Search Results (84)

In the ecologically fragile western Shanxi Loess region, stand density regulation of artificial Robinia pseudoacacia L. forests plays a crucial role in sustaining the water regulation functions of the litter-soil system, yet multi-scale mechanistic analyses remain scarce. To address this gap, we established six stand density classes (ranging from 1200 to 3200 stems/ha) and quantified litter water-holding traits and soil physicochemical properties. We then applied principal component analysis (PCA) and structural equation modeling (SEM) to examine density-litter-soil relationships. Low-density stands (≤2000 stems/ha) exhibited significantly higher litter accumulation (6.08–6.37 t/ha) and greater litter water-holding capacity (maximum 20.58 t/ha) than the high-density stands (p < 0.05). Soil capillary water-holding capacity decreased with increasing density (4702.63–4863.28 t/ha overall), while non-capillary porosity (5.26–6.21%) and soil organic carbon (~12.5 g/kg) were higher in high-density stands (≥2800 stems/ha), reflecting a structural-carbon optimization trade-off. PCA revealed a primary hydrological function axis with low-density stands clustering in the positive quadrant, while high-density stands shifted toward nutrient-conservation traits. SEM confirmed that stand density affected soil capillary water-holding capacity indirectly through litter accumulation (significant indirect path; non-significant direct path), highlighting the central role of litter quantity. When density exceeded ~2400 stems/ha, litter decomposition rate decreased by ~56%, coinciding with capillary porosity falling below ~47%, a threshold linked to impaired balance between water storage and infiltration. These findings identify 1200–1600 stems/ha as the optimal density range; in this range, soil capillary water-holding capacity reached 4788–4863 t/ha, and available phosphorus remained ≥2.1 mg/kg, providing a density-centered, near-natural management paradigm for constructing “water-conservation vegetation” on the Loess Plateau. Full article

The availability of detritus is a key factor influencing aquatic biota and can significantly affect decomposition processes. In this study, we investigated how varying quantities of surrounding detritus impact leaf litter decay rates. It was tested in flowing and still-water microcosms to highlight context-dependent effects of surrounding detritus on leaf litter decomposition. To isolate the effect of detritus amount, experiments were conducted in laboratory microcosms simulating lotic and lentic ecosystems, each containing leaf fragments for decomposition assessments. Four detritus quantities were tested, with invertebrates either allowed or restricted from moving among detritus patches. Leaf decomposition rates were influenced by the amount of surrounding detritus, with slower decay observed at higher detritus conditions, regardless of invertebrate mobility. Detritivore distribution responded to both detritus quantity and oxygen availability, showing a preference for high detritus conditions. Additionally, detritus quantity affected microbial activity with a quadratic response, as indicated by leaf respiration rates. Overall, our findings indicate that the amount of surrounding detritus modulates leaf litter decomposition independently of invertebrate density, by influencing oxygen dynamics and, consequently, the activity of biological decomposers. Full article

The trial explored innovative low-protein diets for weaning piglets, testing the elimination of fish meal and blood derivatives. The trial compared three treatments, each with two post-weaning feeds: control feed with blood plasma and fishmeal; T1: low-protein feed with seven amino acids, fishmeal, and blood plasma; T2: low-protein feed with seven amino acids without fishmeal and blood plasma. The trial tested 180 weaned piglets, 24 days of age, evenly distributed by weight, age, and litter of origin. At the end of the first phase, T1 and T2 recorded a significantly higher average weight, ADG, and FCR compared with the control feed. At the end of the second phase, the T2 group maintained a significantly better weight, ADG, and FCR than the control group. Considering the entire test period (phase 1 and phase 2), the T2 thesis appears to have a significantly higher average weight, ADG, with a lower FCR compared to the control group. The T2 thesis fixed a significantly (p < 0.01) greater quantity of nitrogen compared to the T1 thesis and control feed (T2 58.71% vs. T1 54.13% and control 54.02%). In conclusion, a low-protein diet without raw materials of animal origin proved more efficient in terms of performance and nitrogen retention. Full article

The quantity, quality, and accumulation rate of plant litter play a key role in forest floor flammability and, by extension, fire regimes. The varying foliage properties of different tree species also determine litter’s decomposition and its accumulation on the forest floor. The removal of litter by soil fauna, i.e., bioturbation, depends on both the dominant tree species and the successional stage of the forest stand. This research involved laboratory mesocosm experiments aiming to determine the effects of litter quality and earthworm activity on the flammability of the forest floor material at different successional ages. The mesocosms simulated the planting of four tree species (the broadleaf species Alnus glutinosa (L.) Gaertn. (Black alder) and Quercus robur L. (English oak) and the conifers Picea omorika (Pančić) Purk. (Serbian spruce) and Pinus nigra J.F. Arnold (Austrian pine)) at a reclamation site near Sokolov (NW Czechia). The mesocosms contained litter from these different tree species, placed directly on overburden soil (immature soil) or on well-developed Oe and A layers (mature soil), inoculated or not inoculated with earthworms, and incubated for 4 months. The surface material in the mesocosms was then subjected to simulated burn events, and the fire path and soil temperature changes were recorded. Burn testing showed that litter type (tree species) and soil maturity significantly influenced flammability. Pine had longer burning times and burning paths and higher post-burn temperatures than those of the other tree species. The immature soil with earthworms had significantly shorter burning times, whereas in the mature soil, earthworms had no effect. We conclude that earthworms have a significant, immediate effect on the litter flammability of immature soils. Full article

Selective serotonin reuptake inhibitors (SSRIs), like fluoxetine, are increasingly used by women of a reproductive age, raising concerns about their impact on oocyte quality and early embryonic development. This study investigated the effects of chronic fluoxetine exposure on oocyte maturation, ovulation, and embryonic development in a mouse model. Female mice were administered fluoxetine via drinking water, and their reproductive outcomes were compared to those of control mice. Oocyte quantity and quality were assessed following superovulation, including the analysis of spindle morphology, chromatin configuration, and maturation markers. In vitro maturation assays were conducted to evaluate the developmental competence of oocytes exposed to fluoxetine. Finally, the impact of fluoxetine on blastocyst formation, litter size, offspring growth, and ovarian reserve was examined. The results show that fluoxetine treatment reduced the number of ovulated oocytes but did not significantly affect oocyte quality or meiotic spindle formation. Fluoxetine exposure impaired cytoplasmic maturation at the germinal vesicle stage, resulting in a lower proportion of fully mature oocytes and reduced in vitro maturation efficiency. While blastocyst numbers were modestly reduced in fluoxetine-treated mice, litter size and offspring ovarian reserve were unaffected. Unexpectedly, offspring of fluoxetine-treated mothers exhibited increased body weight. These findings suggest that while fluoxetine may impair oocyte developmental competence through disruptions in cytoplasmic maturation, it does not severely compromise overall reproductive outcomes or offspring fertility. Full article

Rearing broiler chickens generates large quantities of waste material in the form of bedding. Anaerobic digestion (AD) is a technology that can be applied to this waste. This study aimed to evaluate the AD of broiler litter, either screened (S) or unscreened (US), from different flocks, collected from each production batch, totaling nine, from a commercial farm. Anaerobic digestion was conducted in batch biodigesters, and fraction separation was performed through screening prior to loading. The S substrate from the second and fifth flocks did not produce biogas. Reductions in total (TS) and volatile solids were highest for S substrates from the third flock (50.5% and 58.3%, respectively). Only the third flock’s S substrates showed greater reductions in solids than the US substrates. Potential biogas and methane production were also highest in the third flock’s bedding for both the S substrate (336.8 and 218.2 L/kg of TS, respectively) and the US substrate (296.8 and 213.4 L/kg of TS, respectively). The methane concentration in the S substrate was highest in the third flock (64.8%), while in the US substrate, it was highest in the third and fourth flocks (70.3%). Screening the litter reduced the process efficiency. We conclude that fraction separation is inadvisable for broiler litter. Full article

Marine litter (ML), encompassing human-made objects in marine ecosystems, poses significant threats to the coasts of some Adriatic islands, despite their remoteness and sparse populations. These islands, reliant on tourism, are particularly vulnerable to ML pollution. This study hypothesized that the natural features of the islands influence ML distribution. It employes an integrated geographic approach combining the results of field survey (via sea kayaking) with various indicators which include: (1) coastal orientation and number density of bays, (2) vegetation exposure and biomass share, (3) island area and number density of bays, (4) bay openness and ML quantity, and (5) bay openness and plastic prevalence in ML. Focusing on islands of Lošinj, Pašman, Vis, and the Kornati and Elaphiti archipelago, the study analyzed data collected over six years (2018–2023). Results highlighted that NW-SE and W-E coastal orientations are particularly susceptible to ML accumulation, especially in the southern Adriatic. Linear Fitting Regression analyses revealed a stronger correlation between number density of polluted bays and the surface area of smaller islands (<10 km²) compared to larger islands (>10 km²). The following findings underscore the need for international collaboration and stringent policies to mitigate ML pollution, ensuring the protection of Adriatic marine ecosystems and the sustainability of local communities. Full article

Land use patterns significantly influence the quantity and composition of litter in the soil humus layers, thereby affecting the dynamics of soil organic carbon. However, the differences in labile organic carbon fractions and the carbon sequestration index under different land use patterns, as well as their impact on soil carbon storage in the humus layers of mollisols—without migration loss and soil erosion—remain unclear. Labile organic carbon is classified into fractions such as dissolved organic carbon, easily oxidized carbon, particulate organic carbon, and microbial biomass carbon, which are identified through different chemical extraction methods. This study investigates the impact of long-term land use patterns on organic carbon dynamics, organic carbon pools, K_OS, and CPMI in mollisols across five treatments: SC (continuous soybean cultivation), MC (continuous maize cultivation), MSR (maize–soybean rotation), GB (grass belt), and FB (forest belt). It also selects three soil depths (0–20 cm, 20–40 cm, and 40–60 cm) over an 11-year period for analysis. The results indicate that soil organic carbon, labile organic carbon fractions (EOC, POC, DOC, and MBC), and CPMI decrease with soil depth, while K_OS increases. Non-tillage treatments enhance SOC accumulation in the humus layers, with FB exhibiting the highest organic carbon content, surpassing GB, MC, SC, and MSR by 22.88%, 52.35%, 60.64%, and 80.12%, respectively. Non-tillage treatments can enhance the accumulation of labile organic carbon fractions, aligning with the observed trends in soil organic carbon, with the FB treatment identified as optimal. Additionally, these treatments can increase labile organic carbon fractions and CPMI, thereby improving soil stability. To minimize SOC loss, land use patterns should encourage the conversion of farmland to grassland and forest, with the FB treatment recommended as the optimal strategy for the protection of mollisols and the sustainable development of these soils over the long term. This approach is significant for understanding the soil carbon cycle, rationally planning land use strategies, and providing a reference for enhancing soil quality and ecosystem carbon sinks. Full article

The growth of the global population, coupled with concomitant economic development, has resulted in the generation of a substantial quantity of waste. The transition of the European Union’s economy towards a closed-loop model is prompting a comprehensive search for waste management concepts across a range of industrial sectors. The objective of this study is to valorise deinking paper sludge, which has a high potential for soil formation due to its high organic matter content. To produce organic–mineral fertiliser, the deinking sludge was subjected to acid hydrolysis, then neutralised with KOH solution and enriched with poultry litter ash. The final products were characterised in terms of their nutrient and heavy metal content. The bioavailability of phosphorus, along with the forms in which it occurs in fertilisers, was determined through the implementation of a five-step fractionation procedure. Furthermore, an eight-week incubation period was conducted to assess the fertilisers’ performance in soil. Soil samples were tested on a weekly basis for pH, water-soluble and bioavailable phosphorus content using the spectroscopic method after previous extraction in water and Bray’s solution, and catalase activity using the titrimetric method. The resulting fertilisers were found to meet the requirements for organo-mineral fertilisers and were categorised as PK-type fertilisers with a total nutrient content of 24.6–39.3%. Fractionation studies demonstrated that the fertilisers contained 20–30% of the total potentially bioavailable phosphorus. Furthermore, the long-term release of phosphorus from the fertilisers was confirmed through incubation studies. Additionally, the fertilisers were observed to contribute to an increase in catalase activity in the soil. Full article

The Mar Piccolo is a transitional water system located in Taranto city (Southern Italy); it is a semi-enclosed basin affected by severe pollution issues due to the presence of various industrial, agricultural and other anthropic activities that require careful monitoring and management. The pollution levels reached over time have harmed marine biodiversity and human health, repeatedly requiring timely actions for its mitigation. Characterization methodologies and techniques today play a fundamental role in supporting the decision-making phase, processing large quantities of data and identifying complex patterns and correlations. An approach focused on gaining detailed knowledge of complex environmental contexts through clustering map techniques enables highly precise results, capturing even the smallest variations in the features of the study object and strongly correlating them with possible sources of pollution. The use of these techniques improves the precision of the analyses and can significantly contribute to improving the understanding of the environmental state in the Mar Piccolo area. This study addresses the issue of pollution in Mar Piccolo due to marine litter, which has led to the formation of synanthropic habitats on the seabed. It also highlights the value of clustering maps and other characterization techniques for achieving detailed insights at various levels of analysis. Data processing through the proposed methodology can generate very detailed mapping useful for planning precision reclamation interventions that also include species conservation actions, as well as a better understanding of how synanthropic habitats are distributed and evolve. In summary, this study demonstrates how it is possible to improve the precision of data processing, providing crucial details for the management and conservation of highly threatened marine ecosystems. Full article

The impact of nitrogen and phosphorus deposition alternations, as well as apoplastic litter quality and quantity, on soil nutrient cycling and soil carbon pool processes in forest ecosystems is of considerable importance. Soil ecological enzyme chemistry is a powerful tool for elucidating the nutrient limitations of microbial growth and metabolic processes. In order to explore the responding mechanisms of soil ecological enzyme chemistry to the simultaneous changes in apoplast input and nitrogen and phosphorus deposition in temperate coniferous and broad-leaved mixed forests, an outdoor simulating experiment was conducted. The results demonstrate that the treatments involving apoplastic material and nitrogen and phosphorus additions had significantly impacted soil nutrient levels across different forest types. Apoplastic treatments and N-P additions had a significant effect on the soil total organic carbon (TOC), dissolved organic carbon (DOC), soil total soluble nitrogen (TSN), soil available phosphorus (SAP), soil total nitrogen (TN), soil total phosphorus (TP), and microbial biomass carbon (MBC). However, the effects on soil microbial biomass (MBN) and microbial biomass phosphorus (MBP) were insignificant. The apomictic treatments with N and P addition did not result in a statistically significant change in soil C-hydrolase activities (β-1,4-glucosidase BG, β-1,4-xylosidase BX, cellobiohydrolase CBH, phenol oxidase POX, and peroxidase PER), N-hydrolase activities (β-1,4-N-acetylglucosaminidase NAG and L-leucine aminopeptidase LAP), or P-hydrolase activities (Acid phosphatase AP). Although the apomictic treatments did not yield a significant overall impact on carbon hydrolase activity, they influenced the activity of specific enzymes, such as CBH, LAP, and PER, to varying degrees. The effects on BG, BX, CBH, AP, and C-hydrolase activities were significant for different stand types. The impact of apomictic treatments and N-P additions on soil nitrogen hydrolase activities was inconsequential with a minimal interactive effect. The highest correlation between PER, LAP, and N-hydrolase activities was observed in conjunction with elevated levels of nitrogen and phosphorus addition (N3L0, original litter treatment, and high amounts of N and P addition). These findings may provide a theoretical foundation for the management of ecosystem function in broad-leaved Korean pine forests. Full article

Our research assesses the effects of four forest species, namely, Swietenia macrophylla King, Swietenia mahagoni (L.) Jack., Pinus occidentalis Swartz, and Pinus caribaea Morelet var. Caribaea, on the soil and litter organic carbon (C) stocks, C dioxide equivalent balance (BCO₂ Eq.) diurnal, and periodic dynamics beneath these species. Reforestation projects in the study region cover 1200, 543, 770, and 1152 hectares, respectively, with these four species being the most relevant in reforestation projects within the country. To determine the BCO₂ Eq. per unit area, we compared the greenhouse gas (GHG) fluxes of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) expressed as CO₂ Eq. units with the organic C stocks found in the mineral soil to a depth of 30 cm and in the forest litter. In four measurement periods over 18 months, we conducted field measurements in sixteen stands, four per species. Our results indicate that S. mahagoni emitted the lowest CO₂ Eq., while S. macrophylla released the highest amount into the atmosphere. At the end of the 18 months, BCO₂ Eq. from S. macrophylla soils was 299.70 metric tons ha⁻¹ year⁻¹, while for P. occidentalis, P. caribaea, and S. mahagoni, the corresponding quantities were 103.64, 146.41, and 72.34, respectively. All species showed a general upward pattern in soil respiration from September 2020 to March 2022. The average CO₂ Eq. flux rates to the atmosphere were approximately 65.4, 51.1, and 75.9 percent higher in S. macrophylla soils compared to the respective rates of P. occidentalis, P. caribaea, and S. mahagoni. Full article

This study investigates plastic litter on two beaches in Malta, Golden Bay and Rivera Beach, with a focus on plastic abundance, characteristics, sources, and the influence of human activity on pollution levels. Conducted in March 2023 during the low-tourist season, 13 sediment samples were collected from a depth of 5 cm using a systematic square sampling method. Plastic litter was quantified and sorted by size, shape, color, and polymer type, and concentrations of potentially toxic elements (PTEs) were measured (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe via ICP-OES). Golden Bay exhibited significantly higher plastic quantities (53.9 ± 4.3 n/m²) compared to Rivera Beach (29.7 ± 4.0 n/m²). Microplastics were dominant on both beaches, with Golden Bay showing a higher proportion (57.0%) than Rivera Beach (50.6%). The plastic litter predominantly consisted of PE (59.6–68.0%) and PP (29.6–38.8%). Golden Bay plastics had PTE concentrations up to 4.9 times higher than those in Rivera Beach, notably for Mn (309.0 μg/g vs. 63.1 μg/g). This research contributes valuable insights into the dynamics of plastic pollution in coastal environments, particularly in areas influenced by tourism. Full article

Soil organic matter (SOM) is essential for nutrient cycling and soil carbon (C) accumulation, both of which are heavily influenced by the quality and quantity of plant litter. Since SOM dynamics in relation to plant diversity are poorly understood, we investigated the effects of willow variety and mixture, and site on the soil C stocks, SOM chemical composition and thermal stability. Using pyrolysis-field ionization mass spectrometry (Py-FIMS), a method of stepwise thermal degradation in ultrahigh vacuum combined with soft ionization in a high electric field, followed by mass-spectrometric separation and detection of molecular ions, we analyzed SOM in the top 10 cm of soil from two 7-year-old experimental sites in Germany and Sweden. Monocultures and mixtures of two willow varieties (Salix spp.) belonging to different species were grown at the experimental plots. Overall, site had the strongest effect on SOM quality. The results showed significant variability across sites for willow identity and mixture effects on C accumulation and SOM chemistry. In the German site (Rostock), yearly soil C accumulation was higher (p < 0.05) for variety ‘Loden’ (1.0 Mg C ha⁻¹ year⁻¹) compared to ‘Tora’ (0.5 Mg C ha⁻¹ year⁻¹), whilst in the Swedish site (Uppsala), both varieties exhibited similar soil C accumulation rates of around 0.6 Mg C ha⁻¹ year⁻¹. Willow variety identity significantly affected SOM quality at both sites, while mixing had minor effects. Our findings emphasize the significance of site-specific context and variety and species identity in shaping soil C accumulation in willow plantations. Full article

Microplastics (MPs) are present in ambient air in a respirable size fraction; however, their potential impact on human health via inhalation routes is not well documented. In the present study, methods for a lab-scale generation of MPs from regularly used and littered plastic articles were optimized. The toxicity of 11 different types of MPs, both commercially purchased and in-lab prepared MPs, was investigated in lung epithelial cells using cell viability, immune and inflammatory response, and genotoxicity endpoints. The underlying mechanisms were identified by microarray analysis. Although laborious, the laboratory-scale methods generated a sufficient quantity of well characterized MPs for toxicity testing. Of the 11 MPs tested, the small sized polyethylene terephthalate (PETE) MPs prepared from disposable water bottles induced the maximum toxicity. Specifically, the smaller size PETE MPs induced a robust activation of the interferon signaling pathway, implying that PETE MPs are perceived by cells by similar mechanisms as those employed to recognize pathogens. The PETE MPs of heterogenous size and shapes induced cell injury, triggering cell death, inflammatory cascade, and DNA damage, hallmark in vitro events indicative of potential in vivo tissue injury. The study establishes toxicity of specific types of plastic materials in micron and nano size. Full article