Search Results (53)

Insect assemblages associated with declining riparian black alder (Alnus glutinosa) stands were compared at the community level between two lowland river valleys in Poland that differ in anthropogenic transformation: the near-natural Łutownia River valley within the Białowieża Forest and the urbanised Utrata River valley in the Warsaw metropolitan area. Insects were sampled using active hand sampling and Barber pitfall trapping along a short-distance gradient from the channel during repeated monthly field campaigns in summer and early autumn. The near-natural valley supported a richer assemblage, with a stronger representation of forest-associated, saproxylic and aquatic taxa, whereas assemblages in Utrata contained a higher proportion of widespread disturbance-tolerant taxa. In both valleys, diversity was highest at an intermediate distance from the channel margin, and the between-valley contrast was more pronounced than the within-season shifts visible in the campaign summaries. The results identify a clear assemblage contrast between the two valleys, a consistent intermediate-distance diversity maximum, and only modest within-season variation in pooled campaign totals. These findings indicate that structurally complex riparian alder forests with retained dead wood are associated with richer and more taxonomically varied insect assemblages; microhabitat-related interpretations are retained as cautious sampling-point-scale associations because tree-level attributes and individual microhabitat categories were not quantified separately. Full article

This study assessed phenotypic variation among open-pollinated half-sib families from a single relict population. Autochthonous silver fir (Abies alba Mill.) preserved in the Tisovik Reserve of Białowieża Forest represents the northeasternmost isolated relict population of the species in Europe. To secure its genetic resources and evaluate its breeding potential, a conservation plantation of open-pollinated half-sib families was established in the Hajnówka Forest District outside the natural species range. This study assessed the effects of half-sib family affiliation on the growth and phenotypic performance of almost two thousand 28–31-year-old trees representing 20 half-sib families and compared them with age-matched managed stands in the State Forests of Poland. Significant within- and among-family variation was observed for diameter at breast height (DBH) and height (H), while environmental factors had only marginal influence under the uniform site conditions of the plantation. Several half-sib families produced disproportionately high numbers of individuals with exceptional phenotypic performance, including DBH values exceeding 25 cm and height values surpassing those of managed stands. Based on a combined assessment of qualitative traits, selection differential, and 95th percentile values, 30 prototype plus trees were selected as sources of scions for establishing a future seed orchard. The outstanding growth parameters of these individuals correspond to stand ages of 40–65 years according to yield tables, despite their biological age of only 28–31 years. The results confirm the high breeding value and substantial genetic variability of the Tisovik population and demonstrate its potential for producing genetically diverse planting material adapted to lowland sites under changing climatic conditions. Full article

Norway spruce (Picea abies (L.) Karst.) is experiencing large-scale decline across Central Europe, with climate warming and bark beetle (Ips typographus L.) outbreaks as primary drivers. In lowland Białowieża Forest, Poland, spruce occupies a range of habitats that differ in their suitability for long-term persistence. We hypothesized that climate change accelerates spruce decline by reducing resilience in suboptimal habitats and increasing susceptibility to bark beetle outbreaks, with long-term persistence limited to optimal hydrological sites. To address this, we analysed spruce share from 1902–2018, its distribution across suitable versus unsuitable habitats, and long-term climate records in relation to outbreaks. Historical maps, forest site classifications, and meteorological data were used to calculate hydro-climatic indices (HTC, SPEI-12, Selyaninov), and outbreak relationships were tested using Welch’s t-test and point-biserial correlation, including lag effects. Spruce share increased from 12% in 1902 to 27% in 2015 and then declined to 9% by 2018. In 2015, 75% of spruce-dominated stands occurred in unsuitable habitats. Bark beetle outbreaks were significantly associated with drought, with outbreak years showing lower precipitation (–121 mm), reduced Selyaninov k (mean 1.40 vs. 1.61), and more negative SPEI-12 values (–0.48 vs. 0.07) compared to non-outbreak years (p < 0.05). One-year lag analysis indicated drought as both a predisposing and triggering factor. These findings highlight the interaction of habitat suitability and drought as a key driver of spruce decline, supporting adaptive management strategies that retain spruce in optimal habitats while converting suboptimal stands to more drought-tolerant species. Full article

Background: Ash dieback, driven by the invasive fungal pathogen Hymenoscyphus fraxineus, has precipitated severe declines in Fraxinus excelsior L. populations across Europe, threatening genetic diversity and ecosystem stability. Methods: This study investigates the interplay between phenotypic vitality and genetic variation in five Polish ash stands using nuclear simple sequence repeat (nSSR) and chloroplast DNA (cpDNA) markers. Vitality assessments of 186 trees across three reserves (from Białowieża Primeval Forest and Wolica Reserve) were conducted. Results: Vitality assessments revealed a slight predominance of dying individuals (36%, 3rd degree of Roloff classification). Nuclear analyses indicated moderate to high diversity (mean H_E = 0.826), significant inbreeding (F_IS = 0.178, p < 0.001), and low inter-population differentiation (F_ST = 0.044) among all five stands. Chloroplast markers showed elevated differentiation ($\mathsf{\Phi }$_ST = 0.228, p < 0.0001), reflecting phylogeographic structure. Vitality degrees assessed in three chosen populations (Browsk FD, Hajnówka FD, and Chojnów FD) exhibited negligible genetic differentiation (nSSR F_ST = 0.009; cpDNA $\mathsf{\Phi }$_ST = 0.003), suggesting gene flow mitigates pathogen-induced selection. Bayesian clustering (STRUCTURE, K = 3) revealed admixture with distinct genotypes in dying trees, potentially linked to susceptibility. Conclusions: These findings underscore the resilience of ash genetic pools and advocate for selective breeding in nurseries to prevent the spread of dieback, prioritizing resistant genotypes for conservation. Full article

Spores offer the most accessible diagnostic characters for the early-divergent Lycopodiaceae. We quantified eight morphometric traits—equivalent diameter, polar length, equatorial width, projected area, perimeter, and aspect ratio—in a balanced sample of 50 spores from each of six Central European taxa (Diphasiastrum alpinum, D. tristachyum, D. complanatum, Lycopodium annotinum, L. clavatum, and Huperzia selago) collected in the Białowieża Primeval Forest. Integrated light-microscope and scanning-electron-microscope imaging revealed three discrete wall-ornamentation syndromes (reticulate, verrucate, and granulose) that parallel the quantitative gradients. Principal component analysis showed that a single, collinear size axis accounts for 79% of variance, situating H. selago at the large-diameter extreme (mean: $37\mathsf{\mu }\mathrm{m}$) and the three Diphasiastrum species at the small-diameter pole (mean: 32–$33\mathsf{\mu }\mathrm{m}$). One-way ANOVA ($p<{10}^{-31}$) and PERMANOVA ($R^2=0.52$) confirmed decisive interspecific separation that mirrors published molecular phylogenies, underscoring a strong phylogenetic signal in spore form. While trait baselines are taxonomically stable, moderate microhabitat-driven shifts indicate limited ecophenotypic plasticity. The resulting high-resolution benchmark refines palynological identification, enables rapid spore-based bioindication of demographic stress, and strengthens conservation monitoring in relic temperate forest ecosystems. Full article

Forests, both natural and managed, provide a critical habitat for a significant part of global biodiversity. Among many different groups of forest biota, tree species occupy a special position as they create conditions upon which the existence of virtually all other forest organisms depends, either directly or indirectly. To permanently play this role, particular tree species must be demographically stable; i.e., their populations should be distinguished by the balanced, size-dependent proportions of individuals representing different developmental stages (from seedlings and saplings to mature and old trees). In this study, we examined the extent to which this condition is met in the managed part of Białowieża Forest in northeastern Poland, an important biodiversity hotspot in Central Europe. Comparison of species-specific equilibrium vs. actual size distributions revealed that almost half of all trees growing in Białowieża Forest represented “inappropriate” (i.e., occurring in excess compared to the balanced models) species and/or diameter ranges. The amount of deficits was also large (around 30% of the current tree number), concerning primarily the smallest trees. Considering this, we recommend targeted, active management strategies to restore the demographic balance of key tree species and, thus, to enhance the conservation of local biodiversity. We also indicate that the key elements of such strategies should be the gradual removal of trees from surplus diameter ranges and assisted regeneration of species with the greatest deficiencies in small diameter classes. Full article

This study conducted a multi-directional evaluation of the chemical potential and biological properties of selected European fungal species of the genus Phellinus. We investigated 30 samples belonging to 22 Phellinus species. Fruiting bodies were collected, among other specimens, in the Białowieża Forest (Poland); Village Kozhle (North Macedonia); Estremadura, Sesimbra, and Lagoa de Albufeira (Portugal); Zlatari close to Prishtina (Kosovo); and Spoleto and the Bosco Siro Negri State Nature Reserve (Italy). Morphological identification of the collected fungi was carried out, and genetic tests were performed to confirm the identity of the collected specimens. Methanol extracts for biological activity tests were prepared. Screening of antimicrobial activity of 30 methanolic extracts was performed on strains of bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Kocuria rhizophila) and fungi (Candida albicans). Antioxidant activity tests (DPPH and ABTS) were also performed. The three most biologically active fungi species were selected (Phellinus igniarius, Fomitiporia robusta, and Porodaedalea pini) for further research. The chemical composition of the extracts was determined using GC-MS analysis. Thermal decomposition studies and spectroscopic analysis of the dry fruiting bodies were performed. The extracts were tested for their antimicrobial activity against antibiotic-resistant bacteria. Cytotoxic activity was also tested. Full article

Our research focused on the roost preferences of two bat species in a forest environment. Throughout the Anthropocene, people have heavily altered the landscape. Forested habitation has declined, with remaining forests becoming fragmented and often deprived of old trees that provide shelter opportunities for bats. TReMs (tree-related microhabitats) are essential for forest-dwelling bat species as they provide an opportunity to roost and shelter. Following an infestation of Ips typographus L., the Białowieża Forest is saturated with dead spruce trees. We investigated roost selection in two forest-dwelling species, Barbastella barbastellus and Pipistrellus pygmaeus. To examine similarities or differences in roost selection between species, we radio-tracked 24 barbastelles and 13 soprano pipistrelles over three breeding seasons. We located a total of 48 barbastelle roosts and 15 pipistrelle roosts, together with the characteristics of the surroundings. We found that barbastelles select roosts almost exclusively in dead spruce trees (43/48), while pipistrelles selected roosts predominantly in live (n = 8) and dead (n = 5) broadleaved trees. Our results show that both bat species have clear differences in roost tree preference. In our study area, with an abundance of exfoliating bark, barbastelles showed a preference for roosting under flaking bark despite the availability of crevices within broadleaved trees. Our findings provide useful insight into forestry practices, highlighting the importance of standing dead trees. Full article

Groundwater is the primary water source for ecosystems, and so changes in groundwater levels, if directional and constant, can cause changes in vegetation and habitat characters. In Białowieża National Park, a significant decline in the water table was observed at the beginning of the 20th century. The question therefore arose as to whether the changes that occurred at that time were permanent. A second question was whether the negative trend would continue so clearly in the following years. The study is based on measurements from 1985 to 2005 and 2022 to 2023 taken in the same monitoring wells. Complete data were collected from 21 monitoring wells. An analysis of groundwater levels between 1985 and 2005 showed an average decline of 0.08 m/10 years in swamp habitats, 0.11 m/10 years in moist habitats, and 0.21 m/10 years in fresh habitats. The measurements in 2022 and 2023 showed that the trend of falling water levels had slowed down in almost the entire study area, with water levels in recent years being similar to those at the beginning of the century. This was also confirmed by comparing years with similar precipitation: 2022 with 1986, and 2002, 2004, and 2023 with 1999. This was due to the higher precipitation after 2005. In the period of 2006–2023, precipitation in the hydrological years was on average 60 mm higher than in the period of 1985–2005. Despite the clear trend toward rising air temperatures, the higher precipitation compensated for the higher evapotranspiration. However, one area showed a systematic decrease in water levels. This occurred at the watershed of the two largest rivers in the Białowieża Forest. The findings indicate that watershed areas are most vulnerable to lowering the groundwater level due to climatic warming. Full article

The Białowieża Forest is home to both primary forests under strict protection and commercial forests, which provides an opportunity to compare them in terms of the number of individuals, number of species, and composition of different animal assemblages. The main goal of our study was to compare spider assemblages inhabiting herbaceous vegetation in these two types of forest stands. Spiders were sampled using a sweep net in an oak–lime–hornbeam forest, an ash–alder forest, and an alder carr. More spiders were found in unmanaged stands compared to managed stands, but a significant difference was found only in the alder carr. Total species richness did not significantly vary between managed and unmanaged stands in all forest types. In the oak–lime–hornbeam forest, more species per sample were found in commercial stands compared to primeval stands, while the result was the opposite for the alder carr. Our research did not show a clear negative impact of forest management on plant-dwelling spiders. The impact of forest management was evident in the case of the riparian forest, where the managed stand was characterized by low canopy cover as a result of logging carried out years ago, which is likely to have resulted in differences in family composition. Full article

Remote sensing technologies like airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) have emerged as efficient tools for detecting and analysing canopy gaps (CGs). Comparing these technologies is essential to determine their functionality and applicability in various environments. Thus, this study aimed to assess CG dynamics in the temperate European Białowieża Forest between 2015 and 2022 by comparing ALS data and image-derived point clouds (IPC) from DAP, to evaluate their respective capabilities in describing and analysing forest CG dynamics. Our results demonstrated that ALS-based point clouds provided more detailed and precise spatial information about both the vertical and horizontal structure of forest CGs compared to IPC. ALS detected 27,754 (54%) new CGs between 2015 and 2022, while IPC identified 23,502 (75%) new CGs. Both the average gap area and the total gap area significantly increased over time in both methods. ALS data not only identified a greater number of CGs, particularly smaller ones (below 500 m²), but also produced a more precise representation of CG shape and structure. In conclusion, precise, multi-temporal remote sensing data on the distribution and size of canopy gaps enable effective monitoring of structural changes and disturbances in forest stands, which in turn supports more efficient forest management, e.g., planning of forest regeneration. Full article

The ash dieback epidemic, caused by the fungus Hymenoscyphus fraxineus, has been a significant issue in Europe for over 20 years, severely affecting ash tree populations (Fraxinus excelsior L.). In the Białowieża Forest, ash trees now represent less than 1% of the species composition, with a sharp decline observed over the past several decades. This study aims to map the dynamics of ash mortality in the Białowieża Forest and assess the influence of habitat and stand factors on the severity of mortality. We utilized bi-temporal high-resolution remote sensing data from 2015 to 2019 to track the decline of ash trees and to identify factors affecting mortality. The analysis employed a combination of Boosted Regression Trees (BRTs) and hotspot analyses. Our results show that between 2015 and 2019, 29% of the living ash trees in the canopy layer of the forest died. The findings indicate that ash mortality was most pronounced in stands with a high proportion of ash trees, particularly where dead deciduous trees were already present. Intensive dieback of other deciduous trees was also noted in these stands. This study provides valuable insights into the factors influencing ash mortality dynamics and demonstrates the potential of remote sensing for large-scale monitoring of tree health. The results have important implications for forest management and conservation, offering baseline data that can inform strategies to manage ash dieback and guide targeted interventions in affected forest areas. Full article

In the Białowieża Forest, Norway spruce is the preferred host tree species for wood ants, both in coniferous and mixed stands; thus, spruce mortality as a consequence of a continuous spruce bark beetle outbreak in the Białowieża Forest since 2012 could have severe consequences for wood ant colonies, as well as their vitality and distribution. The main aim of this study was to assess whether the bark beetle outbreak had any effects on wood ant nest density and abundance and whether we could find any factors affecting the dead spruce distribution around ant nests. A re-inventory of active and abandoned wood ant nests in our study area was conducted from April to July 2022, using the same procedure as the previous inventory performed in 2016. The wood ant nest density was 0.11 per ha and remained practically the same relative to that determined in 2016. Our results indicate that, despite the importance of spruce for wood ants, in situations when only part of the spruce trees die, natural forest disturbances such as bark beetle outbreaks can actually have positive effects because more light can reach the forest floor, thereby promoting the establishment of new nests. Full article

Polyporoid fungi represent an untapped resource in the ancillary use of forests, traditionally utilized in both historic and contemporary medicine for their diverse bioactive properties, yet their potential for creating materials within the food industry remains largely unexplored. This article delves into the polyporoid fungi as a promising, yet underutilized, biomaterial resource for eco-friendly applications in the food sector. Despite their widespread use in traditional and modern medicine, the exploration of these fungi for industrial applications, particularly in food storage solutions and utensils, is in its nascent stages. The Białowieża Primeval Forest, characterized by its abundant deadwood and minimal human intervention, offers a rich repository of polyporoid fungi. This study aims to illuminate the ecological significance and potential industrial applications of polyporoid fungi. By reviewing existing research and synthesizing insights into the genetic diversity, biochemical capabilities, and ecological roles of polyporoid species such as Fomes fomentarius, Fomitopsis pinicola, and Trametes versicolor, this article proposes a novel approach to leveraging polyporoid fungi in developing sustainable solutions that meet current environmental and health-conscious trends. The investigation not only underscores the potential of polyporoid fungi in advancing green technologies but also highlights the importance of utilizing renewable resources in material science, fostering a shift towards more sustainable industrial practices. Full article

Deadwood plays an important role in forest ecology; its degradation and, therefore, carbon assimilation is carried out by fungi and bacteria. To quantify the abundance and distribution of microbial taxa inhabiting dead spruce logs fallen over a span of 50 years and the soil beneath, we used taxonomic profiling with NGS sequencing of hypervariable DNA fragments of ITS1 and 16S V3-V4, respectively. The analysis of sequencing data revealed a high level of diversity in microbial communities participating in the degradation of spruce logs. Differences in the relative abundance of microbial taxa between the samples of the wood that died in 1974 and 2014, and of the soil in its immediate vicinity, were visible, especially at the genus level. Based on the Lefse analysis significantly higher numbers of classified bacterial taxa were observed in the wood and soil samples from 2014 (wood: 1974-18 and 2014-28 taxa; soil: 1974-8 and 2014-41 taxa) while the number of classified fungal taxa was significantly higher in the wood and soil samples from 1974 (wood: 1974-17 and 2014-9 taxa; soil: 1974-57 and 2014-28 taxa). Most of the bacterial and fungal amplicon sequence variants (ASVs) unique to wood were found in the samples from 1974, while those unique to soil were detected in the samples from 2014. The ATR-FTIR method supported by CHN analysis revealed physicochemical changes in deadwood induced by the activity of fungal and bacterial organisms. Full article