the indicator years, namely 1932–2013, we concluded that the growth of firs was positively influenced mainly by air temperature in winter, and to a lesser extent, by precipitation in spring and summer. The main factors that limit its growth are cold winters, cool and low rainfall summers, and rainy springs. [ABSTRACT FROM AUTHOR]

The paper deals wiThevaluation of silver fir growThin the four experimental plots situated in more-less monospecific or mixed spruce, fir and beech stands in Slovakia. No interventions on the mentioned plots were carried out for the investigated period of 45 to 50 years. Comparison of height growThcourse and selected quantitative characteristics (current annual basal area increment, relation between current annual diameter increment and crown width) were found. The results showed substantial decrease of silver fir from 7% to 30% out of total basal area, whereas original proportion was found 21-51%. On the contrary, the highest share was registered on all plots for beech. Actually, on pure fir stand the proportion of this species increased during the investigated period. On the mentioned stand, the best height growThwas found in a consequence of the best site index, as well as the highest values of crown widThand basal area increment. The closest relation between crown widThand annual diameter increment was found on plots wiThthe lowest number of trees. Results suggested that fir proportion and its growThin mixed stands wiThspruce and beech was markedly influenced by the latter tree species, which is considered to be a strong competitor under the given ecological conditions.` [ABSTRACT FROM AUTHOR]