Anna Tereba

Urban-driven landscape fragmentation is a major factor contributing to amphibian population decline yet its genetic consequences remain incompletely understood. We examined the genetic structure and variability of the common toad (Bufo bufo) in Warsaw, Poland, using seven nuclear microsatellite loci and mitochondrial cytochrome b sequences (800 bp). Samples (N = 97) were collected from six breeding sites representing contrasting urban habitats on both banks of the Vistula River. Genetic analyses revealed low but significant population differentiation, elevated inbreeding coefficients, and a heterozygosity deficit despite relatively high effective population sizes. This pattern is consistent with post-fragmentation genetic inertia, in which demographic buffering temporarily maintains genetic diversity despite reduced connectivity. Consequently, contemporary genetic patterns may underestimate the extent of ecological isolation imposed by urban infrastructure. Mitochondrial analyses identified seven haplotypes, including six previously unreported, forming a star-like network topology indicative of a single postglacial colonization event. The Vistula River did not constitute a significant barrier to gene flow, based on pairwise F_ST and hierarchical AMOVA. Supervised feature selection (MCFS-ID) identified specific alleles and body mass as key discriminants among sites, suggesting emerging responses to local urban conditions. Our results indicate that urban common toad populations can retain substantial genetic variation despite fragmentation, although continued isolation may ultimately increase inbreeding and genetic drift.

Ponds created by beavers represent unique aquatic ecosystems that influence hydrological, chemical and biological conditions, including the microbiology of the water. The activity of these animals promotes biodiversity and water purification processes, but can also lead to the accumulation of pollutants. Water retention in beaver ponds promotes the development of bacteria and other microorganisms that play an important role in biogeochemical cycles. Long‐term water stagnation can lead to anaerobic conditions and the formation of toxic compounds, which in turn can limit the diversity of benthic organisms. Beavers play a key role in shaping these habitats, and microbiological studies of their reservoirs provide a better understanding of their impact on aquatic ecosystems, self‐purification processes and potential biological threats. Metagenomic analysis revealed the presence of 365 bacterial species in water and sediment samples, belonging to 174 genera and 83 families. 83 operational taxonomic units (OTUs) were identified, 62 of which were present in both water and sediments. Although the overall OTU composition was similar in both environments, greater variability was observed in the sediments. The statistical differences in OTU distribution between water and sediments were confirmed using the Wilcoxon test.

Cockchafers Melolontha spp. are polyphagous root pests and outbreak species of considerable economic importance to forestry in Europe. Knowledge of genetic diversity within and between cockchafer populations is largely unexplored but could lead to more effective monitoring and management strategies of these pests. In this study, we fill several gaps in the knowledge of the genetic population structure of Melolontha melolontha and Melolontha hippocastani. Using microsatellite loci and over 200 individuals per species, we examined the genetic structure of Melolontha spp. populations collected from three primary outbreak areas in central and southeastern Poland. We demonstrated that our focal species share some common genetic patterns, such as considerable genetic diversity within subpopulations (within sampling sites) with minor effects of past bottlenecks possibly masked by current population sizes. The estimates of effective population sizes, although subject to wide credibility intervals, indicated a large number of individuals contributing to further generations of the population. The migration rates exceed the threshold of one per generation required for gene flow and maintenance of population equilibrium, indicating limited impact from forest management practices on either cockchafer species. While genetic differentiation was observed in M. melolontha populations, supported by various indices (fixation index, principal coordinate analysis, assignment tests), the M. hippocastani populations were genetically similar. This disparity may hint at the potential historical divergence between these species. In this aspect, more detailed phylogeographic and population genetic studies covering a large area of the Palaearctic distributions of both species are required. Our findings constitute one of the initial efforts aimed at delineating the genetic diversity, differentiation, population structure, gene flow, and migration patterns within Melolontha spp. This exploration is especially significant for M. hippocastani, given its completely unexplored genetic population structure.

Biodiversity within composting systems involves a variety of microorganisms including nematodes. In the research, nematode populations were monitored within six simultaneously operating composting processes. These processes involved varying proportions of feedstock materials. The primary objective was to evaluate the consistency of nematode community succession patterns across the composting processes over a time of 3 months. During the study, samples were taken every month to isolate nematodes, determine the population density of the five trophic groups (per genus) and determine the dominant nematode species. It was shown that the bacterial-feeding community maintained dominance, while the fungus-feeding nematodes gradually increased in dominance as the maturation process progressed. The presence of predatory nematodes Mononchoides which were initially absent, along with the total absence of parasitic nematodes in the late stages of waste stabilization, serves as strong evidence for the reliable evaluation of the biodegradable waste processing level. Based on the obtained results, it is evident that the succession of nematode communities holds promise as a reliable method for evaluating compost maturity.

Tuber wenchuanenseascomata (Ascomycota, Pezizales), a species originally described from Sichuan (China), were found in the Tatra Mountains in southern Poland. The purpose of this work was to (i) report and assess the first case of the holarctic natural distribution of aTuberspecies, (ii) amend the original description of the species, (iii) summarize data on its host plants and (iv) describe its ectomycorrhiza. Specimens ofTuber wenchuanensefrom the Tatra Mountains were studied morphologically and molecularly. The ectomycorrhiza of this truffle withPicea abieswas described for the first time. The distribution ofT. wenchuanense, which is reconstructed based on sequences deposited in the publicly available nucleotide sequence databases, makes it the first holarcticTuberspecies and the one with the northernmost habitat. In fact, its habitat is confined mainly to mountain coniferous forests and alpine and arctic tundra; although, according to known observations, the fruiting bodies ofT. wenchuanensecan be produced only under conifers. Based on the sequences of the internal transcribed spacer, this species appears to have low genetic variability over the entire distribution range. The phylogenetic tree showed that some of the unidentified phylotypes from the Rufum clade found by other researchers belong toT. wenchuanense. The ecological implications of these findings are discussed.

In 2017, the presence of the fly Suillia gigantea (Meigen, 1830) was noted in Poland, after many years of research related to the ecology of insects associated with the fruiting bodies of hypogeous fungi. Finally, in 2020, after further studies, the distribution of the truffle fly in Poland was confirmed. Six adults were reared from larvae inhabiting the fruiting bodies of Burgundy truffle (Tuber aestivum Vittad. (1831)). The fungi were harvested in southern Poland. Morphological and genetic analyses of the insect specimens were performed. For the first time, the DNA sequence of this fly species was isolated. This is the first record of S. gigantea in Poland, although it has already been reported from neighbouring countries. The development of S. gigantea, also known as the truffle fly, is associated with hypogeous fungi, mainly belonging to the genus Tuber P. Micheli ex F.H. Wigg. (1780). The diptera larvae develop inside the fruiting bodies. This type of damage causes great losses in truffle production. Containment of these losses is of great interest to the truffle industry. Knowledge of truffle-inhabiting insects is crucial for the development of effective methods to protect truffle crops in Europe.

In the old pine stands of national parks, it is possible to observe genetic processes in a state free from disturbance by humans. Studies of this type make it possible to evaluate the effectiveness of the conservation of genetic variation and its transfer between generations. The present study was conducted in the largest national forest park in Poland, located in the Central European pine area. The oldest stands of Kampinos National Park and their natural descendants were selected for detailed analyses. The main objective of the study was to compare the mother pine stand, excluded from forest management, with its progeny generations on the basis of their chloroplast DNA (cpDNA), which was used as a diagnostic tool. The results demonstrate significant genetic difference between the maternal and progeny generations of the studied sites. The degree of variation observed in the maternal generation haplotypes in the present study was found to be reduced in the next generation. A significant proportion of the genetic diversity of the studied stands was also lost in the subsequent progeny generation. The obtained results allow conclusions to be drawn about the genetic processes taking place in valuable old-growth forests.

Scots pine (Pinus sylvestris L.) is a widespread species in Eurasia, but its natural range can be significantly altered by a variety of stressors. The ability of pine to regenerate naturally is significantly reduced by its occurrence in unsuitable habitats. The processes of natural selection of pine from select habitats can be followed in stands of national parks where forestry activities are excluded. The possibility of pine regeneration is influenced by the following factors: characteristics of produced seeds, competition, and genetic characteristics. In the present study, selected factors associated with limiting the natural regeneration potential of pine were analysed. The present work generated important information related to the natural regeneration potential of pine in Central and Eastern Europe. The main objective of the analyses was to discuss the possibility of the natural regeneration of pine stands without human intervention. In addition, the genetic diversity of naturally germinating seedlings was analysed. The obtained results confirmed the high reproductive potential of pine despite the advanced age of the studied trees. The obtained seeds produced by old growth Scots pine trees had high viability, while a significant difference was observed in terms of the average number of cones per dominant tree between studied stands. Thus, the number of cones was the main element determining the regeneration potential of the stands. It should be emphasised that the number of cones did not influence the occurrence of natural regeneration. Based on the obtained results, the regeneration potential of pine stands depends mainly on the habitat and the competitive pressure. In addition, a correlation between genetic parameters and the regeneration potential of stands should be established, which may be the beginning of further research on the process discussed in this publication.

Biodiversity at the species and individual levels is one of the fundamental elements characterizing an ecosystem. It is assumed that the greater the level of biodiversity, the more tolerant the environment is to changes in external conditions. In recent years, dynamic climate change has negatively impacted the health of many forest trees across Europe, in particular Scots pine. Tree health is commonly characterized by crown defoliation. The study presented here describes and correlates crown defoliation with biodiversity indicators at the species and individual tree levels. Research was conducted in two national parks in Poland (Kampinoski and Bory Tucholskie). Since stands have been under legal protection for many years and forest management is not practiced there, stand development processes taking place there are similar to natural ones. This study provided empirical data on ecosystem response to external stresses based on species and genetic structure. The results confirm differing health of the populations, which results from, among other factors, stand age and the environmental conditions in which they grow. Pine stands in both national parks are genetically diverse but with low genetic variability. Differences in stand health are related to the number of alleles forming the genetic pool. This conclusion is supported by a high correlation coefficient for interactions between defoliation, the number of alleles, and the Shannon index for genotypes. This suggests that greater gene diversity is likely to provide a wider range of phenotypic responses to environmental change.