Volume 21 Issue 2

Mountain ecosystems are under increasing pressure from forest degradation, which can alter key ecological indicators, including herbaceous biomass production. This study considered how herbaceous above-ground biomass (AGB) is influenced by degradation intensity, nitrogen availability, elevation, and species richness in temperate and subtropical forests of the Hindu Kush Himalayas. Data from 200 systematically placed plots were analyzed using bivariate and correlation methods, followed by structural equation modeling (SEM) to assess both direct and indirect pathways affecting herbaceous biomass. The results showed that available nitrogen was the strongest predictor of biomass (β = 0.77, p < 0.001), followed by species richness (β = 0.18, p < 0.05). Degradation reduced biomass indirectly by decreasing nitrogen (β = -0.72, p < 0.001) and species richness (β = -0.59, p < 0.001). Moderate degradation also negatively influenced subtropical habitat (β = -0.82, p < 0.001) and nitrogen (β = -0.43, p < 0.01). Higher nitrogen levels were significantly associated with less degradation (β = -0.47, p < 0.001), suggesting a protective effect of nitrogen-rich soils. Elevation had no direct effect on biomass but reduced subtropical forests (β = -0.82, p < 0.001) and increased moist temperate forests (β = 0.35, p < 0.01). The model identified nitrogen as the main driver of productivity, while degradation disrupted soil fertility and biodiversity, especially in vulnerable low-elevation forests.

Mechanical behavior was tested for hybrid composites with natural luffa fiber and artificial woven carbon fabrics within an epoxy matrix with orientation angles of [90°], [45°], and [0/90°]. Specimens were produced with artificial and natural fibers in a four-layer configuration. Three-point bending, tensile, and low-speed impact tests were applied. In tensile tests, specimen [0/90º Carbon – Luffa – Luffa – 0/90º Carbon] exhibited the highest strength, reaching approximately 42 MPa. In three-point bending tests, specimen [0/90º Carbon – Luffa – Luffa – 0/90º Carbon] showed the highest force of approximately 120 N. In low-speed impact tests, at an impact energy of 5 J, the impactor rebounded without penetrating any of the specimens. At an impact energy of 15 J, punctures and fiber damage occurred in samples [90º Carbon – Luffa – Luffa – 90º Carbon] and [45º Carbon – Luffa – Luffa – 45º Carbon]. In contrast, sample [0/90º Carbon – Luffa – Luffa – 0/90º Carbon] reached maximum force values of approximately 6000 N at 15 J impact energy and approximately 3500 N at 5 J impact energy, exhibiting higher impact resistance without puncture. Based on these results, the woven carbon fabric orientation angle had a decisive effect on the bending, tensile, and impact behavior of hybrid composites.

This study investigated the changes in the chemical composition of Rowan (Sorbus torminalis L.) when subjected to heat treatment (HT) and cryogenic treatment (Cr). Rowan wood was treated with HT at two different temperatures (190 and 212 °C) and times (1 and 2 hours). Subsequently, Cr was applied to some of the HT samples and a control sample (Control), creating a total of 8 experimental variations. The content of lignin, holocellulose, alpha-cellulose, ash, and the solubilities of hot water, 1% NaOH, and acetone, were determined. The control and the samples treated with HT and Cr showed differences in most of the investigated properties. For example, the amount of lignin in the samples increased as the HT temperature and time increased (maximum increase of 94.5%). However, Cr was found to limit this increase. Hemicelluloses were the most degraded components during HT, while the degradation of alpha-cellulose was much more limited. In contrast, Cr slightly increased the amounts of hemicelluloses and alpha-cellulose in the heat-treated samples. While HT (212 °C, 2 h) increased the amount of extractives by 2.3 times, Cr caused a decrease in the Control, but greatly reduced this increase in other samples.

The transition to circular bioeconomy in the European Union prioritizes efficient wood resource utilization and waste reduction. This study investigated interrelationships among production of sawnwood and particleboard, as well as intra- and extra-EU wood waste trade from 2004 to 2023 to evaluate alignment with sustainability and climate policy objectives. Eurostat data were analyzed using correlation, cross-correlation, and regression analyses. Sawnwood production peaked at 113.1 million cubic meters in 2007 and declined to 88.3 million cubic meters in 2023. Particleboard production decreased from 80.3 to 52.2 million cubic meters over the same period. Wood waste generation reached 63.1 million tonnes in 2008 and fell to 46.8 million tonnes in 2022, during which time the wood processing sector reduced waste by nearly 68%. No consistent relationship was identified between sawnwood production and internal wood waste trade, nor between internal waste trade and particleboard production. Imports of wood waste demonstrated delayed positive effects on production, and a moderate positive relationship was observed between internal waste trade and waste imports. Using wood residues for energy recovery limits its availability for higher value applications. These findings emphasize the necessity for policies that balance renewable energy targets with long-term material circularity.

This study presents a sustainable and cost-effective approach for treating olive mill wastewater (OMWW) using activated carbon derived from olive pomace, a major by-product of olive oil production. The proposed system integrates the production of this adsorbent with wastewater treatment in a two-stage, circular process that combines acid precipitation and adsorption. The prepared activated carbon exhibited a well-developed porous structure and high iodine value (948 mg/g), enabling efficient removal of phenolic compounds from OMWW. The results showed removal efficiencies exceeding 99% for phenolic compounds, along with significant reductions in key pollutants, including chemical oxygen demand and total organic carbon. It was hypothesized that integrating waste valorization with wastewater treatment can enhance both environmental and economic performance. The findings confirmed this hypothesis, demonstrating high treatment efficiency and substantial cost reduction through process optimization, including reduced adsorbent dosage and reuse. Process optimization, including reduced adsorbent dosage and reuse, led to a substantial decrease in treatment costs. Overall, this study demonstrated that integrating waste valorization with wastewater treatment offers an effective and practical solution for environmental management. The findings highlight the potential of olive pomace-derived activated carbon as a low-cost and sustainable adsorbent for large-scale applications.

An eco-friendly one-pot approach was employed to biosynthesize selenium oxide/zinc oxide (SeO/ZnO) nanocomposites using banana peel (Musa acuminata L.) extract. The phytogenic nanocomposite was characterized using FTIR, UV–Vis spectroscopy, TEM, SEM, and EDX analyses. A distinct absorbance peak at 336 nm confirmed nanocomposite formation, while FTIR results indicated the involvement of plant phytochemicals in stabilization and surface functionalization processes. TEM images revealed quasi-spherical nanoparticles with an average diameter of 64 nm. Elemental analysis (EDX) confirmed the presence of selenium and zinc, suggesting that selenium is predominantly present in oxide form (SeO) within the ZnO matrix. Biological evaluations showed significant multifunctional activity. The SeO/ZnO nanocomposite exhibited selective antiproliferative activity against A549 lung cancer cells (IC₅₀ = 100.9 µg/mL) compared to normal Vero cells (IC₅₀ = 263.5 µg/mL), indicating favorable selectivity. Pronounced antibacterial activity was observed, particularly against Bacillus subtilis (MIC = 62.5 µg/mL; inhibition zone = 27.8 ± 0.75 mm). Concentration-dependent antioxidant activity was confirmed using DPPH and ABTS assays, with IC₅₀ values of 256.8 and 339.40 µg/mL, respectively.

Increasing the use of chemical fertilizers to keep pace with the continuous increase in population leads to deterioration of soil fertility, air and groundwater pollution, and the disruption of beneficial microbes. Therefore, there is a necessity to use biostimulants. Biostimulants are valuable for sustainable fruit crop production, boosting growth and plant health. Used with fertilizers, they improve nutrient efficiency and resilience, supporting productivity and environmental goals. Biostimulants promote the blooming, development, and yield of fruit plants. The current study was conducted on navel orange trees cv. Washington grafted on Volkmeriana rootstock during the 2024 and 2025 seasons to investigate the influence of the spraying of yeast extract (YE) at 0.1, 0.2, and 0.3%, vermicompost tea (VCT) at 2, 4, and 6%, and their combinations: 0.1% YE + 2% VCT; 0.2% YE + 4% VCT; 0.3% YE + 6% VCT, compared to trees that were not sprayed. The trees were sprayed three times: before flowering in March, during full bloom, and one month after the second spraying. The results showed that spraying YE, VCT, and their combinations significantly improved vegetative growth parameters, yield, fruit physical and chemical characteristics, and leaf macro- and micronutrient mineral content compared with non-sprayed trees in both seasons.

The proximate compositions of seaweeds, namely Sargassum boveanum, Padina gymnospora, and Dictyota dichotoma, were analyzed. The dried powder was further extracted via ethanol, acetone, ethyl acetate, and chloroform, and the phenolic and flavonoid contents of the extracts were determined. The ethanolic extracts presented greater yields than the other solvents did, and the values ranged from 5.1±0.9 to 25.2±1.3, 2.2±0.4 to 35.3±1.1, and 3.3±0.5 to 20.6±1.2, for S. boveanum, P. gymnospora, and D. dichotoma, respectively. The highest total flavonoid and phenolic contents were found in the ethyl acetate extract of P. gymnospora, with values of 91.5±1.2 mg QE/g and 178.3±1.1 mg GAE/g, respectively. The 2,2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging assay, ferric reduction activity powder (FRAP) assay, and ABTS method were used. The ethyl acetate extract of P. gymnospora presented the maximum DPPH activity (65.3±1.1 TE/g), whereas the ethanol extract presented 27.6±0.5 AAE/g in the FRAP assay, and the ethyl acetate extract presented 37.3±0.8 TE/g activity. The ethyl acetate extract of P. gymnospora presented higher α-amylase inhibitory activity (0.28±0.04 mg/mL), whereas the ethanol extract of S. boveanum presented higher α-glucosidase inhibitory activity (0.31±0.02 mg/mL). The maximum human red blood cell protection activity (43.7±1.2%) and cyclooxygenase enzyme -2 inhibition(37.1±0.2%) activity were observed in the ethyl acetate fraction of S. boveanum.

Direct and indirect photolysis are the primary fate pathways of natural organic matter (NOM) impacting the global carbon cycle in surface soils.  For NOM, opposite trends in structural changes are often observed between photolytic and dark aerobic transformations.  Industrial organic byproducts are generated under more controlled conditions than NOM, and their photochemical fate is largely unknown.  This study employed optical methods (fluorescence, UV/visible) to trace the changes in conjugated structures of sugar processing byproduct (mill mud) for 2 wk.  After an initial (≈1 wk) lag period, photolysis became dominant over dark reactions. Photolysis increased the aromaticity (higher emission wavelength peaks) and estimated amount (higher fluorescence intensity) of chromophores, and the effects were greater for pristine than aged mill mud.  However, field aging of mill mud transformed reactive chromophores into stable aromatic structures with characteristic ≈400 nm emission that were resistant to photolysis or dark reaction.  Factory mill mud showed similar fate pathways as NOM.  Anaerobic incubation in dark formed absorbance peaks at 280 and 320 nm typically observed in NOM.  Slope ratios for those peaks were decreased by photolysis, indicating the formation of aromatic structures.  In summary, visible range irradiation is sensitive to conjugated double bonds, and could be used to add values to industrial byproducts, and to evaluate their fate as a soil amendment.

Torrefied sawdust has gained attention as a carbon-rich material with enhanced porosity and adsorption properties, making it a promising candidate for ethylene scavenging to extend fruit shelf life. In this study, torrefied oak sawdust was mixed with vermiculite to prepare ethylene scavenger mixtures, and their adsorption performance and effects on fruit quality were systematically evaluated. Laboratory-scale measurements showed that increasing the proportion of torrefied sawdust significantly enhanced ethylene adsorption. Response surface methodology (Box–Behnken design) identified optimal preparation conditions (66% torrefied sawdust, 2 mm particle size, and 342 h exposure) yielding an adsorption efficiency of approximately 84%. Compared with pure vermiculite, the optimized mixture provided substantially higher ethylene removal capacity and contributed to more than a two-fold extension of apple shelf life during storage. These findings highlight the potential of torrefied sawdust–based mixtures as effective, low-cost ethylene scavengers for postharvest fruit preservation and provide valuable design parameters for future material optimization.