Impact assessment of skidding extraction: Effects on physical and chemical properties of forest soils and on maple seedling growing along the skid trail

Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails; ii) to measure the effects of soil compaction on of maple seedlings growth. Two levels of trail gradient ( < 20% and > 20 %), four levels of traffic frequency (3, 8, 15, and 30 passes) and four distance buffer strip zones (0.5 m intervals from 0 to 2 m in distance) on both sides of skid trail edges were analyzed. Each treatment included three replicate plots. In order to investigate the effect of compaction on seedlings emergence and growth, maple seeds were sown after logging. The results highlighted significant changes in physical and chemical properties of soil for each traffic frequency in the closest buffer strip (from 0 to 0.5 m from the skid trail edges). The largest changes in soil properties were identified at 0.5 m distance zones for a slope gradient > 20% after 3, 8, 15, and 30 skidding cycles. The highest changes were recorded on slope category > 20%. The higher the soil compaction the lower the germination rate, root length, and stem height of seedlings

The effects of thermal-spatial behaviours of land covers on urban heat islands in semi-arid climates

In recent decades, unsustainable urban development stemming from uncontrolled changes in land cover and the accumulation of population and activities have given rise to adverse environmental consequences, such as the formation of urban heat islands (UHIs) and changes in urban microclimates. The formation and intensity of UHIs can be influenced not only by the type of land cover, but also by other factors, such as the spatial patterns of thermal clusters (e.g., dimensions, contiguity, and integration). By emphasising the differences between semi-arid and cold-and-humid climates in terms of the thermal−spatial behaviours of various types of land cover in these climates, this paper aims to assess the behavioural patterns of thermal clusters in Tehran, Iran. To this end, the relationship between the land surface temperature (LST) and the types of land cover is first demonstrated using combined multispectral satellite images taken by Operational Land Imager (OLI), Thermal Infrared Sensor (TIRS) of the Landsat8 and MODIS, and Sentinel satellites to determine LST and land cover. The effects of different behavioural patterns of thermal clusters on the formation of daytime urban heat islands are then analysed through spatial cross-correlation analysis. Lastly, the thermal behaviours of each cluster are separately examined to reveal how their spatial patterns, such as contiguity, affect the intensity and formation of UHI, with the assumption that each point in a contiguous surface may exhibit different thermal behaviours, depending on its distance from the edge or centre. The results of this study show that the daytime UHIs do not occur in the central parts of Tehran, and instead they are created in the surrounding layer, which mostly consists of barren cover. This finding contrasts with previous research conducted regarding cities located in cold-and-humid climates. Our research also finds that the more compact the hot and cool clusters are, the more contiguous they become, which leads to an increase in UHIs. The results suggest that for every 100 pix/km2 increase, the cluster temperature increases by approximately 0.7−1 °C. Additionally, placing cool clusters near or in combination with hot clusters interrupts the effect of the hot clusters, leading to a significant temperature reduction. The paper concludes with recommendations for potential sustainable and context-based solutions to UHI problems in semi-arid climates that relate to the determination of the optimal contiguity distance and land use integration patterns for thermal clusters

Effect of logging wounds on diameter growth of beech (Fagus orientalis Lipsky) trees following selection cutting in Caspian forests of Iran

Background Logging damage to residual trees during selection cutting may lead to serious economic losses in terms of both timber quality and diameter growth reduction. In this study, we investigated the effect of logging operations on residual tree damage and the consequence of injuries on diameter growth in an uneven-aged mixed forest dominated by beech (Fagus orientalis Lipsky)

Comparison of advanced oxidation methods of Fenton, UV/Fenton, and O-3/Fenton in treatment of municipal wastewater

The present study aimed to evaluate the efficiency of advanced oxidation methods: Fenton, UV/Fenton, and O-3/Fenton in the treatment of municipal wastewater. The effect of H2O2:Fe2+ ratio, pH, and reaction time on chemical and biological parameters: chemical oxygen demand (COD), biological oxygen demand (BOD5), total coliform (TC), and Fecal coliform (FC) were evaluated in different advanced oxidation processes (AOPs) methods (Fenton, UV/Fenton, and O-3/Fenton). All parameters were measured according to the standards methods. The results obtained from the present study showed that the highest removal of pollutants was achieved in H2O2:Fe2+ mole ratio of 0.7:1. Furthermore, the removal of COD, BOD5 were increased when pH increased from 4 to 7. Moreover, reaction time influenced COD, BOD5, TC, and FC until equilibrium time, however, its influence was not significant after equilibrium value. A comparative study on different AOP systems showed the order of highest to lowest removal efficiency of all parameters is as follows: O-3/H2O2/Fe2+ > UV/H2O2 /Fe2+ > H2O2/Fe2+. It can be concluded that Fenton and its modified methods have the promising potential for advanced municipal wastewater treatment

Spatial variability of heavy metal concentrations in vineyard soils on Malayer Plains (Iran)

Accumulation of trace elements in arable soils is an important global hazard worldwide. Human activities, such as agriculture, are a continuous source of risk for heavy metal pollution that seriously disturbs the soil environment. In the present study, topsoil (0–20 cm) samples from vineyard soils in Malayer (Iran) were collected and analyzed for heavy metals, including Cu, Pb, and Zn by HR-CS FAAS. Compared with their levels in the earth's crust, these metals exhibited low concentrations. Variations in these metals were studied and geostatistics techniques were applied to generate spatial distribution maps. Empirical semivariograms can be simulated for the three heavy metals by spherical and linear models. The results of the statistical analyses (significant correlations among these metals) and their similar spatial distribution patterns indicate that Cu, Pb, and Zn probably derive from the same origin as their soil parent materials because of low levels of metals in vineyard soils. However, the high concentrations found in eastern-southern regions were probably created by anthropogenic influences, particularly application of manure and fertilizer. © 2016 Taylor & Francis

An Intervention to Increase Detection of Developmental Delays in WIC Programs

Background: Low-income children are at risk for under-detection of developmental disabilities DD. WIC clinics see low-income children regularly in early childhood and could be an important source of referrals to developmental services. Objectives: To increase the number of referrals to EI/ECSE from non-primary care settings such as WIC. Methods: This was a site-randomized trial of an intervention to train WIC staff in early identification of DD’s, using CDC’s LTSAE developmental monitoring materials. 7 county WIC agencies in Oregon enrolled; 4 intervention agencies and 3 control agencies. The intervention consisted of an on-site, half-day training regarding signs of developmental delays, use of LTSAE materials, and referral to EI/ECSE. WIC staff were encouraged to identify and refer at-risk children to EI/ECSE. Control sites received no training and continued their usual processes. Primary study outcome was number of children referred from WIC to EI/ECSE in control vs. experimental counties as well as % of referrals evaluated based on data obtained Oregon’s EI/ECSE program. Results: Data for 46 children referred to EI/ECSE were obtained. Overall, 3 of 4 intervention sites increased their referrals to EI, and 0 of 3 control sites increased referrals. Total referrals in the intervention arm increased from 5 to 33 in the intervention arm, but decreased from 6 to 2 in the control arm. Conclusion: This brief intervention with WIC staff led to short-term increases in EI referrals and evaluations

Systematic Evaluation and Meta-Analysis of Risk, Toxicity Potential, and Carcinogenic and Non-Carcinogenic Risks of Potentially Toxic Elements in Arak City

The industrial areas are located near residential centers in the city of Arak and potentially toxic elements (PTEs) pollution is a serious threat to human health and living organisms in this area. Meanwhile, soil contamination by PTEs is one of the challenges in this region and various studies have been conducted in this area. Meta-analysis studies provide a comprehensive evaluation of the results of a subject. In the present study, soil contamination data for PTEs in the 11 years (2009 to 2020) were studied through the studies conducted in Arak. In this study, the risk, potential toxicity, and carcinogenic and non-carcinogenic risks of PETs were assessed using indices and mathematical relationships. Based on the results of pollution indices, the soil of Arak city in terms of PETs including Zn, Cd, Cr, Ni, As, Pb, Cu, and Hg were categorized into the polluted and highly polluted classes. The soil of the region in terms of PETs has significant ecological risk and acute toxicity. Cadmium, arsenic, and mercury showed the ecological risk of 49.3%, 23.2%, and 18.3% respectively, and nickel, chromium, and arsenic were responsible for 34.7%, 23.03%, and 22.07% of the toxicity potential of PETs in the soil. Arsenic, nickel, and chromium have the highest carcinogenic risk for children in both the ingestion and inhalation pathways, and chromium, arsenic, and nickel have the highest carcinogenic risk from the inhalation pathway for adults. According to the results, the most considerable PETs in the study area including As, Cd, and Pb, and the most important source of their emission in Arak are anthropogenic resources and industries

Effects on soil physicochemical properties and seedling growth in mixed high forests caused by cable skidder traffic

The use of wheel skidders for timber extraction from tree stump to roadside landing has become more and more widespread. Although the use of wheel skidders has the advantages of high production and reduced extraction costs, it also damages the soil and impedes forest regeneration. The main purpose of this study was to investigate the effect of machine traffic using the Timberjack 450C (two, six and 15 passes) on two slope classes (SC) of skid trails. A low slope is considered to be 20%. The effects on soil physicochemical properties and seedling growth (alder, Alnus subcordata C.A. Mey. and maple, Acer velutinum Boiss.) in natural mixed beech stands in the Hyrcanian forests in Northern Iran were observed and studied. The results showed that the different factors of traffic intensity (TI) and SC had a significant impact on soil physicochemical properties and subsequent seedling growth. After two machine passes in a low TI on both low and high slopes, soil bulk density (BD) increased by 49.3% and 59.2% and penetration resistance increased by 30.5% and 38.5%, while total porosity decreased by 19.5% and 23.5%. The forest floor decreased by 30.9% and 42%, organic carbon decreased by 25.6% and 39.4%, nitrogen decreased by 18.5% and 26.3%, phosphorus decreased by 14.1% and 23%, and potassium decreased by 10.7% and 24.2%, respectively as compared with the control area. Our results indicated additional BD increments after two, six and 15 machine passes of 49.3%, 17.9% and 8.3% in the low slope, respectively, and 59.2%, 16.5% and 7.1% in the high slope, respectively. The mean of the germination rate (GR) of alder and maple seedlings in the control area was 58.3% and 46.1%, respectively, while after two, six and 15 passes, the GR of alder seedlings reduced to 50%, 46.4% and 37.5%, respectively, while that of maple seedlings reduced to 36.1%, 28.6% and 25.6%, respectively. Additionally, after two machine passes, stem length, main root length, and total dry biomass decreased by 28.7%, 34.9% and 34% in alder seedlings, respectively, and 27.9%, 27.6% and 33.3% in maple seedlings, respectively. Comparison of the response of the two seedling species to soil compaction showed that although alder had a higher GR than maple, the root growth of maple was higher than that of alder