Picea Abies Research Articles

Gene expression plasticity facilitates different host feeding in Ips sexdentatus (Coleoptera: Curculionidae: Scolytinae)

Host shift is ecologically advantageous and a crucial driver for herbivore insect speciation. Insects on the non-native host obtain enemy-free space and confront reduced competition, but they must adapt to survive. Such signatures of adaptations can often be detected at the gene expression level. It is astonishing how bark beetles cope with distinct chemical environments while feeding on various conifers. Hence, we aim to disentangle the six-toothed bark beetle (Ips sexdentatus) response against two different conifer defences upon host shift (Scots pine to Norway spruce). We conducted bioassay and metabolomic analysis followed by RNA-seq experiments to comprehend the beetle’s ability to surpass two different terpene-based conifer defence systems. Beetle growth rate and fecundity were increased when reared exclusively on spruce logs (alternative host) compared to pine logs (native host). Comparative gene expression analysis identified differentially expressed genes (DEGs) related to digestion, detoxification, transporter activity, growth, signalling, and stress response in the spruce-feeding beetle gut. Transporter genes were highly abundant during spruce feeding, suggesting they could play a role in pumping a wide variety of endogenous and xenobiotic compounds or allelochemicals out. Trehalose transporter (TRET) is also up-regulated in the spruce-fed beetle gut to maintain homeostasis and stress tolerance. RT-qPCR and enzymatic assays further corroborated some of our findings. Taken together, the transcriptional plasticity of key physiological genes plays a crucial role after the host shift and provides vital clues for the adaptive potential of bark beetles on different conifer hosts.

Field effects of oxygenated monoterpenes and estragole combined with pheromone on attraction of Ips typographus and its natural enemies

IntroductionCentral European Norway spruce monocultures face Ips typographus outbreaks due to decreasing resistance. These beetles use volatile compounds to communicate and select suitable host trees. Spruce trees, beetles, and their symbiotic ophiostomatoid fungi emit oxygenated monoterpenes, including 1,8-cineole, α-terpineol, camphor, carvone, terpinen-4-ol, isopinocamphone, and pinocamphone, and the phenylpropanoid estragole, particularly in the infestation phase. These compounds trigger strong responses in I. typographus antennae, motivating our field study.ObjectiveThis study aimed to assess how adding these compounds to the aggregation pheromone of Ips typographus modulates the attraction of this bark beetle and its natural enemies.MethodsIn combination with I. typographus pheromone, estragole, 1,8-cineole, (±)-camphor, (–)-carvone, alpha-terpineol, (–)-terpinen-4-ol, (+)-pinocamphone, and (+)-isopinocamphone at low, medium, and high doses were tested in pheromone traps at two sites in the Czech Republic.ResultsAll 1,8-cineole doses and the high estragole dose acted as anti-attractants for I. typographus, whereas all (+)-isopinocamphone doses enhanced their attraction to pheromone. Catches of natural enemies, the Staphylinidae and Pteromalidae, varied by location.Conclusion1,8-cineole, isopinocamphone, and estragole may play vital roles in tritrophic interactions among spruce trees, and I. typographus and its natural enemies, and these compounds may be developed into new or enhanced semiochemical-based pest control methods.

Mechanical Performance of Heat-Treated Norway Spruce (Picea abies) Wood

In this study, the mechanical characteristics of Norway spruce wood (Picea abies) from Bosnia and Herzegovina were investigated by thermal treatment at three different temperatures (specifically, 180, 190, and 210°C) and treatment durations (namely, 2, 3, and 4 hours). For this purpose, the maximum 4-point bending force, the modulus of elasticity in bending, the compression strength parallel to the grain, and the compression strength perpendicular to the grain in treated and untreated specimens were evaluated. Results indicated that the relationship between temperature and duration modification affects the mechanical properties of wood specimens. The results revealed that the relationship between temperature and duration modification influenced the mechanical properties of the wood samples. Specifically, in terms of compression strength, it was observed that the heat-treated specimens exhibited improved mechanical properties compared to the unmodified specimens. However, for the maximum 4-point bending force and modulus of elasticity, the results indicated a decrease in mechanical properties.

Pilot Study of 3D Spatial Distribution of α-Pinene Emitted by Norway Spruce (L.) Karst Recently Infested by Ips typographus (L. 1758) (Coleoptera: Scolytinae)

The Eurasian Spruce Bark Beetle (Ips typographus) (L. 1758) (Coleoptera: Scolytinae) poses a significant threat to Eurasia’s Norway spruce (Picea abies) (L.) Karst, forests. Early detection of infested trees is crucial to control beetle outbreaks and allow salvage logging before the next generation emerges. Besides traditional methods, new approaches focus on monitoring volatile organic compounds, mainly monoterpenes, emitted by infested trees. Using analytical chemistry, we studied the distribution of these compounds, particularly α-pinene, around infested trees. In lab trials, we optimized α-pinene detection using dynamic absorption and solid-phase microextraction (SPME), analyzed by gas chromatography with flame ionization detection (GC-FID). We conducted forest trials, revealing varying α-pinene abundance due to changing conditions. However, consistent trends emerged: levels were highest near the infested tree stem and 1.3 m above ground in the first trial and at a 1 m distance from the infested stem in the second. We generated a three-dimensional cloud depicting the distribution of α-pinene around infested trees in their natural habitat. These findings open avenues for detecting bark beetles on a large scale by mapping elevated concentrations of volatile organic compounds emitted by infested trees, potentially leading to alternative pest management methods. Scanning methods, such as electronic sensors combined with remote sensing, hold promise for this application.

Wood Colouring with Natural Dye Extracts. New Research and Perspectives

The aims of the present research were to test new types of natural dye extracts for wood as a possible alternative to synthetic dyes and to evaluate the colour changes after a period of one year of exposure to natural light, in indoor conditions. Three types of extracts using raw materials: nutshell from Juglans regia L. (E1), onion peels (E2), and dry plant of Chelidonium majus L. (E3) were employed. Spruce wood (Picea abies L. Karst) samples with dimensions of (120x80x5) mm were used. The dye aqueous solutions with a concentration of 5% (E1, E3) and 2.5% (E2) were obtained by solid-liquid extraction at 100°C for three hours. The extracts E1, E2, E3 were modified by the addition of mordant ferrous sulphate Fe2(SO4)3 3% and coded EM1, EM2, EM3 respectively. The wood was coloured by dipping procedure at 60° C for 30 min. Three replicates were employed for each type of dye solution. After conditioning, two replicates together with the uncoloured samples (M) were further exposed indoors, and one coloured sample remained unexposed, as a control. Colour measurements in the CIELab system were performed before and after each period of exposure (30, 60, and 365 days), and the colour differences ΔL, Δa, Δb, and ΔE were calculated. Generally, all the samples dyed with natural extracts had fewer colour differences compared with the uncoloured wood. The lower value for colour change was registered for the E2 extract, followed by the E3, and E1 extract, respectively. According to the exposure time, the colour differences values ΔE range correspond to a medium colour up to different colours in visual perception. For mordant dye extracts EM1, EM2, and EM3 the results indicated a different colour in visual perception. The ΔE values registered were even higher than the uncoloured samples (M). The results were in accordance with similar research in the field. The present study opens new research opportunities in wood finishing and new colouring perspectives with eco-friendly dyes.

Evaluating Pfeiffer Circular Chromatography as a Qualitative Methodology of Viscum album Homeopathic Mother Tinctures: A Multicentric Collaborative Project Between Brazil and Switzerland

Viscum album (VA) is a peculiar semiparasitic plant with important role in cancer therapy. The differences in phytochemical composition as well as the influence of host tree in the metabolome of VA subspecies are already described1. Our goal is to use the Pfeiffer Circular Chromatography (PCC) as a qualitative methodology to differentiate V. album mother tinctures (VAMT). The assays were conducted in two countries: Brazil (São Paulo and Rio de Janeiro) and Switzerland (Arlesheim). Three VA subspecies (abietis, album, austriacum) and five host trees (Malus domestica, Quercus sp., Ulmus carpinifolia, Pinus sylvestris, Abies alba) were harvested in Switzerland in summer and winter. The VAMTs were prepared following the Brazilian Homeopathic Pharmacopoeia and the PCC experiments were performed as previously published2. The preliminary analysis and the reproducibility of the three independent assays performed in each experimental set are being evaluated by Image J software. The qualitative standard features will be used to the VAMT differentiation regarding the following PCC characteristics: inner and outer-zones, coloration, size, the presence of radial lines, among others. Besides, the High-Performance Thin Layer Chromatography (HPTLC) was performed as standard quality control methodology using the CAMAG instruments to compare the phytochemical profile of V. album mother tinctures described in the French and German Homeopathic Pharmacopoeias. The samples have been characterized by the compounds retention factor (Rf) compared to the chemical standards (chlorogenic acid, caffeic acid, hyperoside and rutin). They present similar chemical markers when both methodologies were compared but with different intensities between season and host trees. Based on the hypothesis that the PCC patterns could be correlated with the chemical composition of VAMT, this multicentric research project will be useful to propose a low-cost and an easy methodology focused on the quality control parameters of these herbal raw materials.

Multi-year evapotranspiration estimates from four common vegetation types in a montane region of the intermountain west

Evapotranspiration (ET) is a major component of water balance and is crucial for understanding the hydrological processes, however due to highly heterogeneous distributions of soils and plants, accurate quantification of ET remains a major challenge in montane ecosystems. In this study, water use for four common vegetation communities was numerically modeled using Hydrus-1D over four continuous growing seasons (2009 to 2012), supported by a network of soil water content sensor measurements. Plant species included i) aspen (Populus tremuloides) with understory dominated by grass/forb (rudbeckia occidentalis, Bromus carinatus and Elymus trachycaulu), ii) conifer (Picea engelmannii and Abies lasiocarpa), iii) grass (dominated by B. carinatus and E. trachycaulu, et al.), and iv) sage (Artemisia tridentata). The numerical model simulated water transport within the soil and water loss from soil evaporation and plant transpiration processes. Simulations were compared with temporal and spatial dynamics of soil water content, measured at 0.1 m, 0.25 m and 0.5 m within each of 36 subplots at 30-minute intervals. Numerically simulated ET in the sage/grass meadow was compared with ET determined from a centrally-located eddy covariance tower. The simulations effectively predicted soil moisture and ET of the montane plant communities during summer dry down. Results indicate vegetation type showed no significant difference (<5 %) in ET comparing four growing seasons, except where abnormally wet conditions occurred. Four-year mean cumulative growing season ET estimates for aspen, deep-rooted conifer, shallow rooted conifer, sage, and grass were 43.0, 40.2, 28.7, 28.8 and 26.1 cm, respectively.

The Environmental and Genetic Controls of Increment Suggest a Limited Adaptability of Native Populations of Norway Spruce to Weather Extremes

In the Baltics, warming is expected to burden the growth of Norway spruce Picea abies, with weather anomalies/extremes having strong triggering effects, which can be mitigated by tree breeding. Within the region, breeding programmes have been aiming for productivity, yet being conservative, their sustainability depends on the adaptability of native genotypes, which is unclear. The adaptability of genotypes can be assessed through local adaptations and phenotypic plasticity, with the sensitivity of increment depicting the conformity of genotypes and environments. To assess the adaptability of native populations to anticipated climates, local genetic adaptation and phenotypic plasticity of the weather sensitivity of the radial increment were assessed by the methods of time series analysis and quantitative genetics based on three clonal trials (low-density single-tree plot plantations of grafted clones of native plus trees) representing the local climatic gradient in Latvia. The growth of trees was sensitive to the moisture availability in summer and the thermal regime in winter, yet coinciding anomalies in both were associated with abrupt changes in tree ring width. These environmental effects differed among the clones, indicating genetic controls over the sensitivity of increment, which, however, decreased under a warmer climate, suggesting a limited adaptability of local populations to warming. Still, the weather-growth relationships showed moderate phenotypic plasticity, suggesting some mid-term adaptability. Accordingly, supplementation of breeding populations via assisted gene transfer with the genotypes that are adapted to warmer and drier climates appears crucial.

Biological effects of Viscum album homeopathic preparations in kidney proximal tubule cells: an in vitro study

Viscum album (VA) preparations of different host trees have been used for the treatment of different diseases with mainly on cancer1 and cardiovascular diseases2. However, the mechanisms related to the mistletoe hypotensive potential are poorly investigated. Therefore, the objective of this work was to evaluate the cytotoxicity, the Na+/K+ ATPase activity and the Reactive Oxygen Species (ROS) generation induced by winter and summer Viscum album mother tinctures (TMVA), as well as by their potentized samples (6cH, 12cH and 30cH), in porcine proximal tubule renal cells (LLC-PK1). For the cytotoxicity evaluation, after 24h of treatment with TMVA (from Quercus robur, Malus domestica, Ulmus carpinifolia, Pinus sylvestris and Abies alba), at concentrations ranging from 0.5% to 2.5% (V/V), the 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) was added. The same procedure was done with the potentized samples, after systematic control evaluation, in which the dynamized water was blindly tested. For the Na+/K+ ATPase and ROS assays, cells were treated only for 30 min, using 1.5% (V/V) of TMVA of Malus domestica, Pinus sylvestris, and Abies alba and their respective homeopathic potencies. The MTT assay showed a dose-dependent cytotoxicity related only to the summer Quercus Robur TMVA (p&lt;0.05). Since for the enzymatic and ROS assays cells need to be metabolically active, this TMVA was excluded from these experimental evaluations. Regarding the ROS generation (n=5), no significant effects were triggered neither by TMVA nor by the potentized samples (p&gt;0.05). The Na+/K+ ATPase evaluation (n=9) indicated no enzymatic activity alterations at 30min of incubation time. Further experiments are under development with higher incubation cellular times (24 and 48 h) to confirm the Na+/K+ ATPase effects induced by potentized and non-potentized V. album samples. Additionally, the gene expression of Na+/K+ ATPase, by western blot, and the ultrastructural cellular aspects, using transmission electron microscopy, will be performed.

Treatment with Viscum album potencies induces reduction of MCP-1 and ROs levels in murine melanoma cells.

Melanoma is responsible for most skin cancer deaths. It has a high metastatic potential, complex treatment, and a hopeless prognosis. Viscum album extract (Va) is a complementary treatment in cancer, with in vitro and in vivo cytotoxic effects on different tumor types. However, its ultra-diluted homeopathic preparations' effects and mechanisms on cancer cells need further study. Thus, the aim of present work was to investigate cytokine profile and ROs production of melanoma cells after treatment with ultradiluted VA collected from host tree Abies alba (VaAa) and Quercus rubur (VaQr)during Swiss summer. For this, potencies of Va in different homeopathic scales were prepared using mother tincture (MT) from VaAa and VaQr submitted to homeopathic ethanolic maceration and then a subsequent dynamization process. Then, B16F0 melanoma cells cultivated in 24-well plates were treated with MT or 12DH, 200CH or 5LM potencies of VaAa or VaQr for 24, 48 or 72 hours. After these periods, culture supernatants were collected to assess the levels of MCP-1, INF-γ, TNF-α, IL-10, IL-12p70 and IL-6 cytokines and, ROs production. Results demonstrated significant reduction of MCP-1 and ROs levels in B16F10 melanoma cells treated with Va (VaQr, preferentially) at 12DH or 5LM potencies when compared to untreated or carboplatin-treated cells. In conclusion, we demonstrated for the first time, the in vitro effects of Va potencies prepared in different homeopathic scales in relation to cytokines and ROs production in cell melanoma cells.

Potential implications of shortened rotation length for forest birds, bryophytes, lichens and vascular plants: An example from southern Swedish production forests

The rotation lengths of intensively managed production forests may be altered to achieve a variety of goals, with correspondingly implications for biodiversity. Here we consider the potential implications of shortened rotation times for biodiversity in planted monocultures of the two most common production tree species in Sweden, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). To do so we surveyed bird, bryophyte, epiphytic lichen and vascular plant diversity in 80 and 55-year-old stands; stand ages which approximate present-day and potential future rotation lengths in this region respectively. We found clear differences in the species communities of the 55 compared to the 80-year-old stands for both understory species and epiphytes, but not for birds. Nevertheless, bird species richness was still highest in the 80-year-old Norway spruce dominated stands. Dead wood amount was also highest the 80-year-old Norway spruce stands. Highest species richness of epiphytic lichens was found in 80-year-old Scots pine stands. However, 55-year-old Scots pine stands had a higher understory species richness and diversity than the older Scots pine stands, including a larger number of open land species. The 80-year-old forest stands examined may be considered old with respect to production forest rotation lengths in Sweden but are relatively young when comparing stand ages of unmanaged natural forest stands. Nevertheless, our results indicate that shortening the rotation time of Scots pine and Norway spruce, in this part of Sweden from 80 to 55 years, could have important consequences for forest biodiversity. These consequences are primarily inferred from the likely implications from shortened rotations for lichens community composition and diversity in both Norway spruce and Scots pine stands, as well as impacts on understory plant species in Norway spruce stands.

Utjecaj ekspozicije krošnje na morfološka svojstva iglica devet četinjača

The aim of this research was to investigate if the crown exposure of some conifers influenced to needle properties. The leaf morphological traits of sixty-six trees of nine conifers: Atlas cedar, Austrian pine, Blue spruce, Douglas fir, European spruce, European yew, Serbian spruce, Silver fir, and White fir, from six Belgrade parks, were analyzed. Five needles were measured from each of the four main crown exposures. Length, width, area and perimeter of needles were investigated. Species, parks in which they were found, as well as crown exposures, differed mostly in needle length and needle width. Correlations between measured needle traits were determined by linear regression analysis. Strong positive correlations were found between the length, perimeter, and area of needles. The differences among the species in terms of light requirement determine species for individual planting as light-loving or partial shade species (Atlas cedar, European spruce, Serbian spruce, Blue spruce, Austrian pine and Douglas fir), or for group planting as shade-loving species (Silver fir, White fir and European yew).

Quantifying the long-term recovery of the protective effect of forests against rockfall after stand-replacing disturbances

IntroductionIncreasing disturbances may significantly impact the long-term protective effect of forests against natural hazards. Quantifying the temporal development of the protective effect of forests is thus crucial for finding optimal management strategies.MethodsIn this study, we analyzed the long-term recovery of the protective effect of the secondary stands of spruce (Picea abies), fir (Abies alba), and beech (Fagus sylvatica) forests against rockfall after stand-replacing disturbances based on data of the Swiss National Forest Inventory (NFI). We therefore derived the age of the inventoried forest stands of those tree species based on a growth parametrization and quantified their energy dissipation capacity in rockfall processes as a function of stand age. We then analyzed the development of their protective factor for varying rockfall dispositions.ResultsGenerally, it takes between 50 and 200 years to regain the maximum possible protective effect, depending from the site conditions and the rockfall disposition. This implies that the recovery of the protective effect after a severe disturbance may require more time than the decay of the protective effect from disturbance legacies, resulting in a long lasting gap of the provided protection.DiscussionThe here presented approach can serve as a basis to estimate the general range of recovery of the protective effect of beech, fir and spruce forests against rockfall provided by forest stands. Future research should analyse the effects of environmental and forest conditions as well as varying disturbance intensities and legacies to enable the assessment of specific trajectories of the short- and long-term recovery of the protective effect.

Identification and high-throughput genotyping of single nucleotide polymorphism markers in a non-model conifer (Abies nordmanniana (Steven) Spach)

Single nucleotide polymorphism (SNP) markers are powerful tools for investigating population structures, linkage analysis, and genome-wide association studies, as well as for breeding and population management. The availability of SNP markers has been limited to the most commercially important timber species, primarily due to the cost of genome sequencing required for SNP discovery. In this study, a combination of reference-based and reference-free approaches were used to identify SNPs in Nordmann fir (Abies nordmanniana), a species previously lacking genomic sequence information. Using a combination of a genome assembly of the closely related Silver fir (Abies alba) species and a de novo assembly of low-copy regions of the Nordmann fir genome, we identified a high density of reliable SNPs. Reference-based approaches identified two million SNPs in common between the Silver fir genome and low-copy regions of Nordmann fir. A combination of one reference-free and two reference-based approaches identified 250 shared SNPs. A subset of 200 SNPs were used to genotype 342 individuals and thereby tested and validated in the context of identity analysis and/or clone identification. The tested SNPs successfully identified all ramets per clone and five mislabeled individuals via identity and genomic relatedness analysis. The identified SNPs will be used in ad hoc breeding of Nordmann fir in Denmark.

Models to predict the radial variation of stiffness, strength, and density in planted noble fir, Norway spruce, western hemlock, and western red cedar in Great Britain

Key messageThis 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.ContextTimber 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.AimsTo build empirical models for the radial variation in wood properties that can account for species.MethodsClear-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.ResultsThe 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.ConclusionAt 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.

Wood modification with trimethoxyphenylsilane via supercritical carbon dioxide for enhanced weathering resistance

Abstract This research focuses on increasing wood resistance against UV degradation using trimethoxyphenylsilane as modifying agent and supercritical CO2 as a green solvent and reaction medium. Trimethoxyphenylsilane was successfully grafted on European spruce (Picea abies, H. Karst) and was characterized by SEM-EDX and UV–vis reflectance. SEM-EDX showed the presence of silicium inside the wood cell wall. Increased wood moisture content showed positive effect on weight gain of trimethoxyphenylsilane after treatment. UV resistance of treated wood was evaluated by following the color change during artificial weathering. Modified samples showed improved weathering resistance compared to unmodified wood with a ΔE value around 5 after 260 h. Processing and modifying wood using supercritical CO2 is a promising route to increase wood performances and increase its use as a building material.

Anadolu sarıçamının (Pinus sylvestris L. var. sylvestris) doğal yayılış alanı ve vejetasyon bileşimi

Anatolian Scots pine (P. sylvestris var. sylvestris) forests spreading in the northern part of Anatolia, Türkiye, and covering 2.1 million hectares show great variation in terms of the vegetation composition depending on both ecological conditions and human interference. The spreading and/or growing of Scots pine is mostly related to the sunny cold, subhumid continental climatic conditions as well as the cold and semiarid climate. It begins at the coastal belt of the Black Sea coast and rises up to 2700 m in the NE part of Anatolia, and continues towards the semiarid continental part of Central Anatolia. Scots pine is associated with Fagus orientalis, Castanea sativa, Tilia rubra, T. tomentosa, Alnus barbata, A. glutinosa, Quercus sp., etc. in the lower belt of the Black Sea coast, with Picea orientalis and Abies nordmanniana in the eastern upper belt of the Black Sea Mountains, and with Abies bornmulleriana in the middle and western parts of the Black Sea Region. It is composed of Pinus nigra and A. nordmanniana subsp. equi-trojani in the backward or southern parts of the Black Sea Region. Pure Scots pine stands occur in the subhumid continental part of NE Anatolia and the semiarid-subhumid continental part of Inner Anatolia. This study aims to highlight the natural occurrence of its forests, and to introduce their main vegetation composition reflecting ecological conditions.

The response of forested upland micro-watersheds to extreme precipitation in a precipitation abundant year

We performed a comparative paired catchment study of three headwater upland forest micro-catchments with different forest types in the precipitation-abundant year 2020. The analysis was based on baseflow separation and resulting baseflow index (BFI). The year 2020 was intentionally chosen as a way to reflect the expected effects of climate change in the region where more extreme hydroclimatic events are expected. Our team demonstrated that in case of hydroclimatic extremes, there are significant differences in the runoff response from these catchments, depending especially on the tree species composition in the forest stands. Three forest types with the predominance of European beech (Fagus sylvatica), Norway spruce (Picea abies), and mixed forest were analyzed. The observed different values of BFI were interpreted in relation to the ability of forest stands to retain water and slow runoff in extreme runoff events determined by the stormflow component as an indication of their flood control efficiency. A significantly worse flood control efficiency and an overreaction of runoff response to precipitation events were observed in the spruce catchment. This also suggests that the spruce catchment is more prone to suffer from drought since twice as much water was lost from the system during extreme hydroclimatic events as opposed to the other two with less spruce in the stands and less water is thus available for groundwater recharge.

Winter warming response of gas-exchange and growth of Abies alba and Picea abies seedlings

Winter warming response of gas-exchange and growth of Abies alba and Picea abies seedlings

Picea pungens exhibits greatest tolerance to short-time thermal stress compared to Picea abies, and Picea omorika

Picea pungens exhibits greatest tolerance to short-time thermal stress compared to Picea abies, and Picea omorika