Journal of Wood and Forest Science and Technology
Year:2020 | Volume:27 | Issue:3|Papers Count:7

Background and Objectives Soils are the largest carbon pool in terrestrial ecosystems, which account for the greatest amount of the global total terrestrial carbon stocks. Accurate mapping of Soil Organic Carbon (SOC) spatial distribution is a key assumption for soil resource management and environmental protection. The rapid development of remote sensing and application of satellite images provide an excellent opportunity to monitor large-scale SOC storage. Estimating SOC is one of the research topics that artificial neural networks are applied for this purpose in some studies, although parameter optimization is difficult. In previous studies, genetic algorithms have been used to optimize the artificial neural network initial weights and improve the prediction of the output variables. However, the effectiveness of this method in estimating the SOC by remote sensing has been less studied. In this study, the effect of genetic algorithm on artificial neural network training to predict SOC on Sentinel-2 satellite images in Arasbaran vegetation zone was investigated. Materials and methods For this purpose, soil sampling was performed using stratified sampling method at 46 points at a depth of 0 to 15 cm. SOC was measured by Walky-Black titration method. In order to fit the model between the measured organic carbon in the laboratory, 9 spectral indices and three bands of satellite image, and two methods were used namely, artificial neural network and artificial neural network optimized by genetic algorithm. Cross validation was used to evaluate the models efficiently. Finally, the precision of the obtained models was evaluated with statistical indices of Root Mean Square Error (RMSE), Ratio of Performance to Deviation (RPD), Spearman's correlation coefficient (r), coefficient of determination (R2), and paired sample t-test. Results The results showed that the precision of SOC estimated by artificial neural network optimized by genetic algorithm (RMSE = 1. 07%, RPD = 1. 89%, R2 = 0. 76) was higher than artificial neural network results (RMSE =1. 51%, RPD = 1. 34%, R2 = 0. 58). Also Spearman correlation coefficient for SOC estimated with optimized artificial neural network (r = 0. 87) was higher compared to estimated SOC with artificial neural network (r = 0. 76). Observed SOC was not significantly different from SOC estimated by optimized artificial neural network (p-value=0. 21) while it was different from estimated SOC by artificial neural network (p-value=0. 02). In addition, the results showed that TSAVI index had the highest Spearman correlation coefficient (0. 565), and BI2 index had the lowest Spearman correlation coefficient (0. 196) with soil organic carbon. Conclusion Generally, it was concluded that the use of genetic algorithm in the selection of artificial neural network parameters improved the performance of this modeling method in estimating soil organic carbon on Sentinel-2 satellite images in the study area. Also the performance of Sentinel-2 satellite images in estimating soil organic carbon in the study area was validated.

Background and objective Today, social equality is more important than any issue in urban management and can affect all aspects of citizens' lives. From the perspective of social equality one of the most important goals of urban planning is access and efficiency fair of all citizens to public services. Urban Parks as an important part of urban green spaces can provide citizens with variety of environmental, social and economic products and services. The well-distributed urban parks are integral part of cities that citizen can access to and benefit from them. This project was conducted to studying spatial distribution of urban parks of Khoramabad city using network analysis and buffering, Material and methods the analysis was conducted using the maps of three districts of city and urban parks. The spatial distribution of parks in the three districts was evaluated in terms of serviceability indices including service area ratio, service population ratio, and service floor area ratio. Results The results showed that per capita urban park areas for 3 districts are 1. 76, 1. 37 and 2. 76 m2, respectively. The simple analysis buffering service area of urban parks was 1693/87 hectares which covers about 47/51% of the total city and total service network of urban parks was 845/06 hectares (approximately 23/7% of the city) that about half of servicing area of the buffering method. Conclusion the results of this study showed that city parks in Khorramabad are poorly distributed in relation to population, land use and density of development. This poor distribution must be considered in future plans in urban parks management.

Background and Objectives Changes in vegetation and land use have been unprincipled on the one hand, and the occurrence of tree decay in the last decade, on the other hand, has put additional pressure on the forests of the Zagros, causing significant significant drying of these forests in particular. It is located in Ilam province. Since awareness of the extent and location of deforestation and spatial distribution of areas at risk of destruction and prevention of this growing trend is the concern of planners and managers of the natural resources sector, the need for sustainable management of these valuable resources is easy access to information and data. The day is high. Therefore, the present study aimed to investigate the distribution of oak tree drying zones in physiographic units (slope, slope direction and elevation classes) as well as land use using geographical information system in this province. Materials and Methods In this study, first, using Alos and Srtm elevation models, in the GIS environment, slope information layers were extracted for slope and elevation classes. Then, based on satellite images and field control, the land use layer of the province was prepared. Also, using the GPS device, the position of the dried oak trees was determined and the relevant dotted layer was prepared. Then, by combining the prepared information layers (slope, slope direction, height floors and land use) with the location layer of dried oak areas, the frequency of tree drought zones of oak forests in physiographic and land use units is determined and examined. Took Results According to the results, the drought rate of trees in topographic units (slope, slope direction and elevation classes) extracted from two models is also 12 meters and Srtm is 50 meters. Percentage (30%). 18% is for the northeast slope and 47% is for the 2000-1500 m high floor. Also, according to the Srtm model, the highest frequency of dried oak areas is related to the slope class of 10-20% (30%), 20% is related to the northern slope direction and 47% is related to the altitude of 2000-1500 meters. In terms of land units, most of the dried areas of oak trees are located in mountainous areas, hills, pebbled areas and plateaus, respectively. Conclusion In general, there is no difference between the percentage distribution of oak drying with slope classes in the two models studied. However, there are slight differences in the height of the floor and the direction of the slope in both models. In terms of forest use, the highest frequency of oak drying is in low (36. 5%), medium (33. 9%) and high (4. 4%) classes, respectively.

Background and objectives The goal of this study was the production of thick insulation panel with lingo-cellulosic residuals and biodegradable binder and evaluation of their physical and mechanical properties. Previous studies showed that the application of lingo-cellulosic residuals in the building has a long history in different places of the world. Many research found that useful to use lingo-cellulosic materials such as bagasse, wheat, and rice straw and sunflower stem in the composition of wood-based panels to improve physical performance. Materials and methods The panels were made with 150, 175 and 200 kg. m-3 density and 30 mm thickness with using three types of raw materials include; wheat, rice, and rapeseed straws. The bonding agent was Vinyl-Acetate homopolymer and the production process consisted of cold press and 55 ° C close system dryer. The compression strength perpendicular to surface and modulus of elasticity were evaluated as mechanical characteristics and sound transmitted class, the rate of temperature exchange and heat conductivity tests were done to probe the physical performances. Results The results showed that the material type has a significant effect on the physical properties and mechanical performances of produced panels. The panels made with rapeseed straws represented the higher amount of compression strength (64 kPa) and modulus (930 kPa) compare to two other raw materials while the physical performance of it was lower than that of wheat and rice straws. Overall, the insulation panels made with natural raw materials represented higher STC than Polystyrene panels. The STC of insulation panels made from wheat straw with highest density was measured as 17 dB. The results of the heat conductivity test showed that the heat conductivity coefficient of panels made with wheat and rice straws meet the coefficient of heat insulation materials. An increase in panel density caused an enhancement in all properties especially in wheat straw panels. Conclusion The lingo-cellulosic materials result from agricultural crops like wheat, rice, and rapeseed could be used as suitable raw materials to produce green insulating panels. Among them, the wheat and rice straw due to better performance in sound absorption and heat insulation, are preferred rather than rapeseed. With this kind of panels, it is possible to reduce petroleum derivatives usage in construction and compensate a part of the minus effects of this industry on the environment. Using lower energy during the production and a small amount of greenhouse gas outcome compare to synthetic materials are two specific features of biodegradable composites which caused production and wide application of them especially in industrialized nations.

Background and Objectives Despite the high potential applications of superparamagnetic cellulose fibers and papers, the hydrophilicity of cellulose and its resulting dimensional instability, as well as the significant loss of tensile strength due to the presence of magnetic nanoparticles on the fibers' surface, have limited the use of these functional materials. This study aimed to investigate the possibility of impregnating cellulose-superparamagnetic papers with epoxy resin and improving their physicomechanical behavior by converting them to nanocomposites. Materials and Methods In this research, superparamagnetic cellulose fibers were prepared by synthesizing of magnetite nanoparticles (Fe3O4) on the softwood cellulose fibers. First, suspension of cellulose fibers was prepared in distilled water at a temperature of 65 ° C, followed by the addition of iron chlorides II and III at a ratio of 2: 1. Treated fibers were transferred out of solution and immediately added to 1 M sodium hydroxide solution at 60 ° C after dewatering to complete magnetic nanoparticle synthesis. After washing, the magnetic cellulose fibers were converted to magnetic cellulose paper (MCPap) with a grammage of 60 g/m2. For comparison, non-magnetic paper (CPap) with the same grammage was produced. The papers were impregnated with a two-component epoxy resin and cellulose paper / epoxy resin (EP-CPap) composites and magnetic-cellulose paper/epoxy resin (EP-MCPap) nanocomposites were made. Microscopic observation, X-ray diffraction, magnetometry, ash determination, static tensile testing, water absorption, and thickness swelling were performed on the specimens and the results were assessed. Results The successful in situ synthesis of spherical magnetic nanoparticles on the surface of cellulose fibers was confirmed by FESEM micrographs. The results of the XRD and VSM tests showed a successful synthesis of magnetite nanocrystals with a diameter of about 7 nm and a superparamagnetic behavior. The weight ratio of magnetic nanoparticles in MCPap paper was approximately 14. 5 percent. The results of the static tensile test confirmed the significant improvement in the tensile behavior of EP-CPap and EP-MCPap over the initial papers. Also, the maximum tensile strength of EP-MCPap did not show a significant difference with EP-CPap, while the tensile strain and energy at the break of EP-MCPap were significantly higher and the modulus of elasticity was significantly lower than EP-CPap. In EP-CPap samples, the maximum water absorption and thickness swelling and the speed to reach the peak assessed values were higher than those in EP-MCPap specimens. Conclusion Microscopic analysis of the paper structure of CPap and MCPap indicated enhanced fiber-fiber interface quality in CPap paper; this observation was attributed to the influence of the presence of magnetic nanoparticles on MCPap paper fibers and the disturbance in the development of the interface between adjacent cellulosic fibers. Despite the considerable advantage of the tensile strength of CPap paper over MCPap paper, probably due to the limited availability of epoxy resin on all fiber surfaces in CPap paper, the tensile strength of EP-MCPap and EP-CPap nanocomposite was not significantly different. It appears that despite the negative effect of the presence of magnetic nanoparticles on the mechanical properties of MCPap paper due to the less dense texture of the paper, the epoxy resin's permeability is improved and therefore the epoxy nanocomposites' tensile behavior and water absorption and thickness swelling are improved. The results of this study confirmed that the impregnation of the magnetic papers with epoxy resin significantly improves the physicomechanical behavior and consequently the development of their potential applications.

Background and purpose the importance of litter thickness in the regulation of microclimate and the physical, chemical and biological characteristics of the soil, the regulation of soil input and output exchanges and evolution and continuity of forest stands and the study of its nature in natural endemic hardwood and planted forests and different environmental conditions is an essential issue. In this study, different techniques of interpolation were analyzed and compared to estimate the spatial variability of litter thickness in the Arabdagh area located in Northeast Golestan province. Materials and Methods Litter thickness data were collected in 422 sample plots with an area of 400m2 using a systematic cluster network (400×600m, each cluster includes 5 plots with a distance of 100 meters) in different hardwood, softwood tree stands and shrub&herb lands including Pinus brutia, Cupressus sempervirens var. horizontalis, Pinus pinea, Pinus sylvestries and broad-leaved species such as Zelkova carpinifolia, Carpinus betulus, Acer velutinum, Parrotia persica and mixed broadleave. Then, after an initial analysis of the data in statistical software, their spatial and descriptive database was prepared in GIS environment. In order to produce litter thickness thematic map, the efficiency of different interpolation methods of EBK, OK, RBF, LPT, LDW and Co-kriging were compared. Cross-validation was performed to evaluate the accuracy of different interpolation techniques by the coefficient of determination (R2), mean relative error (MRE), mean error (MBE), mean absolute error (MAE) and root mean square error (RMSE). Results The results of this study presented that the highest thickness of the litter was in the natural broad-leaved stands and the lowest thickness in the Cupressus arizonica type in the region. Also, in the broad-leaved group, the pure type of Zelkova carpinifolia had the most changes (1. 09 cm). While, in the needle-leaved group, the Pinus brutia type showed the most variation in the thickness of the litter. The results of this study showed that the Co-kriging interpolation method with the exponential (0. 783), spherical (0. 789) and Gaussian (0. 791) models using the auxiliary data of Basel area per hectare and with least-squares error and the highest coefficient of determination had high capability Compared to kriging (0. 8 to 0. 817) and deterministic models (0. 875 to 1. 05) in spatial distribution interpolation of litter thickness in Arabdagh region. Conclusion Due to the effect of litter thickness on some stand and habitat factors such as regeneration, soil quality and Permeability and The intensity of some natural disturbances in the area such as wild fire, it is recommended to take an effective step in managing plan and forestry projects by evaluating it. Due to the effect of litter thickness on some factors of habitat and habitat such as regeneration, soil quality and permeability and the severity of some common natural disturbances in the region such as fire and the results of this study, the Co-kriging interpolation method with the exponential and Gaussian models compared to other methods, due to the accuracy of the results can be more effective in determining the litter thickness of forest stands as well as managing similar stands and afforestation plans.

Background and Objectives Comon Ash is a forest species with versatile biological and medicinal activities that extracts of its various organs are used as a model for making new compounds in the treatment of various human diseases. There is a high correlation between the geographical origin of medicinal plants and the active compounds produced in them. Therefore In this study, using this correlation, the most suitable habitat in terms of production of secondary metabolites is introduced Materials and Methods For this research, selected eight habitats from an altitude range of 200 to 1600 meters (Perchink, three parcels of Panj Amreh series, Alandan, Lala, Qarnsara and Ilal) in Tajan and Siahroud watersheds located in Mazandaran province. In each habitat, 3 tree that were similar to each other in terms of quality characteristics were selected (tree diameter and height, leaf freshness and health, canopy density). Leaf samples from the middle part of the branches. The canopy was harvested in four directions in order to eliminate the effect of geographical direction in sampling. The leaf samples were dried in the open air and after grinding and preparing the extract with absolute ethanol, the leaf extracts were prepared for injection by gas chromatography. In order to study the physical and chemical properties of the soil, a soil sample was taken in combination around each tree base from a depth of 0-15 cm. Then physicochemical properties of soil such as bulk density, acidity, organic crane, total nitrogen, available phosphorus, potassium and calcium were measured in the laboratory. One-way analysis of variance was used to investigate the differences between the sampling areas in terms of secondary chemical composition in the leaves. Pearson double correlation was also used to find out how environmental and soil parameters relate to these chemical compounds. Results The results showed that the characteristics of the sampling location had an effect on the values of the identified secondary compounds. All identified compounds (except Vitamin E and Ferruginol) had a positive correlation with altitude factor. The highest levels of Neophytadiene (27. 7%), Squalene (21. 7%), n-Hexadecanoic acid (26. 8%), Octadecatrinoic acid (28. 3%), Phytol (6. 35%) and Benzeneethanol (10. 39%) were observed in ilal. There was no significant relationship between soil physical properties such as moisture content, bulk density and soil texture with chemical compounds in the leaves. Also, in all studied habitats, there was a significant negative relationship between soil nutrients and identified compounds. Also, a number of identified compounds were observed in only one or more habitats and were not common in all habitats studied. Conclusion The results of this study showed with increasing altitude, the amount of metabolites in the leaves increased and most of the soil nutrients had a negative correlation with the identified chemical compounds. In other words, reducing soil nutrients can cause some kind of stress and increase the production of secondary metabolites in the plant.