Land Use,Land Use Change and Forestry Related GHG Emissions in Lebanon: Economic Valuation and Policy Options

Global climate change has been one of the most challengingenvironmental concerns facing policy makers in the past decade.The characterization of the wide range of greenhouse gas (GHG)sources and sinks as well as the behavior of GHGs in theatmosphere remains an on-going activity in many countries.Lebanon, being a signatory to the Framework Convention onClimate Change, is required to submit and regularly update anational inventory of GHG emission sources and removals.Accordingly, an inventory of greenhouse gases from varioussectors was conducted following the guidelines set by theUnited Nations Intergovernmental Panel on Climate Change. Theinventory indicated that the land use, land use change, andforestry sector contributed about 1% to the totalgreenhouse gas emissions instead of acting as a sink. Thisarticle proposes mitigation scenarios to reduce these emissionsand increase carbon sequestration in the Lebanese land use.Limitations in emission estimation, economic valuation, andpolicy options are also addressed.     

DNA vaccine-encoded glycoprotein B of HSV-1 fails to protect chronic morphine-treated mice against HSV-1 challenge

The use of morphine has been demonstrated to increase susceptibility to infections. Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen among immunocompromised individuals. In the present study, due to the importance of HSV vaccination in morphine abusers, the effects of chronic morphine exposure on the host response to a HSV-1 gB DNA-based vaccine have been investigated. The study is addressing an important aspect of vaccine development among the susceptible (immunocompromised) hosts. BALB/c mice were exposed to morphine over 11 days. They were then vaccinated with DNA vaccine or KOS strain as a live vaccine. The findings showed that the morphine-treated animals failed to respond to DNA vaccination evaluated by the anti-HSV gB antibody titer, delayed type hypersensitivity (DTH) and lethal HSV-1 challenge. Under the same conditions, the KOS vaccine showed a reduced Ab titer and DTH response in morphine-treated mice, but could protect mice against the lethal challenge and was safe for vaccination of morphine-treated animals.     

Anaesthetic efficacy of eugenol on Flowerhorn (Amphilophus labiatus × Amphilophus trimaculatus)

Anaesthetic efficacy of eugenol was investigated on Flowerhorn (Amphilophus labiatus × Amphilophus trimaculatus). A total of 104 fish with average weights of 12 ± 2.5, 28 ± 5 and 53 ±5.1 g were subjected to 25–200 mg L^?1 eugenol and behavioural responses as well as induction and recovery times were recorded. Induction and recovery times were significantly affected by eugenol concentration as well as fish weight (P < 0.05). Generally, 49.9–127.3 s after exposure to 50–200 mg L^?1 eugenol, fish reached stage 3 anaesthesia (suitable for general handling). Fish entered stage 4 anaesthesia (suitable for surgery and blood sampling) over 57.3–140.4 s post exposure to such concentrations. Recovery time was 91.7–312 s in all weight classes for all eugenol concentrations. Mortality (23%) was only observed in 12‐g fish when were subjected to 200 mg L^?1 eugenol. This study showed the behavioural response of Flowerhorn to anaesthesia and eugenol efficacy as an anaesthetic in this important ornamental species. The general quadratic equation revealed that concentrations of eugenol and fish size along with their interactive effects have significantly contributed to the model, with concentration recording the highest beta value in all models (β = ?0.809, ?0.818 and ?0.909, P = 0.000). According to the results, minimum eugenol concentration to induce anaesthesia in less than 3 min was 50 mg L^?1.     

Diurnal and seasonal variations in CH4 flux from termite mounds in tropical savannas of the Northern Territory, Australia

Termites are estimated to contribute between <5 and 19% of the global methane (CH₄) emissions. These estimates have large uncertainties because of the limited number of field-based studies and species studied, as well as issues of diurnal and seasonal variations. We measured CH₄ fluxes from four common mound-building termite species (Microcerotermes nervosus, M. serratus, Tumulitermes pastinator and Amitermes darwini) diurnally and seasonally in tropical savannas in the Northern Territory, Australia. Our results showed that there were significant diel and seasonal variations of CH₄ emissions from termite mounds and we observed large species specific differences. On a diurnal basis, CH₄ fluxes were least at the coolest time of the day (∼07.00 h) and greatest at the warmest (∼15.00 h) for all species for both wet and dry seasons. We observed a strong and significant positive correlation between CH₄ flux and mound temperature for all species. A mound excavation experiment demonstrated that the positive temperature effect on CH₄ emissions was not related to termite movement in and out of a mound but probably a direct effect of temperature on methanogenesis in the termite gut. Fluxes in the wet season were 5-26-fold greater than those in the dry season. A multiple stepwise regression model including mound temperature and mound water content described 70-99% of the seasonal variations in CH₄ fluxes for different species. CH₄ fluxes from M. nervosus, which was the most abundant mound-building termite species at our sites, had significantly lower fluxes than the other three species measured. Our data demonstrate that CH₄ flux estimates could result in large under- or over-estimation of CH₄ emissions from termites if the diurnal, seasonal and species specific variations are not accounted for, especially when flux data are extrapolated to landscape scales.     

Entomopathogenic fungi and plant essential oils are not compatible in controlling Tribolium castaneum (Herbst)

Journal of Plant Diseases and Protection - Entomopathogenic fungi (EPF) and essential oils (EOs) can show either positive or negative interactions when used for controlling insect pests. First, the...     

Effect of Ethephon Spraying at Three Developmental Stages of Barley Planted in Arid and Semiarid Mediterranean Locations

To determine the effects of ethephon [(2‐chloroethyl) phosphonic acid] on yield and yield components of rainfed barley in arid (150 mm rainfall) and semiarid (346 mm) regions, the present study was conducted during the growing seasons of 1999–2001. Ethephon was applied at the tillering, stem elongation and flowering stages. Acomparison of the effect of ethephon on rainfed and irrigated barley performed at the semiarid location in the following season confirmed the results. Ethephon decreased grain yield when sprayed at tillering and stem elongation compared with the later flowering stage for both the arid and semiarid locations. All arid‐location barley plants had lower grain yields than the semiarid‐location plants. There was a reduction in spikes m^?2 in the tillering and stem elongation stage sprayings compared to the control for both locations. In the semiarid and arid locations no difference in earliness (50 % heading) was observed between spraying times but ethephon always delayed heading. All arid‐location plants were earlier than semiarid‐location plants. However, when ethephon was used with supplementary irrigation it was found to increase grain yield, spikes m^?2 and earliness.     

Characterization,pathogenicity and host range studies of Paecilomyces formosus associated with dieback of Christ's thorn trees (Paliurus spina-christi Mill.) in Iran

Christ's thorn (Paliurus spina-christi Mill.) tree is an important and valuable forestry species and has significant potential in afforestation and reforestation systems. In recent years, dieback symptoms were observed on Paliurus spina-christi trees in Gilan-e Gharb region of Kermanshah province, west Iran. During 2020 to 2021, Christ's thorn trees that exhibit branch dieback symptoms were sampled for fungal isolations. The pathogenicity tests, biochemical assay of growth, acid production on creatine sucrose agar (CREA) medium and morphological and molecular investigations (ITS and β-tubulin regions) identified Paecilomyces formosus as a dieback causal agent. This is the first report of P. formosus pathogenicity on Paliurus spina-christi trees. Furthermore, disease severity was assayed on 11 tree species under three different temperatures 15, 25 and 35°C. Disease severity caused by all isolates on detached branches was greater at 35°C than at 15 and 25°C. This study presents the host range of this pathogen and showed that these potential hosts are prone to this pathogen under high temperatures, which forest trees experienced in recent decades.     

The feasibility of using an industrial sewage sludge produce in Pakistan as agricultural fertilizer used for cultivation of Sorghum bicolor L

Abstract

In the present study we evaluate the feasibility of using untreated industrial sewage sludge by liming before use as a fertilizer, produced in Pakistan. In a pots experiment, limed industrial sewage sludge (LSW) and non-limed sewage sludge (NLSW), were amended with soil separately and grown sorghum. After maturity, the sorghum grains were analysed for total contents of potentially toxic metals (TPTM), As, Cd, Cr, Cu, Ni, Pb and Zn. The proportion of different mobility fractions of each element in LWS and NLSW, a modified BCR sequential extraction procedure (Community Bureau of Reference) and single extractions with mild extractants (deionized water and CaCl₂) were used. In LSW, the availability of most of the elements under study was reduced, probably due to the increased pH of soil, while this was the reverse in the cases of Cd and Cu, their mobility was slightly increased by lime-treated sludge. The sorghum grains grown in LSW have low level As, Cr, Ni, Pb and Zn as compared to grains grown in NLSW, except Cu and Cd, which, however, never exceeded legal limits. Thus the research showed that liming, by augmenting soil alkalinity, allows a safe agricultural use even of industrial sludge, which is environmentally hazardous for its great content of heavy metals.     

Heavy Metal Contents of Vegetables Grown in Soil, Irrigated with Mixtures of Wastewater and Sewage Sludge in Pakistan, using Ultrasonic-Assisted Pseudo-digestion

The success of risk assessment of metal‐contaminated soils depends on how precisely one can predict the bio‐availability of trace and toxic metals in soil and transfer to the human food chain. A field experiment was carried out from 2004 to 2005 to evaluate the long‐term effect of sewage sludge application in agricultural lands where mostly vegetables are grown. The aim of this study was to predict the uptake of Cd, Cu, Cr, Ni, Pb and Zn by different vegetables grown on agricultural soil irrigated for long period with untreated domestic waste water and sewage sludge (SIDWS) as test samples and for comparative purposes, same vegetables grown on agricultural soil irrigated with fresh canal water (SIFW), collected as control samples. A sample preparation method based on ultrasound‐assisted pseudo‐digestion (UASD) of soil, sewage sludge and vegetable samples in ultrasonic bath was developed. A conventional wet acid digestion method was used for comparison purposes. The EDTA‐extractable metal in SIFW and SIDWS was also studied. The extracts and digests were analysed by flame atomic absorption spectrometer/electrothermal atomic absorption spectrometer (FAAS/ETAAS). Analytical results for six metals and metalloid by UASD in bath and conventional wet digestion methods showed a good agreement, thus indicating the possibility of using low mass and minimum quantity of digesting acid mixture in less time when compared with the conventional digestion method (CDM). The validation of the proposed UASD method was assessed by using certified reference materials BCR 483 and (whole meal flour) BCR 189. Recoveries ranging from 95.5 % to 102.3 % for understudied metals were obtained for different samples (soils and vegetables). The average relative standard deviation of UASD method varied between 2.3 % and 7.9 % for N = 12, depending on the analyte. The vegetables grown in SIDWS showed high level of heavy metals when compared with control samples. This investigation highlights the increased danger of growing vegetables in the agricultural land, continuously irrigated and dressed with waste water and solid sewage sludge.     

Etching of wood surfaces by glow discharge plasma

This research tests the hypothesis that plasma will cause differential etching of wood cell walls because of variation in the susceptibility of aromatic and aliphatic polymers to degradation by plasma. Wood was exposed to glow discharge plasma, and scanning electron microscopy and chromatic confocal profilometry were used to examine etching of cell walls. Plasma etched cell walls and made them thinner, but the middle lamella was more resistant to etching than the secondary wall. Plasma created small voids within the secondary wall, which were separated by thin lamellae connected to the middle lamella and tertiary wall layers. Larger voids were created in cell walls by the etching of bordered and half-bordered pits. Etching of the uppermost layer of cells at wood surfaces occurs first and when large voids are created in the walls of these cells then significant plasma etching of the underlying cells occurs. Etching of wood cell walls can be quantified using confocal profilometry, and using this technique a strong relationship between applied plasma energy and volume of cell wall etched by plasma was observed. It is concluded that all of wood’s polymers can be degraded by plasma even though cell wall layers that are rich in lignin are etched more slowly than other parts of the cell wall.