مجله محیط زیست و توسعه فرابخشی
پیاپی 74 (زمستان 1400)

Cheetah is the only species from the Acinonyx subfamily and genus whose global population trend has been declining. This species is known as a species with a low genetic variation that has resulted from bottlenecks about 10,000 and 12,000 years ago. All populations of the Asiatic cheetah subspecies are extinct in the Middle East and Southwest of Asia and Iran. Asiatic cheetah subspecies listed in the Critically Endangered because of severe decline in the gene diversity level which has resulted from habitat degradation, geographical separation of populations, and increasing inbreeding, there are only a few of the species remained in the wild of Iran. In this review study, the genetic variation reduction at different levels of Allozymes molecular markers, microsatellites, mitochondrial DNA, and Single Nucleotide Polymorphism in the entire cheetah genome was investigated and validated. studies based on restriction fragment length polymorphism, indicate severe genomic reductions in the occurrence of Single Nucleotide Variant, the density of Single Nucleotide Variant, Single Nucleotide Variants protein-coding genes, Major Histocompatibility Complex genes, and mitochondrial DNA Single Nucleotide Variant compared with other species. Significant reductions in overall genetic variation by multiple genomic markers lead to increased cubs’ mortality, severe abnormalities in sperm growth, problems with captive reproduction programs, and increased vulnerability to the spread of infectious diseases. Since conservation genetics plays a key role in the conservation and management of species, the results of this study can be used in genetic conservation, reproduction in captivity, and the management of the remaining populations of Asian cheetahs.

Urban is a unique and inconsistently defined land cover including green and grey infrastructures. Tree covers that can store large stocks of carbon. There are several ways to estimate a tree's CO2 sequestration. In this study, Google Earth images were used for mapping tree covers in the Hamadan urban scale with an area of 7422 hectares. First, a 50-meter buffer was applied on two sides of the main streets. Then, it was classified into three groups called high, medium, and low density based on the percentage of greenery. In each group, the information of 265 trees (the total of 800 trees) were recorded randomly such as allometric data and canopy diameter of trees. An Object-Oriented approach was applied to extract the area and canopies of individual urban trees. The total number of trees and their location were estimated by dividing the total of trees canopy by the average of the individual urban trees canopy. Allometric equations were used to estimate the dry biomass of tree species. Based on the results, the main species in the study area include maple, black locust, sycamore, manna ash, cypress, fir tree, and elm. The average amount of organic carbon stored in individual and street trees with asphalt and cobblestone pavement is estimated to be about 88.29 kg, which differs significantly from those with the surface covered by soil and grass (an average value of 148.79 kg). In total, the amount of organic carbon stored by Hamadan urban trees is estimated to be 1.6 tons per hectare.

The security and safety of metropolises today is the focus of men's government and urban diplomacy in all aspects of urban life. Also, one of the main components of the security threat is the environmental issue, including air pollution. The issue of air pollution and environmental crisis in metropolitan areas, especially the city of Tehran in recent years has become one of the main concerns of those in charge of the authorities that trying to identify aspects of this crisis along with influential factors has become very important. The present article aims to investigate the relationship between air pollution and security with the mediating role of nanotechnology in the metropolis of Tehran. The present research in terms of descriptive-survey implementation method is based on the purpose of applied research and random sampling method. The statistical population of this study, due to their infinity, a statistical sample based on Cochran's formula, 384 people who are activists and experts in the fields of urban management, political geography, nanotechnology, environment, were selected. According to the research results, the implementation of air pollution reduction policies has an effect on increasing security by using nanotechnology and reducing air pollution and security has a significant and positive relationship with the mediating role of nanotechnology. Also, reducing air pollution and increasing security, reducing air pollution and nanotechnology, nanotechnology and increasing security have a significant and positive relationship.

New methods of risk assessment can significantly reduce the severity of risks and consequently the environmental damage and move towards sustainable development. In this study, using the DPSIR model, the threats and environmental values ​​of Poldokhtar wetlands in the ecological, hydrological and social areas were evaluated and based on the threat score, values ​​and relationship between threats and values, the assessment of wetlands vulnerability and strategies Management was provided in response to the driving forces, pressures, situation and effects of risks. The results showed that ecologically, hydrologically and socially, droughts, fires, and wetland drainage resulted in reduced biodiversity, increased water turbidity and reduced water retention and functional reduction of hunting and hunting area of ​​Poldokhtar wetlands. Effortless. The highest impact of ecological threats on wetland birds was 16.1 on average and the least impact on threats on arid plants with average 2 Environmental risks with a mean score of 10.3 would have an impact on water retention during the period of wetland dehydration, and a functional reduction of 8.6 percent wetland hunting and fishing area was the most important social risk impact.

The abundance, distribution, biodiversity and species composition of phytoplankton and the concentration of nutrient were evaluated in Chabahar Bay during 2018-2019. Phytoplankton succession is mostly posh by physical factors, nutrient availability, mixotrophy and phytoplankton’s predators. Water sampling was carried out by Niskin water sampler from 9 stations in 6 time periods (pre-monsoon, 2 times in southwest monsoon, post-monsoon and 2 times in summer monsoon). The physical and chemical factors were also recorded. In this study, 114 phytoplankton genus and species belonging to 4 main taxa were identified, of which the most dominant phytoplankton was Dinophyta with abundance of 94%. A significant difference of the density of phytoplankton among sampling months was observed (non-parametric Kruskal-Wallis analysis, p≤0.05). Clear paradox between phytoplankton abundance and nutrient concentration was detected. The results showed that increasing the concentration of nutrients by the autumn resulted in highest number of phytoplankton in winter. CCA Analysis explained about 84% of variations on the phytoplankton density cause by nutrient concentration and dissolved Oxygen.

To reduce the solubility of nickel, cadmium, lead, zinc and cobalt of filter cake tailings, resulting from zinc processing, a sample of the mentioned tailings was collected from the accumulation site in Zanjan province. Their chemical properties were measured using XRF and XRD analysis. Then, these tailings were mixed with 0-10%, 0-3%, 0-2% and 0-6% of lime, red mud, cement and GGBFS, respectively, as stabilizers. In order to investigate the reduction of solubility of heavy metals, the extraction process of the samples was performed using 0.05 M EDTA solution, and the heavy metal of these extracts were measured by atomic absorption. The results demonstrate that in samples made with a combination of both lime and red mud, the solubility of all heavy metals except lead was reduced by 45 to 50%. A comparison between the XRD spectra of the control sample and that of the stabilized sample shows that the sulfate form of PbSO4 in the control sample has converted to the carbonate form of PbCO3 in the sample containing lime and red mud, which has more solubility. This change was the main factor in increasing the solubility of lead (87%) in these samples. Cement and slag have been the most effective additives in reducing lead solubility in filter cake. According to the XRD spectrum, the form of PbSO4 in the control sample decreased significantly (100%) after being mixed with cement and slag, which was the reason for the maximum reduction of the solubility of extractable lead in the sample.