University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 The impact of cement dust on some chemical properties of Acacia tortilis-Hammada salicornica soil stands near a cement factory (Case Study: Bandar-e- Khamir, Hormozgan) The impact of cement dust on some chemical properties of Acacia tortilis-Hammada salicornica soil stands near a cement factory (Case Study: Bandar-e- Khamir, Hormozgan) 217 228 99807 10.22059/jfwp.2024.380773.1306 FA Mohammad Pichand Department of Reclamation of Arid and Mountainous Regions, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Mohammad Jafari Department of Reclamation of Arid and Mountainous Regions, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Ali Tavili Department of Reclamation of Arid and Mountainous Regions, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Maryam Moslehi Research Division of Natural Resources, Hormozgan Agricultural and Natural Resources Research and Education Center, AREEO, Bandar Abbas, Iran. 0000-0003-2065-5234 Marzieh Rezai Natural Resources Engineering Group, Agriculture and Natural Resources College, University of Hormozgan, Bandarabass, Iran. Journal Article 2024 08 12 The aim of this research was to examine the effects of cement dust emissions on the chemical properties of soil in Acacia tortilis-Hammada salicornica stands located 0 to 2-kilometers away from a cement factory. To this end, during the plant growing season, three 2000-meter transects with 50-meter intervals were established, and soil samples were collected at distances of 0, 500, 1500, and 2000 meters from the cement factory. The samples, taken from a depth of 0-30 cm (in plots measuring 10×10 m²) under the canopy of the tree species Acacia tortilis (Forssk.) Hayne and the rangeland species Hammada salicornica (Moq.) Iljin in Bandar-e-Khamir, Hormozgan province, were transported to the laboratory for chemical analysis and analyzed using two-way ANOVA at the 95% confidence level. The highest electrical conductivity was observed at the zero-distance treatment (6.53 mS/cm). The percentages of organic carbon, total nitrogen, available phosphorus, available sulfur, and cation exchange capacity at the zero distance, with values of 0.37%, 0.02%, 9.63 mg/L, 22.45 mg/L, and 11.85 cmolc/kg, were significantly lower than those at other distances (P<0.05). The sulfur content and cation exchange capacity were 22.94 mg/L and 13.42 cmolc/kg for A. tortilis, and 23.65 mg/L and 11.71 cmolc/kg for H. salicornica (P<0.05). The distance × species interaction showed that organic carbon and nitrogen varied at different distances for each species, such that at greater distances, the species had higher levels of organic carbon and nitrogen compared to locations closer to the cement factory (P<0.05). The aim of this research was to examine the effects of cement dust emissions on the chemical properties of soil in Acacia tortilis-Hammada salicornica stands located 0 to 2-kilometers away from a cement factory. To this end, during the plant growing season, three 2000-meter transects with 50-meter intervals were established, and soil samples were collected at distances of 0, 500, 1500, and 2000 meters from the cement factory. The samples, taken from a depth of 0-30 cm (in plots measuring 10×10 m²) under the canopy of the tree species Acacia tortilis (Forssk.) Hayne and the rangeland species Hammada salicornica (Moq.) Iljin in Bandar-e-Khamir, Hormozgan province, were transported to the laboratory for chemical analysis and analyzed using two-way ANOVA at the 95% confidence level. The highest electrical conductivity was observed at the zero-distance treatment (6.53 mS/cm). The percentages of organic carbon, total nitrogen, available phosphorus, available sulfur, and cation exchange capacity at the zero distance, with values of 0.37%, 0.02%, 9.63 mg/L, 22.45 mg/L, and 11.85 cmolc/kg, were significantly lower than those at other distances (P<0.05). The sulfur content and cation exchange capacity were 22.94 mg/L and 13.42 cmolc/kg for A. tortilis, and 23.65 mg/L and 11.71 cmolc/kg for H. salicornica (P<0.05). The distance × species interaction showed that organic carbon and nitrogen varied at different distances for each species, such that at greater distances, the species had higher levels of organic carbon and nitrogen compared to locations closer to the cement factory (P<0.05).

https://jfwp.ut.ac.ir/article_99807_8a65a2f0e8288ec81615cdd276fe4a57.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Identification of forest conflicts and assessing their effects on the forest resources in Lordegan County Identification of forest conflicts and assessing their effects on the forest resources in Lordegan County 229 248 99808 10.22059/jfwp.2024.382666.1314 FA Fateme Eshaghi Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Mohammad Avatefi Hemmat Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Parviz Fatehi Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Journal Article 2024 09 27 Forest conflicts, arising from disagreements and conflicting interests among various stakeholders over controlling, managing, and using forest resources, pose significant threats to sustainable forestry. Effective conflict management is crucial for achieving forest policy goals and failure to address disputes properly may lead to the reduction of the effectiveness of conservation efforts and deforestation. This research identifies and analyzes open conflicts in the Zagros Forest of Sardasht forest administration in Chaharmahal and Bakhtiari province, Iran, by examining 27 years of natural resource law enforcement data (1996–2023). Quantitative content analysis was applied to analyze the data, identifying five primary types of forest conflicts: illegal logging, unauthorized charcoal making, forest fires, and national land encroachment. These were categorized into two broad types: resource extraction conflicts and rights/management disputes. These conflicts have caused substantial losses, with an average of 0.04 trees and 0.47 saplings lost per hectare annually, and 344 hectares of national land encroached upon. The underlying causes of forest disputes include unclear property rights, resource scarcity, poor forest law enforcement, and limited livelihood opportunities. Additionally, administrative challenges and poor forest governance hinder conflict recording, reporting, and resolution. Recognizing and addressing forest conflicts is essential for the Natural Resources and Watershed Management Organization to conserve forest resources, reduce the financial and time costs associated with litigation, and promote sustainable forest management. Forest conflicts, arising from disagreements and conflicting interests among various stakeholders over controlling, managing, and using forest resources, pose significant threats to sustainable forestry. Effective conflict management is crucial for achieving forest policy goals and failure to address disputes properly may lead to the reduction of the effectiveness of conservation efforts and deforestation. This research identifies and analyzes open conflicts in the Zagros Forest of Sardasht forest administration in Chaharmahal and Bakhtiari province, Iran, by examining 27 years of natural resource law enforcement data (1996–2023). Quantitative content analysis was applied to analyze the data, identifying five primary types of forest conflicts: illegal logging, unauthorized charcoal making, forest fires, and national land encroachment. These were categorized into two broad types: resource extraction conflicts and rights/management disputes. These conflicts have caused substantial losses, with an average of 0.04 trees and 0.47 saplings lost per hectare annually, and 344 hectares of national land encroached upon. The underlying causes of forest disputes include unclear property rights, resource scarcity, poor forest law enforcement, and limited livelihood opportunities. Additionally, administrative challenges and poor forest governance hinder conflict recording, reporting, and resolution. Recognizing and addressing forest conflicts is essential for the Natural Resources and Watershed Management Organization to conserve forest resources, reduce the financial and time costs associated with litigation, and promote sustainable forest management.

https://jfwp.ut.ac.ir/article_99808_74389e719e6113445c0eecd2506ba69f.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Forest type mapping using PRISMA imagery in the Kheyrud forest Forest type mapping using PRISMA imagery in the Kheyrud forest 249 264 99809 10.22059/jfwp.2024.381635.1312 FA Marjan Firoozy Nejad Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Parviz Fatehi Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Ali Asghar Darvishsefat Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran. Vahid Nasiri Department of Forest Resources Management, Faculty of Forestry, University of Agriculture in Krakow, Krakow, Poland. Journal Article 2024 08 28 Mapping forest types is essential for sustainable management, however, field methods are time-consuming and costly. Therefore, Modern remote sensing, especially hyperspectral imagery like PRISMA with 243 spectral bands, is valuable for mapping Hyrcanian mixed forests. However, its accuracy and capabilities must be assessed. In this study, the capability of PRISMA data was assessed using SVM, SAM, and RF classification approaches to create forest type maps for the Gorazbon district of Kheyrud Forest. A ground truth map consisting of 131 field sample plots, each measuring 45 × 45 m, was generated using Kuchler's abundance method based on the 100 trees with the largest diameters. Five forest types were identified: pure beech, mixed-beech, beech-hornbeam, hornbeam-beech, and mixed hornbeam. Geometric correction, smoothing and noise filtering was applied, then, Illumination correction was performed. Anomalies were detected using the RX algorithm. The minimum noise fraction (MNF) transformation and pixel purity index (PPI) were applied to the remaining 103 spectral bands and then used in the classification process. Additionally, indices such as NDVI, ReNDVI, MTCI, NDIred, and RTVI were incorporated into the classification process. The results showed that the SVM and RF algorithms achieved overall accuracies of 53.09% and 43.19%, with kappa coefficients of 0.38 and 0.25, respectively. The best combination of input data was derived from the spectral bands obtained through the MNF transformation. Based on the findings, high noise in PRISMA imagery and the similar spectral behavior of forest types in this region hindered the species discrimination and classification performance. Mapping forest types is essential for sustainable management, however, field methods are time-consuming and costly. Therefore, Modern remote sensing, especially hyperspectral imagery like PRISMA with 243 spectral bands, is valuable for mapping Hyrcanian mixed forests. However, its accuracy and capabilities must be assessed. In this study, the capability of PRISMA data was assessed using SVM, SAM, and RF classification approaches to create forest type maps for the Gorazbon district of Kheyrud Forest. A ground truth map consisting of 131 field sample plots, each measuring 45 × 45 m, was generated using Kuchler's abundance method based on the 100 trees with the largest diameters. Five forest types were identified: pure beech, mixed-beech, beech-hornbeam, hornbeam-beech, and mixed hornbeam. Geometric correction, smoothing and noise filtering was applied, then, Illumination correction was performed. Anomalies were detected using the RX algorithm. The minimum noise fraction (MNF) transformation and pixel purity index (PPI) were applied to the remaining 103 spectral bands and then used in the classification process. Additionally, indices such as NDVI, ReNDVI, MTCI, NDIred, and RTVI were incorporated into the classification process. The results showed that the SVM and RF algorithms achieved overall accuracies of 53.09% and 43.19%, with kappa coefficients of 0.38 and 0.25, respectively. The best combination of input data was derived from the spectral bands obtained through the MNF transformation. Based on the findings, high noise in PRISMA imagery and the similar spectral behavior of forest types in this region hindered the species discrimination and classification performance.

https://jfwp.ut.ac.ir/article_99809_ae5c714145528bd939ea7ceab2e860df.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 The effect of seed origin on germination percent and seedlings growth of small-fruited cherry (Cerasus microcarpa C.A.M) in nursery The effect of seed origin on germination percent and seedlings growth of small-fruited cherry (Cerasus microcarpa C.A.M) in nursery 265 274 99810 10.22059/jfwp.2024.381600.1311 FA Younes Rostamikia Forests and Rangelands Research Department, Ardabil Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ardabil, Iran. 0000-0003-2007-1247 Maryam Mackizadeh Tafti Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran. Somayeh Fekri Qomi Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran. Behnam Hamzeh Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran. 0000-0001-9642-1018 Journal Article 2024 08 28 Testing the origin of seeds from native species and identifying the appropriate provenance for producing high-quality seedlings and maximizing productivity in forest nurseries is essential. This study aimed to investigate the effect of seed origin on the germination percentage and growth traits of small-fruited cherry (Cerasus microcarpa C.A.M.) seedlings in the Khalkhal region of Ardabil province. For this purpose, ripe and healthy fruits of small-fruited cherry were collected from four habitats in Khalkhal. After measuring their quantitative properties, the seeds were planted in plastic pots containing natural habitat soil at the Kandragh Khalkhal nursery. The traits measured included seed germination percentage, survival percentage, height, collar diameter, and root and shoot dry weights of the seedlings. The findings showed that seeds from the Kandragh origin were larger and heavier compared to those from Barandaragh, Menamin, and Soshab populations. Analysis of variance indicated that seed origin significantly affected all investigated traits. The highest seed germination rate (38%), survival rate (93.5%), height (10.57 cm), collar diameter (2.94 mm), root dry weight (1.04 g), and shoot dry weight (1.98 g) were observed in seedlings from the Kandragh origin. Therefore, Kandragh is recommended as the optimal seed origin for producing healthy and robust small-fruited cherry seedlings in forest nurseries. Testing the origin of seeds from native species and identifying the appropriate provenance for producing high-quality seedlings and maximizing productivity in forest nurseries is essential. This study aimed to investigate the effect of seed origin on the germination percentage and growth traits of small-fruited cherry (Cerasus microcarpa C.A.M.) seedlings in the Khalkhal region of Ardabil province. For this purpose, ripe and healthy fruits of small-fruited cherry were collected from four habitats in Khalkhal. After measuring their quantitative properties, the seeds were planted in plastic pots containing natural habitat soil at the Kandragh Khalkhal nursery. The traits measured included seed germination percentage, survival percentage, height, collar diameter, and root and shoot dry weights of the seedlings. The findings showed that seeds from the Kandragh origin were larger and heavier compared to those from Barandaragh, Menamin, and Soshab populations. Analysis of variance indicated that seed origin significantly affected all investigated traits. The highest seed germination rate (38%), survival rate (93.5%), height (10.57 cm), collar diameter (2.94 mm), root dry weight (1.04 g), and shoot dry weight (1.98 g) were observed in seedlings from the Kandragh origin. Therefore, Kandragh is recommended as the optimal seed origin for producing healthy and robust small-fruited cherry seedlings in forest nurseries.

https://jfwp.ut.ac.ir/article_99810_09c53de1cbd3956dd30f9677a86c58ec.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Mechanical and thermal behaviors of acrylate-modified wood flour/polypropylene composite Mechanical and thermal behaviors of acrylate-modified wood flour/polypropylene composite 275 286 99811 10.22059/jfwp.2024.380801.1307 FA Maryam Ghorbani Kookandeh Department of Wood and Cellulosic Products Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. 0000-0001-9991-925X Nadia Talebi Department of Wood and Cellulosic Products Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. Seyed Mojtaba Amininasab Department of Chemistry, University of Kurdistan, Sanandaj, Iran. Foroogh Dastoorian Department of Wood and Cellulosic Products Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. Journal Article 2024 08 20 The compatibility between the polymer matrix and natural fillers is improved by using a coupling agent or modifying the fillers. This study investigates the effect of acrylate modification of natural fillers with glycidyl methacrylate (GMA) and glycidyl methacrylate/methyl methacrylate (GMA/MMA) on the properties of poplar wood flour/polypropylene composites at different weight ratios, with and without maleic anhydride grafted to polypropylene, produced by the injection molding method. Bending and tensile strengths were significantly improved by increasing the proportion of wood flour up to 30%, but these properties decreased at a filler ratio of 40%. In samples with higher filler ratios, the effect of the coupling agent and filler modification on improving properties was more significant. Notch impact resistance decreased with increasing filler ratio, and the coupling agent and filler modification with GMA reduced this resistance compared to the control samples. The decrease was more pronounced for the composite containing the combined modified fillers, as more force was required for crack development. Greater integrity and fewer holes in the structure of products containing wood flour modified with GMA and GMA/MMA significantly improved the thermal stability of the resulting composite compared to the product containing only the coupling agent, which was more evident for the sample containing the combined modified filler, especially at higher filler ratios. The compatibility between the polymer matrix and natural fillers is improved by using a coupling agent or modifying the fillers. This study investigates the effect of acrylate modification of natural fillers with glycidyl methacrylate (GMA) and glycidyl methacrylate/methyl methacrylate (GMA/MMA) on the properties of poplar wood flour/polypropylene composites at different weight ratios, with and without maleic anhydride grafted to polypropylene, produced by the injection molding method. Bending and tensile strengths were significantly improved by increasing the proportion of wood flour up to 30%, but these properties decreased at a filler ratio of 40%. In samples with higher filler ratios, the effect of the coupling agent and filler modification on improving properties was more significant. Notch impact resistance decreased with increasing filler ratio, and the coupling agent and filler modification with GMA reduced this resistance compared to the control samples. The decrease was more pronounced for the composite containing the combined modified fillers, as more force was required for crack development. Greater integrity and fewer holes in the structure of products containing wood flour modified with GMA and GMA/MMA significantly improved the thermal stability of the resulting composite compared to the product containing only the coupling agent, which was more evident for the sample containing the combined modified filler, especially at higher filler ratios.

https://jfwp.ut.ac.ir/article_99811_3b10973d496dddc8968962c829fcebf8.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Investigating the possibility of making a standard chair from scrimber composite obtained from veneer and wooden layer waste Investigating the possibility of making a standard chair from scrimber composite obtained from veneer and wooden layer waste 287 300 99812 10.22059/jfwp.2024.377211.1297 FA Mehdi Arefkhani Department of Wood and Paper Science and Technology, University College of Agriculture and Natural Resources, Faculty of Natural Resources, University of Tehran, Karaj, Iran. Hamid Zarea Hosseinabadi Department of Wood and Paper Science and Technology, University College of Agriculture and Natural Resources, Faculty of Natural Resources, University of Tehran, Karaj, Iran. Maliheh Akhtari Department of Wood Science & Technology, Bojnourd Branch, Islamic Azad University, Bojnourd, Iran. Mostafa Mohammadabadi Department of Sustainable Bioproducts, Mississippi State University, Mississippi State, USA. Journal Article 2024 05 28 In this research, the possibility of producing standard chairs from scrimber composites made from waste poplar and beech veneer, as well as wood layers from plywood factories, was evaluated. In this process, the waste veneer and wood layers were cut longitudinally and converted into thin veneer scrimbers. Panels with a density of 0.75 g/cm³ and a thickness of 12 mm, consisting of five layers with veneer scrimbers arranged perpendicular to each other, were then constructed, and the physical and mechanical properties of this product were evaluated according to the relevant standards. For the composite production, urea-formaldehyde and phenol-formaldehyde adhesives were used at a rate of 12% of the dry wood weight. Based on the results of physical and mechanical evaluations, the panels made with phenol-formaldehyde adhesive were selected to make chairs with curved backs. The chair legs were made from boards with a thickness of 5 centimeters and parallel veneer scrimber arrangements in the thickness of the board. The produced chairs were qualitatively evaluated according to the national Iranian standard. The evaluation results showed that the chairs made with veneer scrimbers from waste veneer and wood layers met the strength requirements according to national standards. Therefore, it can be concluded that engineered products with standard physical and mechanical properties can be produced using veneer scrimbers from veneer and wood layer waste and can be used in the production of standard wooden chairs. In this research, the possibility of producing standard chairs from scrimber composites made from waste poplar and beech veneer, as well as wood layers from plywood factories, was evaluated. In this process, the waste veneer and wood layers were cut longitudinally and converted into thin veneer scrimbers. Panels with a density of 0.75 g/cm³ and a thickness of 12 mm, consisting of five layers with veneer scrimbers arranged perpendicular to each other, were then constructed, and the physical and mechanical properties of this product were evaluated according to the relevant standards. For the composite production, urea-formaldehyde and phenol-formaldehyde adhesives were used at a rate of 12% of the dry wood weight. Based on the results of physical and mechanical evaluations, the panels made with phenol-formaldehyde adhesive were selected to make chairs with curved backs. The chair legs were made from boards with a thickness of 5 centimeters and parallel veneer scrimber arrangements in the thickness of the board. The produced chairs were qualitatively evaluated according to the national Iranian standard. The evaluation results showed that the chairs made with veneer scrimbers from waste veneer and wood layers met the strength requirements according to national standards. Therefore, it can be concluded that engineered products with standard physical and mechanical properties can be produced using veneer scrimbers from veneer and wood layer waste and can be used in the production of standard wooden chairs. https://jfwp.ut.ac.ir/article_99812_495cd7b641f62521502c5a8987bbe1c8.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Structure analysis of juniper (Juniperus excelsa M.B.) stands in the Irano-Touranin vegetation zone (Case study: Parvar protected area, Semnan province) Structure analysis of juniper (Juniperus excelsa M.B.) stands in the Irano-Touranin vegetation zone (Case study: Parvar protected area, Semnan province) 301 312 99813 10.22059/jfwp.2024.381531.1310 FA Parisa Panahi Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Khosro Sagheb Talebi Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Hooman Ravanbakhsh Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Morteza Moridi Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Mehdi Pourhashemi Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Yousef Ajani Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Maryam Hasaninejad Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Maedeh Fadaei Khojasteh Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Journal Article 2024 08 31 The dynamics of spatial structure play a major role in understanding the mechanisms of forest structure and the formation of biodiversity, and largely determine the sustainability of the forest and its productivity. As part of a long-term monitoring project, the present study was conducted to assess the structure of juniper (Juniperus excelsa M.B.) stands in the Parvar protected area of Semnan province in the Irano-Touranian vegetation zone. Two permanent sample plots, each one hectare, were randomly selected, and the quantitative characteristics of woody species were measured and recorded using the full calipering inventory method. The structural characteristics of the stands were calculated based on the nearest neighbor indices. In sample plot one, juniper was the most abundant species, accounting for 49.7% (94 stems), while Rosa canina was the least abundant, with 4.8% (9 stems). Berberis integerrima and Cerasus microcarpa accounted for 39.7% and 5.8% of abundance, respectively. Sample plot two, with 75 stems per hectare, consisted of only two species: juniper (54 stems, 72%) and barberry (21 stems, 28%). The Clarke and Evans index and uniform angle indices indicated a clustered spatial distribution pattern of trees. The species mingling index for the entire stand in sample plots one and two was 0.46 and 0.38, respectively, indicating moderate mixing. The combined structural diversity index value was 0.47 and 0.48 in sample plots one and two, respectively, suggesting high diversity in the investigated stands. This study demonstrated the effectiveness of these indices in estimating the horizontal structure of forest stands, providing valuable information essential for management and decision-making processes. The dynamics of spatial structure play a major role in understanding the mechanisms of forest structure and the formation of biodiversity, and largely determine the sustainability of the forest and its productivity. As part of a long-term monitoring project, the present study was conducted to assess the structure of juniper (Juniperus excelsa M.B.) stands in the Parvar protected area of Semnan province in the Irano-Touranian vegetation zone. Two permanent sample plots, each one hectare, were randomly selected, and the quantitative characteristics of woody species were measured and recorded using the full calipering inventory method. The structural characteristics of the stands were calculated based on the nearest neighbor indices. In sample plot one, juniper was the most abundant species, accounting for 49.7% (94 stems), while Rosa canina was the least abundant, with 4.8% (9 stems). Berberis integerrima and Cerasus microcarpa accounted for 39.7% and 5.8% of abundance, respectively. Sample plot two, with 75 stems per hectare, consisted of only two species: juniper (54 stems, 72%) and barberry (21 stems, 28%). The Clarke and Evans index and uniform angle indices indicated a clustered spatial distribution pattern of trees. The species mingling index for the entire stand in sample plots one and two was 0.46 and 0.38, respectively, indicating moderate mixing. The combined structural diversity index value was 0.47 and 0.48 in sample plots one and two, respectively, suggesting high diversity in the investigated stands. This study demonstrated the effectiveness of these indices in estimating the horizontal structure of forest stands, providing valuable information essential for management and decision-making processes.

https://jfwp.ut.ac.ir/article_99813_e95fdfa23b68d61c2c05cf4545b9b44d.pdf

University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Performance of beech wood modified with dimethylol dihydroxyethylene urea (DMDHEU) against accelerated weathering Performance of beech wood modified with dimethylol dihydroxyethylene urea (DMDHEU) against accelerated weathering 313 326 99814 10.22059/jfwp.2024.381075.1309 FA Zahra Rezaei Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Asghar Tarmian Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Aisona Talaei Department of Wood Science Engineering, Faculty of Materials Engineering and Interdisciplinary Science, Shahid Rajaee Teacher Training University, Tehran, Iran. Journal Article 2024 08 20 The performance of beech wood modified with methylolated dimethylol dihydroxyethylene urea (mDMDHEU), with low formaldehyde emission, against weathering was investigated. Methylolated dimethylol dihydroxyethylene urea, at a concentration of 30%, and MgCl₂ as a catalyst at 5% by weight were used. After impregnation of the wood samples via the vacuum-pressure process, the samples were cured under superheated steam conditions (100°C for 36 hours) and in an oven (120°C for 24 hours). The weathering resistance of the samples was evaluated under accelerated weathering conditions for 750 hours. The results showed that the weight percent gain (%WPG) was higher in the oven curing method due to the higher treatment temperature; however, the superheated steam curing method showed better performance against weathering. The highest water absorption and swelling occurred in the control sample, while the lowest was observed in the oven-cured sample. The results indicated that the higher treatment temperature led to a further decrease in water absorption and an increase in dimensional stability. FTIR spectroscopy after weathering showed a reduction in the peak of aromatic rings in the modified samples, indicating that lignin was not effectively protected against weathering in any of the treatments. Compared to oven curing, curing with superheated steam resulted in greater water repellency of the surface and reduced changes in color and surface morphology caused by weathering. The performance of beech wood modified with methylolated dimethylol dihydroxyethylene urea (mDMDHEU), with low formaldehyde emission, against weathering was investigated. Methylolated dimethylol dihydroxyethylene urea, at a concentration of 30%, and MgCl₂ as a catalyst at 5% by weight were used. After impregnation of the wood samples via the vacuum-pressure process, the samples were cured under superheated steam conditions (100°C for 36 hours) and in an oven (120°C for 24 hours). The weathering resistance of the samples was evaluated under accelerated weathering conditions for 750 hours. The results showed that the weight percent gain (%WPG) was higher in the oven curing method due to the higher treatment temperature; however, the superheated steam curing method showed better performance against weathering. The highest water absorption and swelling occurred in the control sample, while the lowest was observed in the oven-cured sample. The results indicated that the higher treatment temperature led to a further decrease in water absorption and an increase in dimensional stability. FTIR spectroscopy after weathering showed a reduction in the peak of aromatic rings in the modified samples, indicating that lignin was not effectively protected against weathering in any of the treatments. Compared to oven curing, curing with superheated steam resulted in greater water repellency of the surface and reduced changes in color and surface morphology caused by weathering.

https://jfwp.ut.ac.ir/article_99814_4fe87b106825fc7f3510efb7580e47e8.pdf