环境•农林最新文献

Urban areas worldwide face significant challenges from increasing air pollution, posing health risks and environmental concerns. Lahore, a major city in Pakistan, is particularly affected by severe air pollution due to rapid industrial growth, high vehicle emissions, and various human activities. Traditional air quality monitoring methods, while effective, are often costly and complex, limiting their widespread use. This study investigates a dual monitoring system combining passive biomonitoring with spider web silk and active measurements using portable instruments to assess airborne pollutants in urban environments. Spider webs, collected from various sites in Lahore, were analyzed for heavy metals, while portable instruments simultaneously measured PM_2.5, PM₁₀, total volatile organic contents, formaldehyde, and carbon monoxide at the same locations. A spatial distribution analysis using GIS and statistical analysis revealed a pattern with significant changes as per land use in the urban environment related to anthropogenic activities. The Principal Component Analysis revealed three distinct clusters of pollutants origins consisting of: I) effluent drains and landfills, II) construction sites, and III) residential areas. The concentrations of Hg in spider silk (average ~ 2.66 mg/kg) were found to be significantly higher in the northeastern part of Lahore, with a similar trend observed in Cd, Cu, Ni, and As levels (average ~ 15.45, 102.87, 31.72, and 6.64, respectively). Several-fold changes in levels and spatial distribution of Pb (15.12 to 356.41 mg/kg) showed a higher concentration in the northern and northeastern parts of Lahore. The spatial variation pattern of Cr (average~ 57.04 mg/kg) registered a higher concentration in southwestern Lahore. Ambient air levels of measured pollutants followed almost similar patterns in spatial distribution. PM_2.5 and PM₁₀ measured higher levels (195 and 226 μg/m³, respectively) in the southwestern and northwestern areas, with a similar pattern of variation observed in TVOC (average ~ 0.14 μg/m³). The concentration of HCHO (average ~ 0.003 μg/m³) was higher in the southwest of Lahore. All measured pollutants registered higher values than air quality standards. Particulate matter is the most dominant pollutant contributing to air pollution (up to 20x higher than WHO guidelines). The findings support the use of a dual monitoring system, integrating passive spider web silk biomonitoring and active portable instruments, as a scalable and sustainable solution for air quality management. This approach holds potential for global application in diverse urban environments, with future research focusing on further validation and integration with advanced remote sensing technologies to enhance air quality monitoring and contribute to improved public health and environmental management worldwide. Hence, this research work points to the pote

Microplastics (MPs) are greatly released into soils in different ways, specifically through mulching practices in irrigated loess soils in northern Iran as the fertile and susceptible soils to water erosion. This study was conducted to examine the effects of Polyethylene (PE) (a common kind of MPs used in mulching farming in loess soils of north Iran), in a Loess soil under an experimental study. A loess soil was collected from 0- 30 cm surface and incubated at two levels of PE (2.5 and 5 % by weight) in two sizes (1-2 mm and >2mm) for 60 days, at 70% of field capacity moisture and temperature of 25-28 ° C. Soils samples were collected in 1, 15, 30, 45 and 60 days after incubation and different soil chemical, physical, mechanical and biological properties were measured. The results showed that soil pH was significantly (P<0.05) reduced by timing (time after incubation), and application rate of MPs. Inclusion of MPs led to increasing bulk density significantly (P<0.05) and also led to reducing aggregation and mean weight diameter (MWD) compared to control soil. The rate of MWD decreasing varied from 79 % to 87 % in different rates of MPs application. Among the mechanical attributes, liquid limit, plastic limit, and plastic index, all were reduced significantly (P<0.05) after mixing up and incubation with MPs. Reducing aggregation and aeration in treated soils compared to control soils, led to lowering soil microbial respiration, especially with timing. As our results about the effects of MPs in loess soils in a few cases were contrary to other soils studied worldwide, further studies are recommended to perform in loess soils in northern Iran, where receive considerable MPs by farming and open landfill practices in the studied region.

Heavy metals accumulate and bind strongly in soil, making them difficult to eliminate. The objective of this study was to evaluate the effect of alder buckthorn (Frangula alnus) and European hazelnut (Coryllus avellana) admixtures in pine monocultures on the accumulation and vertical distribution of heavy metals in soil surface horizons. Ten sites each of pine stands admixed with alder buckthorn, pine stands admixed with European hazelnut, and pine monocultures in the Rybnik Forest District in southern Poland were selected for each variant. For the study, soil samples were taken from each site from the organic and mineral horizons and analysed for N and C contents, C/N ratio, pHH₂O, base cation contents, and heavy metal contents. For all three stand compositions, the organic horizons showed a significant accumulation of heavy metals compared to the mineral horizons. Heavy metal content was correlated with pH, N and C contents, C/N ratio, and base cation contents. The admixture of shrubs, especially European hazelnut, positively affected soil organic matter quality and, consequently, the accumulation of heavy metals. European hazelnut had the most beneficial soil effects on the tested soil, which confirms that this species can be used in planning species composition, particularly in regions prone to heavy pollutant deposition.

Public data from sixty tropical rivers were used to explore variations in C, N, and P and the potential impact of anthropogenic activities over a decade on freshwater bodies. The results showed the Total Organic Carbon (TOC) varying between 2.7–73.0 mg C l⁻¹; whereas Total Nitrogen observations showed concentrations between 0.9 and 32.0 mg N l⁻¹ and Total Phosphorus showed a higher frequency of data in the range of 0.02–0.4 mg P l⁻¹. The annual total C load (TC) was estimated at 32.7 Tg C yr⁻¹, where dissolved inorganic carbon (DIC) accounted for 69% of TC and dissolved organic carbon (DOC) contributed 22%. The stoichiometry showed P depletion relative to C and/or N in 39 of the sixty rivers (65%). This was further supported by the fact that most catchments had TOC values > 50% (C/N/P = 100%). A significant trend was found for yearly fluxes of TOC for the period 2008–2018 (Mann–Kendall test; p = 0.0006; α = 0.05). Land-use and cover at period 2008–2018 indicated a trend of increasing anthropized area of 4%, whereas the natural area decreased by 3.1%. The organic load trend analysis showed 85% of municipalities with a positive trend, this high rate in the remaining organic load is indicative of urban and agricultural in the region.

Whether in ant-aphid mutualism the ants exert evolutionary selection pressure on aphid morphology has not yet been fully tested. Here, we tested whether the long proboscises of Stomaphis yanonis (Aphididae Lachninae) aphids confer an advantage in preventing predation by the tending ants. Specifically, we tested the hypothesis that aphids with a shorter proboscis would excrete less honeydew, making them more likely to be preyed upon by ants. Our results showed that aphid individuals with a shorter proboscis took up less phloem sap and excreted less honeydew than individuals with a longer proboscis. In addition, among aphids with a similar body size, those with a shorter proboscis were more susceptible to predation by ants than those with a longer proboscis. These results suggest that predation by tending ants, by exerting selection pressure on aphid proboscis morphology, has caused the aphids to evolve longer proboscises.