Biomass of external mycelium of ectomycorrhizal fungi in Norway spruce stands in Poland

Biomass of extramatrical mycorrhizal mycelium (EMM) was examined under canopies of mature Norway spruce trees grown in different forest stands in Poland. Two mountain forest sites (Brenna and Salmopol), one upland site (Zwierzyniec) and one lowland site (Mirachowo) have been investigated, using sand-filled mesh-bags method. The in-grow mesh-bags were buried in the soil for 12 months (since October up to the next October) or for 4 months (since June up to October) at four depths at each site: 5, 15, 30 and 45 cm (Brenna and Salmopol) or 60 cm (Zwierzyniec and Mirachowo). The mycelium biomass was estimated from the ergosterol content determined in the mesh-bags. The results indicated significant differences in EMM production and their vertical distribution between the mountain and the upland and lowland forest sites. The lowest EMM biomass was found at the experimental plot in the mountainious site Brenna. Considerable decrease of EMM biomass with the soil depth was recorded after 12 months of the mesh-bags incubation in soil in the upland and lowland sites, while in the mountain forests decrease of the EMM biomass in the lower soil depths diminished more gradually EMM biomass determined in the mesh-bags placed in soil at the upper 5 and 15 cm tended to be higher after 4 months than after 12 months of incubation period. Such results suggest that the time necessary for evaluation of EMM biomass in soil may be limited to the summer–autumn months, when the production of EMM is the highest. Variable stress factors can influence decreased ectomycorrhizal mycelium production and/or their destruction. Further research in different forest types and regions are needed for better understanding factors determining EMM biomass production and surviving in soil

A Numerical Analysis of the Working Machine Tyre Inflation Process to Ensure Operator Safety

Tyre replacement and inflation is a common occurrence in the transportation, construction and mining industries, but in commercial, off-highway, or earth-moving vehicles, the rupture of an inflated tyre can cause serious or even fatal injuries to an operator. This paper highlights the consequences of a burst tyre based on a real case. The presented analytical approach is based upon an assumed adiabatic process and continuum mechanics using Bernoulli’s flow equations. A numerical analysis of a tyre burst was performed using multibody and finite element methods to reconstruct the fatal accident. It was shown that tyre-blast injuries may lead to lethal head trauma and bodily injuries, since the potential energy stored in large, over-pressured tyres can exceed 1 MJ

Soil Microbial Biomass and Community Composition Relates to Poplar Genotypes and Environmental Conditions

Poplars, known for their diversity, are trees that can develop symbiotic relationships with several groups of microorganisms. The genetic diversity of poplars and different abiotic factors influence the properties of the soil and may shape microbial communities. Our study aimed to analyse the impact of poplar genotype on the biomass and community composition of the microbiome of four poplar genotypes grown under different soil conditions and soil depths. Of the three study sites, established in the mid-1990s, one was near a copper smelter, whereas the two others were situated in unpolluted regions, but were differentiated according to the physicochemical traits of the soil. The whole-cell fatty acid analysis was used to determine the biomass and proportions of gram-positive, gram-negative and actinobacteria, arbuscular fungi (AMF), other soil fungi, and protozoa in the whole microbial community in the soil. The results showed that the biomass of microorganisms and their contributions to the community of organisms in the soil close to poplar roots were determined by both factors: the tree-host genotype and the soil environment. However, each group of microorganisms was influenced by these factors to a different degree. In general, the site effect played the main role in shaping the microbial biomass (excluding actinobacteria), whereas tree genotype determined the proportions of the fungal and bacterial groups in the microbial communities and the proportion of AMF in the fungal community. Bacterial biomass was influenced more by site factors, whereas fungal biomass more by tree genotype. With increasing soil depth, a decrease in the biomass of all microorganisms was observed; however, the proportions of the different microorganisms within the soil profile were the result of interactions between the host genotype and soil conditions. Despite the predominant impact of soil conditions, our results showed the important role of poplar genotype in shaping microorganism communities in the soil

Effective Molecular Identification of Ectomycorrhizal Fungi: Revisiting DNA Isolation Methods

A better understanding of ectomycorrhizal symbiosis leads to numerous advancements in forest management and environmental protection. The morphological identification of the ectomycorrhizae often proves to be misleading. For this reason, in order to study the ectomycorrhizal fungi communities, a number of molecular methods that require the isolation of nucleic acids are being used. However, ectomycorrhizal root tips, low mass heterogenic material rich in inhibitors, are a recalcitrant substrate in DNA isolation. It is common for published studies to include some number of unidentified root tips in their results, in spite of diverse isolation protocols being available to researchers. This study aims to analyze the relationship between the collected fungal material and later isolation results, and to propose a DNA isolation protocol specifically optimized for ectomycorrhizal root tips. It was found that the taxonomic position can be used to predict the potential isolation efficiency, with Ascomycota being generally more difficult from which to isolate DNA. After a number of cell lysis and lysate purification methods were evaluated, the joined approach of mechanical and chemical lysis, followed by silica column purification, was found to provide the best results, even with recalcitrant material

Insect herbivory response to Populus nigra genetic diversity

Recent research suggests that genetic diversity in tree population may shape associated species assemblages and then drive ecosystem processes. Trees can support large numbers of insect species and some functional traits of trees have been shown to have major influence on insect communities and resultant damage. Studying the response of insect herbivore populations to the genetic diversity of tree populations is therefore a relevant approach to test community genetics hypotheses. The objective of our study was to evaluate how insect herbivory is affected by genotypes of Populus nigra, a dominant native poplar species in riparian forests of Europe. In a field experiment, we planted eight native P. nigra clones in plots of increasing genetic diversity with combinations of one to six clones. Insect herbivory was measured using visual estimation of leaf damage by six functional guilds of insects: chewers, skeletonisers, leaf miners, gall makers, leaf rollers, sap suckers and sap feeders. Response of insect herbivory to increasing genotypic diversity was analysed by considering the net diversity effect which was further divided in a complementary and a selection effects. Overall we observed slightly higher insect herbivory in poplar clone mixtures than in clone monocultures. This pattern was due to two opposite mechanisms. There was a positive complementary effect, with higher associational susceptibility in more genetically diverse mixtures. On the other hand, the selection effect also increased with the genetic diversity as the more diverse clone mixtures were more likely to comprise insect resistant clones

Insect herbivory response to Populus nigra genetic diversity

Recent research suggests that genetic diversity in tree population may shape associated species assemblages and then drive ecosystem processes. Trees can support large numbers of insect species and some functional traits of trees have been shown to have major influence on insect communities and resultant damage. Studying the response of insect herbivore populations to the genetic diversity of tree populations is therefore a relevant approach to test community genetics hypotheses. The objective of our study was to evaluate how insect herbivory is affected by genotypes of Populus nigra, a dominant native poplar species in riparian forests of Europe. In a field experiment, we planted eight native P. nigra clones in plots of increasing genetic diversity with combinations of one to six clones. Insect herbivory was measured using visual estimation of leaf damage by six functional guilds of insects: chewers, skeletonisers, leaf miners, gall makers, leaf rollers, sap suckers and sap feeders. Response of insect herbivory to increasing genotypic diversity was analysed by considering the net diversity effect which was further divided in a complementary and a selection effects. Overall we observed slightly higher insect herbivory in poplar clone mixtures than in clone monocultures. This pattern was due to two opposite mechanisms. There was a positive complementary effect, with higher associational susceptibility in more genetically diverse mixtures. On the other hand, the selection effect also increased with the genetic diversity as the more diverse clone mixtures were more likely to comprise insect resistant clones

Preliminary studies of fungi in the Biebrza National Park. Part IV. Macromycetes – new data and the synthesis

The paper presents the last part of the results of the short-term inventory of fungi species in the Biebrza National Park and synthesises all the data gathered during two surveys, including the information published by other authors. The main body of research is focused on a survey of macrofungi identified with morphology-based methods. In case of some specimens molecular technics have been applied. In total 346 macrofungal taxa (21 belonging to ascomycetes and 325 to basidiomycetes) were found during the survey, including 186 species unobserved during the previous inventory in 2012. As a result of previous and ongoing studies, the current number of macrofungi recorded from the Biebrza National Park reached 508 species. Among them eight taxa are newly reported for Poland (Conocybe velutipes var. nitrophila, Entoloma caeruleum, E. plebejoides, Inocybe rennyi, I. vulpinella, Pholiota pityrodes, Pholiotina utricystidiata, and Tomentella pilosa). The next seven species (Bovista paludosa, Fistulina hepatica, Ganoderma lucidum, Geastrum schmidelii, Inonotus obliquus, Tulostoma kotlabae, and Xerocomus parasiticus) are protected by law and 95 species belong to red-listed species. The results of two intensive, but relatively short-term survey clearly indicate the Biebrza National Park as a hot spot of macrofungi and suggest the need to undertake extended and regular inventories also in other Polish national parks