Decomposing benefits: Examining the impact of beech deadwood on soil properties and microbial diversity.

Deadwood is an important element of forest ecosystems that affects many of its components, including the soil environment. Our research is an attempt to determine the role of decaying wood in shaping the properties of forest soils in mountain ecosystems. The aim of our research was to present the influence of beech deadwood on physicochemical properties and microbiological diversity of soils. The research was carried out in the Baba Góra Massif at its northern exposure. The research plots were established in the altitude gradient at 600, 800 and 1000 m above sea level. On each plot, samples were taken from decaying wood, from the soil directly under the decaying log, and a soil sample 1 m from the log as a control. We determined the basic properties of the samples, that is pH, C and N concentration and lignin content. The enzymatic activity and additionally, the taxonomic composition of soil bacterial and fungal communities was determined in the collected samples. Our research indicates the important role of decaying beech wood in shaping the properties of forest soils. We noted a positive effect of decaying wood on the properties of the tested soils. Soils affected by deadwood were characterized by significantly higher pH, C and N concentrations compared to control soils, regardless of their location in the altitude gradient. Additionally, we found that soils affected by decaying wood are characterized by a different composition of microorganisms regardless of their location in the altitude gradient. In control soil the fungal and bacterial alpha diversity were lowest compared with the deadwood and soil under the influence of deadwood. Our results may have practical applications in the management of forest ecosystems. The presented results indicate the possibility of leaving deadwood in order to improve its basic physicochemical properties and increase microbial diversity.

The impact of root systems and their exudates in different tree species on soil properties and microorganisms in a temperate forest ecosystem.

BACKGROUND: The species composition of tree stands plays an important role in shaping the properties of forest soils. The aim of our research was to determine the influence on soil properties of the root systems of six species of trees which form forest stands in the temperate climatic zone. The research covered areas including six tree species - Scots pine (Pinus sylvestris L.), European larch (Larix deciduas Mill.), English oak (Quercus robur L.), English ash (Fraxinus excelsior L.), European beech (Fagus sylvatica L.) and European hornbeam (Carpinus betulus L.). In our study, we determined the characteristics of the roots and the amount of carbon excreted alongside their exudates. Enzymatic activity, and the composition and diversity of the fungi and bacteria, were also determined in addition to the basic physicochemical properties of the soil samples. RESULTS: A strong relationship between the root characteristics and soil properties, including the pH, basic cation content and phosphorus content, was confirmed. In addition, the enzymatic activity of phosphatase, ß-glucosidase, N-acetyl-ß-D-glucosaminidase and ß-D-cellobiosidase were positively correlated with the root characteristics. The study on soil bacteria across different tree species revealed Proteobacteria and Actinobacteriota to be the most abundant phylum. Fungal analysis showed Basidiomycota and Ascomycota as the dominant phyla. Ascomycota dominated in hornbeam and oak soils. Mortierellomycota was remarkably more present in pine soil. CONCLUSIONS: This analysis of root systems and soil properties confirmed the distinctness of ash stands, which were also more abundant in various microorganisms. It was also found that soils affected by different tree species were characterised by varied fungal and bacterial composition. The ash had particularly beneficial impact on soil microbiota.

The role of chemical properties of the material deposited in nests of white stork in shaping enzymatic activity and fungal diversity.

Organic debris accumulated in bird nests creates a unique environment for organisms, including microbes. Built from various plant materials that are typically enriched by animal residues, bird nest favours the development of various fungal groups. The aim of this study was to investigate the chemical properties of the material deposited in the white stork Ciconia ciconia nests and the link between extracellular enzyme activity and the diversity and composition of culturable fungi. Our findings revealed low C/P and N/P ratio values in the nest materials, which indicate a high P availability. Nest material C/N/P ratio ranged from 67/8/1 to 438/33/1. Enzymatic activity strongly correlated with the content of carbon, nitrogen, and pH of the material deposited in the nests. A total of 2726 fungal isolates were obtained from the nests, from which 82 taxa were identified based on morphology and DNA sequence data. The study indicates that white stork nests are microhabitat characterised by diverse chemical and biochemical properties. We found relationship between the fungal richness and diversity and the C/P and N/P ratios of materials from the nests. Our study showed that culturable fungi occurred frequently in materials with high levels of C, N, and P, as well as high concentrations of base alkaline elements (Ca, Mg, and K).

The effect of shrubs admixture in pine forest stands on soil bacterial and fungal communities and accumulation of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent toxic pollutants. The species composition of the stand is important in shaping the quality of soil organic matter and, consequently, the PAH content. The main purpose of the research was to determine the role of shrubs in shaping PAH accumulation in forest soils. The study covered the soils of the pine stands of the Rybnik Forest District, which experiences some of the highest deposition of industrial emissions in Europe. Pine stands with admixture of shrubs (alder buckthorn Frangula alnus and European hazelnut Coryllus avellana) growing in the same soil conditions were selected for the study. Samples for analyses were collected from the organic horizon (O) (from a depth of 0-7 cm) and humus mineral horizon (A) (from a depth of 7-15 cm). The organic C and total N concentrations, pH, alkaline cation content, soil enzyme activity and PAH content were determined. Additionally, the taxonomic composition of soil bacterial and fungal communities was determined. The highest activity of enzymes was noted in soils under influence of shrubs. The enzymatic activity was positively correlated with the content of total N, organic C, pH H2O and KCl and negatively with the C/N ratio. The highest PAH content was recorded in the soils of pine stands without the admixture of shrubs. Our research indicates the importance of shrubs in shaping the properties of surface horizons of forest soil and, consequently on the accumulation of PAHs. Shrubs stimulate biochemical activity of soils which results in lower PAHs accumulation by providing more easily decomposable organic matter.

The nutritional status and root development of silver fir (Abies alba Mill.) seedlings growing on decaying deadwood in temperate forest ecosystem.

The study aimed to compare two substrates, soil and deadwood, for the regeneration of silver fir (Abies alba Mill.) seedlings. Three-year-old fir seedlings growing both on deadwood and in the soil were collected. The examination involved determining the physical, chemical, and biochemical properties of soil and deadwood, as well as assessing the morphology of the roots and the nutrition of seedlings growing on the soil and deadwood. The examined substrates differed in physical, chemical and biochemical properties. It was shown that strongly decomposed fir logs are a good substrate for the growth of fir seedlings, mainly due to the high content of exchangeable cations (especially calcium, magnesium and potassium) and high phosphorus and nitrogen content. The type of substrate had a significant impact on the root morphology of fir seedlings. In our study, the most responsive root traits to differences in growing substrates were specific root area (SRA) and specific root length (SRL). Our analyses did not confirm significant differences in the stoichiometry of C, N and P in the roots and needles of seedlings grown on different substrates. The stoichiometry of roots and needles suggests no limitations in the uptake of nutrients by seedlings growing on deadwood. This study validated that heavily decomposed wood can provide favourable microhabitats for the growth of the young generation of fir.

Patterns and driving factors of ecological stoichiometry in system of deadwood and soil in mountains forest ecosystem.

The aim of our research was to identify the factors that most strongly determine the C, N and P cycles in the deadwood-soil system in mountains forest ecosystems. We assumed that the climatic conditions resulting from the location in the altitude gradient and rate of deadwood decomposition most strongly determine the C/N/P stoichiometry. A climosequence approach comprising north (N) and south (S) exposure along the altitudinal gradient (600, 800, 1000 and 1200 m a.s.l.) was set up. Spruce logs at different decomposition stages (III, IV and V) were selected for the analysis in Babiogórski National Park (southern Poland). We calculated the C/N/P stoichiometry for deadwood and soil samples to reflect the nutrient availability. Our research indicates a very strong influence of the location conditions in the altitude gradient on the C/N/P stoichiometry. The GLM analysis confirmed the importance of high elevation in shaping the C, N and P content. A strong correlation was confirmed between P content, N content and C/N ratio. A higher C/N/P ratio was found in deadwood compared to soil, regardless of location. Decaying wood is an important source of N and P and the degree of decomposition made a significant contribution to explaining the variability of C, N and P content. The obtained results indicate the need to leave deadwood in forest ecosystems in order to improve biogeochemical cycles. Deadwood, by having a beneficial effect on many components of the forest ecosystem, will improve its biodiversity and, consequently, its stability.

How decaying wood affects the accumulation of polycyclic aromatic hydrocarbons in soil of temperate mountain forest.

The aim of our research was to determine the role of heavily decomposed deadwood in the shaping of accumulation of polycyclic aromatic hydrocarbons (PAHs) in mountain forest ecosystems. The study included heavily decomposed spruce wood located in lower and higher mountain locations (600 and 1200 m a.s.l.) and at the south (S) and north (N) exposure. The accumulation of PAHs in deadwood was compared to the accumulation of PAHs in surface soil horizons in the immediate vicinity of decaying wood and in soils unaffected by decaying wood. Basic chemical properties and enzymatic activity were determined in wood and soil samples. The conducted research indicates the importance of decaying wood for the formation of PAHs accumulation in mountain forest soils. The lowest content of PAHs was recorded in samples of heavily decomposed wood, which at the same time was characterized by the highest enzymatic activity. Significantly higher PAHs content was recorded in soils unaffected by components released from decaying wood. Our research confirmed the importance of location conditions (exposure, altitude) in shaping PAHs accumulation. The highest mountain locations (1200 m a.s.l.) to N exposure were characterized by the highest accumulation of PAHs.

Magneto-chemical characterisation of Saharan dust deposited on snow in Poland.

Recent research has convincingly shown the advantages of combining environmental magnetism and geochemical analyses for the proxy estimation of anthropogenic pollution due to their atmospheric deposition in local environments. Few studies have also focused on anthropogenic particles deposited on snow. However, papers reporting on Sahara dust particles deposited on snow in central Europe and which involve magnetic methods are missing. To the best of our knowledge, this is the first study investigating the magnetic features of the SDE recorded in snowfall in this part of Europe (i.e. Poland). Our aim was to provide the magnetic characteristics and chemical elemental compositions of a snow horizon containing Saharan dust deposited near the Polish Jakuszyce meteorological station during a snowfall event that occurred from the 1st to the February 7, 2021. Samples of snow with and without Saharan dust were analysed with respect to iron oxide contents (magnetic susceptibility, hysteresis loop, magnetic remanence acquisition) and compared with chemical compositions. Our results revealed the presence of both ferrimagnetic magnetite and antiferromagnetic hematite in the dust-enriched horizon, and the diamagnetic behaviour of the reference layer consisting of 'pure' snow. The samples recorded the presence of geogenic elements such as Al, Fe, Mn, and Ti, anthropogenic elements such as As, Co, Cr, Cu, Ni, Pb, and Zn, and nutrients including Ca and K. The total concentrations of geogenic elements, nutrients, and anthropogenic elements in the snow samples with deposited Saharan dust were, respectively, >3700, >320, and >110 times greater than in the samples without Saharan dust. These findings may serve as reference data for a variety of environmental magnetic studies.

Effect of drought on root exudates from Quercus petraea and enzymatic activity of soil.

Root exudation is a key process that determines rhizosphere functions and plant-soil relationships. The present study was conducted with the objectives to (1) determine the root morphology of sessile oak seedlings in relation to drought, (2) assess root exudation and its response to drought, and (3) detect possible changes in the activity of soil enzymes in response to drought enhancement. In the experiment, sessile oak seedlings (Quercus petraea Matt.) were used, and two variants of substrate moisture (25% humidity-dry variant and 55% humidity-fresh variant) on which oaks grew were considered. Exudates were collected using a culture-based cuvette system. Results confirmed the importance of drought in shaping the morphology of roots and root carbon exudation of sessile oak. The oak roots in the dry variant responded with a higher increment in length. In the case of roots growing in higher humidity, a higher specific root area and specific root length were determined. Experimental evidence has demonstrated decreased root exudation under dry conditions, which can lead to a change in enzyme activity. In the study, enzyme activity decreased by 90% for ß-D-cellobiosidase (CB), 50% for ß-glucosidase (BG) and N-acetyl-ß-D-glucosaminidase (NAG), 20% for ß-xylosidase (XYL) decreased by, and the activity of arylsulphatase (SP) and phosphatase (PH) decreased by 10%.

Soil texture as a key driver of polycyclic aromatic hydrocarbons (PAHs) distribution in forest topsoils.

Due to the dynamic development of civilization and the increasing demand for energy, pollution by harmful chemicals, including polycyclic aromatic hydrocarbons (PAHs) compounds, is a serious threat to forest soils. The aim of the study was to determine the role of texture in the distribution of polycyclic aromatic hydrocarbons (PAHs) and trace elements in forest soils. The areas with different texture ranging from sand through sandy loam to silt loam were selected for the study. The study was carried out in the Chrzanów Forest District in southern Poland (50° 7' 18 N; 19° 31' 29 E), which in one of the most intensive industrial emission zones in Europe. The soil samples for properties determination were collected from locations distributed on a regular grid 100 × 100 m (20 points). The samples were collected from the humus horizon (0-10 cm) after removing organic horizon. Basic chemical properties, heavy metal content, polycyclic aromatic hydrocarbons (PAHs) content and magnetic susceptibility values were determined in soil samples. Additionally, enzymatic activity and microbiological biomass was determined in the samples. Our study confirmed the importance of texture in PAHs distribution. A strong correlation between PAHs content and silt content in the soils studied was noted. The regression tree analysis confirmed the importance of the silt content, followed by soil organic carbon in PAHs distribution. Organic carbon content and nitrogen content played a predominant role in controlling the microbial activity. In our study, we did not note a relationship between enzymatic activity, microbiological soil biomass and the amount of PAHs. This may be due to the effective sorption and immobilization of PAHs by particles of fine fractions, especially silt. Obtained results confirmed the usefulness of magnetic susceptibility in the assessment of heavy metals contamination of forest soils. We noted high correlation between magnetic susceptibility value and heavy metals content. Moreover, the relationship between magnetic susceptibility and soil texture of the topsoil was also observed.

Biological and physicochemical properties of the nests of White Stork Ciconia ciconia reveal soil entirely formed, modified and maintained by birds.

The physiological and behavioural activities of animals have far-reaching impacts on the characteristics and functioning of soil. This includes vertebrates, which are capable of modifying the physicochemical and biochemical properties of soil. To date, however, no species is known to be responsible for the entire process of soil formation, modification and maintenance. Large-bodied birds build nests which they then use for several years or even decades. During nest construction or renovation, birds gather and transport to the nesting site organic and mineral matter that includes tree branches of various sizes, twigs, turf, straw and hay. Over time, during subsequent breeding events, adult birds supply further loads of organic matter to the nest, such as food remains, excrement, pellets, feathers, egg shells and other materials. Taking the White Stork Ciconia ciconia as an example, we have shown that the materials deposited in the nests of large-bodied birds gradually produce ornithogenic soils over the years, with distinguishable layers having different physicochemical characteristics and biochemical activities. The tested nesting substrate met the criteria for ornithogenic material; the layers had appropriate thickness and phosphorus pentoxide (P2O5) content. Results of the study indicates that the material contained in White Stork nests have the characteristics of Histosols. Moreover, such nests harbour assemblages of fungi and arthropods that contain species typical of soil mycobiota and fauna, respectively. This study is the first to describe a soil that is formed, modified and maintained entirely by vertebrates and is physically isolated from the ground. Our results highlight the fact that the nests of large birds are unique structures in ecosystems and provide a habitat for a rich and diverse assemblage of organisms.

Soil fungal diversity and biological activity as indicators of fertilization strategies in a forest ecosystem after spruce disintegration in the Karpaty Mountains.

Forest soils are being exposed to nutrient deficiency and acidification at increasing rates as a result of intensive management. Mineral fertilization, however, provides a way to improve soil nutrient balance. The aim of this study is to present the effects of mineral fertilization on the properties of forest soil 11 years after fertilization. Our research investigated the effects of dolomite, magnesite and serpentinite fertilization on the physicochemical properties of the soil, soil biological activity, and fungal diversity. We also determined the condition of a new generation of fir trees after mineral fertilization. In autumn, 2008, fertilizers (dolomite, magnesite and serpentinite, specifically) in the amount of 4000 kg.ha-1 were added to plots in the Wisla Forest District in Poland; one area was left unfertilized to act as the control area for this research. Our results reveal that all fertilization improved the selected soil's physicochemical properties (pH, Ca and Mg content) and accordingly, its biochemical activity; in particular, we found that dolomite (4000 kg.ha-1) contributed heavily to soil improvement. The findings also showed that soil pH and calcium content were strongly dependent on enzymatic activity, while dolomite fertilization resulted in a significant increase in biomass size in the fir trees included in this study. In addition to being associated with the highest plant biomass and amounts of enzymatic activity, dolomite-fertilized soil also had the highest number of fungal operational taxonomic units (OTUs): 403, compared to 322 OTUs in the control soil. Finally, the fungal communities in the control soil varied significantly from the fungal communities in soils fertilized with dolomite and serpentinite. The results of this research support mineral fertilization, and in particular, fertilization using dolomite in amounts of 4000 kg.ha-1, to improve soil nutrient supply and to shape the biological activity expressed by the enzymatic activity of forest soils.

Linking the contents of hydrophobic PAHs with the canopy water storage capacity of coniferous trees.

The canopy water storage capacity (S) is an important parameter for the hydrological cycle in forests. One factor which influences the S is leaf texture, which in turn is thought to be affected by the contents of polycyclic aromatic hydrocarbons (PAHs). In order to improve our understanding of S we simulated rainfall and measured the S of coniferous species growing under various conditions. The contents of 18 PAHs were measured in the needles. The species chosen were: Scots pine (Pinus sylvestris L), Norway spruce (Picea abies (L.) H. Karst) and silver fir (Abies Alba Mill.). Sample branches were collected in 3 locations: A - forest; B - housing estate; C - city center. We found that PAHs have a significant impact on the S of tree crowns. The increase in the total content of all of polycyclic aromatic hydrocarbons (SUM.PAH) translates into an increase of S for all species. The S is the highest for the P. abies species, followed by P. sylvestris and A. alba at all locations. Within the same species, an increase in the value of S is associated with an increase in the PAH content in needles measured by gas chromatography. For A.alba, the average S increased from 11.54% of the total amount of simulated rain (ml g-1) at location A, to 17.10% at location B, and 21.02% at location C. Similarly for P. abies the S was 21.78%, 29.06% and 34.36% at locations A, B and C respectively. The study extends the knowledge of the mechanisms of plant surface adhesion and the anthropogenic factors that may modify this process as well as foliage properties.

Polycyclic Aromatic Hydrocarbons Content in Contaminated Forest Soils with Different Humus Types.

The aim of the study was to determine polycyclic aromatic hydrocarbon (PAH) content in different forest humus types. The investigation was carried out in Chrzanów Forest District in southern Poland. Twenty research plots with different humus types (mor and mull) were selected. The samples for analysis were taken after litter horizons removing from a depth of 0-10 cm (from the Of- and Oh-horizon total or A-horizon). pH, organic carbon and total nitrogen content, base cations, acidity, and heavy metal content were determined. In the natural moisture state, the activity of dehydrogenase was determined. The study included the determination of PAH content. The conducted research confirms strong contamination of study soil by PAHs and heavy metals. Our experiment provided evidence that different forest humus types accumulate different PAH amounts. The highest content of PAHs and heavy metals was recorded in mor humus type. The content of PAHs in forest humus horizon depends on the content and quality of soil organic matter. Weaker degradation of hydrocarbons is associated with lower biological activity of soils. The mull humus type showed lower content of PAHs and at the same time the highest biological activity confirmed by high dehydrogenase activity.

Influence of Oil Contamination on Physical and Biological Properties of Forest Soil After Chainsaw Use.

Forestry works using chainsaws result in up to 7 million liters of various mineral oils being soaked annually into forest soils. These substances, containing a complex mixture of polycyclic aromatic hydrocarbons (PAHs), are highly toxic. The aim of the study was to determine the effect of oil contamination with PAHs on the physical and biological properties of forest soils. The study area was located in southern Poland in the Miechów forest district. The experiment was conducted on four treatment blocks with various amounts of oil addition. The study included the determination of PAH content, dehydrogenase and urease activity, and biomass of earthworms. Physical properties were determined using the dryer method and Kopecky rings of 250 cm3 volume. The results obtained confirmed the hypothesis that oil contamination with PAHs modified the physical properties of forest soils and oil had a negative impact on enzyme activity in soil. Enzyme activity in the studied soils was negatively correlated with PAH content. Earthworm population density reflected the contamination level of oil-contaminated soils.

Effect of variable soil texture, metal saturation of soil organic matter (SOM) and tree species composition on spatial distribution of SOM in forest soils in Poland.

In this study we investigated the effect of fine (ϕ<0.05mm) fraction, i.e., silt+clay (FF) content in soils, site moisture, metal (Al and Fe) of soil organic matter (SOM) and forest species composition on the spatial distribution of carbon (C) pools in forest soils at the landscape scale. We established 275 plots in regular 200×200m grid in a forested area of 14.4km(2). Fieldwork included soil sampling of the organic horizon, mineral topsoil and subsoil down to 40cm deep. We analysed the vertical and horizontal distribution of soil organic carbon (SOC) stocks, as well as the quantity of physically separated fractions including the free light (fLF), occluded light (oLF) and mineral associated fractions (MAF) in the mineral topsoil (A, AE) horizons. Distribution of C in soils was predominantly affected by the variation in the FF content. In soils richer in the FF more SOC was accumulated in mineral horizons and less in the organic horizons. Accumulation of SOC in mineral soil was also positively affected by the degree of saturation of SOM with Al and Fe. The increasing share of beech influenced the distribution of C stock in soil profiles by reducing the depth of O horizon and increasing C stored in mineral soil. The content of FF was positively correlated with the content of C in MAF and fLF fractions. The content of oLF and MAF fractions was also positively influenced by a higher degree of metal saturation, particularly Al. Our results confirmed that Al plays an important role in the stabilization of SOM inside aggregates (CoLF) and as in CMAF fractions. We also found a significant, positive effect of beech on the CfLF and fir on the CoLF content.