مجله پژوهش و فناوری محیط زیست
پیاپی 8 (پاییز و زمستان 1399)

Spatial patterns of trees and their interactions specifically reflect mortality, gap creation, resource use, and also determine population dynamics such as seed dispersal, understory development, initial survival and establishment, growth, and competition. In this study, three one-hectare sample plots in the three stages of early development, maturity and decay were selected in an untouched mixed beech forest in order to consider competition of trees from different height stories along developmental stages and all trees with a diameter at breast height (DBH) larger than 7.5 cm by species were measured based on chest diameter, height and determination of cartesian coordinates using distance-azimuth method. Then, these stems data were first divided into three groups (lower, middle and upper stories) depending on their location in the vertical strata. The spatial patterns and spatial associations were analyzed among different tree height classes using univariate and bivariate Ripley’s K-function. Results showed that spatial pattern varied with canopy strata and scales in different development stages. Positively spatial associations of Fagus orientalis at upper and lower stories in initial and optimal staged and also among F. orientalis at upper and middle stories in decay stages influenced by shade-tolerance characteristics, seed dispersal limitation and the role of larger nurse trees as a shelter of small trees. Competition for resources was observed between Fagus orientalis at the middle story and Carpinus betulus at upper story in the all development stages. Recognizing spatial pattern and natural events guided by nature over time are necessary to carry out targeted forestry operations and In proportion to the evolutionary stages of forest stands.

Amir-Kelayeh international wetland is as one of the important wintering habitats for birds. In present study, the density and diversity of bird species (waterbird, wader and terrestrial bird dependent to the wetland) has been studied in Amir-Kelayeh international wetland based on the semi-winter birds census data, over a 10-year statistical period. During this ten-year period, the total number of 334776 birds from 46 different birds species was recorded in this wetland. Among the studied years, the highest number of 72188 birds in 2008 and the lowest number of 1877 birds in 2015 have been counted. In terms of quality and food items, this wetland and it's around paddy fields is a good refuge for the Anatidae and Rallidae family that with 64.86 and 50.06 percent of frequency depending on their diet, have the most abundant among the identified family. The biodiversity indexes showed a relatively high amounts, but with a declining trend, and also the index of species evenness indicated a stable trend during this 10-year period in Amir-Kelayeh Wetland. Considering the decreasing trend of biodiversity indexes in Amir-Kelayeh wetland in recent years, increasing the wetland ecological conservation through the management plans such as habitat structure conservation, and illegal hunting and pollution control is recommended.

Nowadays, the importance of water is known more than before as a life factor and the axis of sustainable development that to protect and manage it, it needs to be controlled using laboratory tests and various water quality indexes. The purpose of this study was to investigate water quality in diversion dams in Guilan province in which the dams have been ranked using Shannon and TOPSIS entropy methods. The dams included Pasikhan, Shakhzar, Polrud and Tarik and the measured indicators included Ec, pH, TDS, Temperature, SO4, HCO3, Cl, Ca, Mg, Na, TSS, DO, BOD5 and COD. Shannon entropy results showed that among the indicators, the highest index weight is related to TSS with the amount of 0.1973 and the lowest one is related to pH with the amount of zero. Topsis tests results showed that based on the weights derived from entropy and water quality indicators, Pasikhan dam is in the first rank, Polrud dam is in the second rank, Shakhzar dam is in the third rank and Tarik dam is in the last rank. So, according to multivariate selection methods, water quality in different dams with similar conditions can be investigated.

Identify land uses and land use changes to investigate and monitor sensitive areas is essential for sustainable land planning and management. The main objective of this study is to investigate the land use changes caused by the construction of Shafarood Dam in the Hyrcanian forests in the north of Iran during a 17-year period using Landsat satellite imagery. To do this, three satellite imagery of the years 2000, 2013 and 2017 were used, and the corrections (geometric and atmospheric) were applied on the images and the map of the land use for each section in the region was prepared using the classification method of the maximum likelihood that the produced map have Kappa coefficient more than 86% and usage accuracy of 0.83. After classification, the comparison method was used to monitor the land use changes. The results revealed that in every three years, the most land cover of Shafarood watershed belongs to the forest class and in the next rank belongs to the rangeland class. As a result, the continuous decline of the forest class accured from 63.05 percent to 57.27 and 57.22 percent in the first section for the years 2013 and 2017 respectively. The continuous increase of the rock class (8.15-9.10-10.45) and bare lands (3.5- 4.47-5.08%) confirms it in the study area. Environmental challenges of constructing the Shafaroud dam is another emphasis on the importance of conducting advanced and specialized studies based on ecological methodologies and also increasing the decision makers awareness of Hyrcanian forests complexity which has formed in a very long-time period.

National parks and wildlife shelter are the most important natural heritages; therefore, knowing of quantitative and qualitative changes in their land use plays an essential role in the quality of these areas' management. various algorithms have been developed to classify satellite imagery in remote sensing, selecting an appropriate classification algorithm is very important in achieving the accurate results. In this research, a more accurate algorithm was determined by comparing the classification accuracy of two artificial neural network and support vector machine algorithms, and it was used to examine the process of the land use changes. The present study was performed in Boujagh National Park, in the Guilan Province, during the years 2000 to 2017, using satellite imagery ETM and OLI of Landsat 7 and 8. The results of the research revealed that the support vector machine algorithm with overall accuracy and Kappa coefficient of 86.42 and 0.83 respectively for the year 2000 and, 90.65 and 0.88 for the year 2017, classified the satellite images more precisely, in comparison with the artificial neural network algorithm with overall accuracy and Kappa coefficient of 83.71 and 0.80 respectively for the year 2000 and overall accuracy and Kappa coefficient of 89.25 and 0.87 for the year 2017. Therefore, the land use maps of the support vector machine algorithm were used to determine the land use changes. The study of land use change by this method concluded that the areas of the waterbody, sea, grassland and agriculture have decreased and marshland, woody and bare lands classes showed an increase during the study period.

To investigate the effects of the whole dill plant powder different levels on performance of some blood parameters and tibial characteristics of broilers, 200 one-day-old male chicks (Ross-308) were used in a completely randomized design with four treatments and five replicates (10 chicks per replicate). Chicks were randomly distributed among the experimental treatments including 0, 0.5, 0.1, and 0.2% levels of whole dill plant powder. In regards to feed intake and weight gain during the entire growing period, the treatments contained 1% and 2% of dill plant powder had the highest and the lowest feed intake, respectively, and treatments containing 0.5% dill powder and control group were in the middle of the first two treatments (P<0.05). In terms of feed conversion ratio, the only significant difference observed between treatments throughout the entire experimental period was a significant increase in the amount of feed conversion ratio in the chicks treated with 2% dill plant powder. Serum alkaline phosphatase concentration showed a significant increase in both assessing periods (21 and 42 days) for the 2% dill plant powder treatment compared to the other experimental treatments (P<0.05). Serum calcium and phosphorus concentrations were not affected by experimental diets. The weight, length, width, and ash percentage of the tibial bone did not show any significant difference between the experimental treatments. The results of this study showed that using 1% of dill plant powder in broiler chicken diets, while improving growth performance, did not have any adverse effect on skeletal growth and development of chickens.

One of the characteristics of municipal wastes is the high percentage of perishable organic matter, which is associated with a significant amount of leachate production. Waste leachate, whether fresh, compost or landfill leachate, has a variety of suspended and soluble organic and inorganic materials, and may also contain a variety of pathogens and heavy metal compounds. Therefore, the leachate can lead to many environmental problems. The purpose of this study is COD removal from landfill leachate using bio-magnetic iron (III) oxide/sawdust nanocomposite. First, Fe3O4/SD magnetic nanocomposite was synthesized by the chemical precipitation method and the structure and morphology of the synthesized nanocomposite were investigated using X-ray Diffraction (XRD) and Field Scanning Electron Microscopy (FE-SEM) technique. Then, the effect of influential variables on the adsorption process including pH, contact time, adsorbent amount, and temperature on the removal of COD were investigated. The results of effective parameters showed that the highest COD removal efficiency was observed at pH 7, the adsorbent amount of 0.4 g, the contact time of 45 minutes, and the temperature of 45°C with a removal efficiency of about 70%. Also, the isotherm studies confirmed that the removal process followed the Freundlich isotherm more closely (R2= 0.9243) and the heterogeneity and multilayers of the adsorption process were confirmed. Finally, the results showed that treatment of the landfill centers leachate's organic load is possible using the adsorption process of Fe3O4/SD magnetic nanocomposite and can be used as an efficient method in leachate treatment of landfill centers and compost plants.

Gorgan Bay in Golestan Province is important biological and fisheries area; while in recent years, it has been contaminated Severely; Therefore, the most important pollutant factors were studied using SWOT model in this study.For this purpose, weaknesses, strengths, threats and opportunities have been identified in the ecosystem and were evaluated by 10 ecology and hydrology scientists. The results included 2.4 for external factors and 1.89 for internal factors. Accordingly, both values are in the range of defensive strategies. Defensive strategies control existing weaknesses and threats to improve ecosystem conditions. The most important pressure factors on the ecosystem are being the main canals of the sea closed to the bay, the entry of various pollutants into the ecosystem and poor physiography of Gorgan Bay. According to the importance of the surface water resources in terms of food production for society, and in order to sustainable development, we should manage them consciously to provide suitable habitat for aquatic species in addition to protecting water resources.

Ecotourism seeks to minimize the impact of tourism on the environment. Green economy as an economic system is based on human welfare and social equality that seeks to significantly reduce environmental risks. The present study surveys one of the specialized potentials of tourism in the country- ecotourism- to apply the principles of this development model. Ecotourism with natural management of a tourist area can create jobs without destructive and exploitative actions in nature, which will be beneficial for the region in the future. Also, ecotourism, as a possible potential can encourage the community to extensively implement green economy, in addition to promoting environmental awareness and providing benefits and financial empowerment of local people. Therefore, the present study, identifies the opportunities and threats of external factors and the strengths and weaknesses of internal factors for the development of ecotourism as a driving force of green economy in the country meanwhile examining the existing national and international background using SWOT analysis. The results indicate the need to take advantage of opportunities such as attracting regional, international cooperation and foreign investment by taking principles advantage of biodiversity and geographical location in the country along with the participation of local communities in decision-making, job creation and earning money. Therefore, in addition to the role that the tourism boom plays in the development of a green economy, it will also performs a significant role in the country's GDP (Gross Domestic Product) and foreign exchange income of the country.

 In designing ecological industrial parks, an attempt is to maximize the self-purification of the system by defined mechanisms in order to reduce the pollution produced by industries first and then, to reuse the by-products of industrial processes. Due to the high vulnerability of the coastal sector, species diversity and rapid sequence in the region, the use of environmental methods in the environment of shahid salimi powerplant (Neka) is inevitable. The purpose of this study is to calculate and model the distribution of SO2, NOx pollutants to be displayed seasonally and annually using ADMS software in the form of GIS layers and to achieve the design criteria of an eco- industrial park in the study area, the mass flow of SO2 and NOx is calculated in gr/sec and also the flue smoke of the powerplant fuel consumption is analyzed in cold and hot seasons of the year separately. The results showed that in Neka power plant, the average concentration of NOx gas per unit of steam is 304 μg/m3 and in combined cycle unit is 77.75 μg/m3 and also the average concentration of SO2 per unit of steam is 267.25 μg/m3 during the year which does not meet any of WHO and European clean air standards.

The aim of this study was to investigate the effect of maintenance performance on HSE indicators in Iran Zamin Printing Industrial Group. Therefore, first the dimensions and maintenance performance and HSE dimensions are identified and then the relationships between the identified variables are presented. The aim of this study was to investigation of the effect of maintenance performance on HSE indexes in Iran Zamin Printing Industrial Group. Therefore, at first the dimentions of maintenance and performance and HSE indexes were identified and then the relationships between the identified variables were presented. A researcher-made questionnaire was used to collect data related to the measurement of the research variables, which included a total of 2 structures, 10 dimensions and 54 questions. To investigation of the validity of the questionnaire, the content validation method and the structural validity method were used. Cronbach's alpha coefficient was used to reliability calculation and the reliability was equal to 0.861, which the reliability of the questionnaire has been evaluated as very desirable. The statistical population of this study includes employees and experts of Iran Zamin Printing Industrial Group. After confirming the validity and reliability of the designed scales based on the calculations performed, the questionnaires were distributed in a sample of 108 people. Structural equation modeling has been used to analyze the collected data and determine the relationships between the variables. Also, the obtained data were analyzed using SPSS and LISREL statistical software. According to the analysis of the research hypotheses: Repair and maintenance performance has a significant effect on the structure and dimensions of safety, health and environment in Iran Zamin Printing Industrial Group.Structural equation modeling has been used to analyze the collected data and determine the relationships between the variables. Also, the obtained data were analyzed using SPSS and laser statistical software. According to the analysis of the research hypotheses, the results of the research are as follows: The performance of maintenance has a significant effect on the structure and dimensions of safety, health and environment in Iran Zamin Printing Industrial Group.

The automobile manufacturing industry has always been the focus of experts attention and those involved in safety and environment due to its extensiveness, huge amount of capital, pervasive risks and large number of people working in this industry and extensive efforts takes place to increase the safety of this industry in the world. The primary purpose of risk assessment is to assess the risk potentials of a project and its potential effects on environmental and human health parameters. This viewpoint can be considered by managers and planners in the processes of design, construction, implementation and maintenance of development plans with the least possible risks and the highest safety. In this research, after conducting library and preliminary studies, we collected information from companies in the utomobile manufacturing industry to analyze the causes of the accidents. Then, by using FTA and FMEA methods, the roots of different types of accidents were traced. The results show that in the initial risk assessment, the highest number of the risk is related to fire risk and the lowest number of the risk is related to dust, glass fiber dust and throwing objects.