فصلنامه پژوهشهای علوم و فناوری چوب و جنگل
سال سی‌ام شماره 2 (تابستان 1402)

Studying the structure of the landscape based on the principles of ecology and the spatial indicators of the landscape as its components is considered a suitable tool for mapping and quantifying the spatial characteristics of each land use. Ecological functions, the structure of the landscape, and landscape patterns have undergone unwelcome changes due to the increasing expansion of human activities. Therefore, to monitor and control these changes, quantifying and studying the landscape is important. This study aims to quantify the landscape pattern of regions with different development levels using the line intersect sampling (LIS) method to estimate the metrics of the total length of the forest edge, and the point sampling method was conducted to estimate the metric of contagion. In this regard, the preserved region of Sefidkuh and the manipulated region of Qaleh Gol in Lorestan province were considered.

For this purpose, we selected two 200-hectare areas from the two mentioned regions on Google Earth images and in a GIS environment. To perform the line intersect method, 16 transects with lengths of 100 and 200 m were fitted on the study area using systematically randomized directions. For the paired point sampling method, paired points with 100 and 200 m were systematically and randomly implemented on the selected images, and then metrics were calculated. The outcomes show that in both measured transects, the total length of the forest edge in the Qaleh Gol region is greater than in the Sefidkuh region, and the numerical value of the contagion metric in the Qaleh Gol region is less than in Sefidkuh. Also, the t-student method was applied to compare the regions with different line intersect lengths and paired point lengths. Then, spatial indices were calculated. The paired t-test was also used to compare the different distances in the two regions.

The findings show that there is more disturbance and fragmentation in Qaleh Gol. Moreover, the results indicate that the sampling methods used in this study are a suitable alternative for more detailed vegetation cover maps. The landscape patterns can be quantified by spending less cost and time and with higher accuracy. The obtained results can be used in planning and management at different levels (local, regional, and national), especially in areas with a high rate of change. Also, in this study, it was found that sampling methods are a suitable alternative for vegetation maps with many details. The results of the total length of the forest edge are also consistent with the results of the contagion estimation, and the Qaleh Gol area, which has less contagion, has a longer total length of the forest edge, indicating more destruction and fragmentation of this area compared to the less disturbed Sefidkuh area. Among the reasons for the disturbances in the Qaleh Gol area, we canmention the presence of artificial and man-made disturbances such as numerous villages, agricultural activities, horticulture, livestock grazing, and other rural activities. These have caused the thinning of the forest cover in the area.

Linear intercept sampling (LIS) can be used to estimate the total edge length of forests, while paired-point sampling can be used to estimate the spatial coverage index. These methods can be effective alternatives to detailed vegetation cover maps for downsizing the pattern of land cover in different regions with varying degrees of development. They can also provide a more accurate comparison of land cover patterns with lower costs and in less time.

Ganoderic acid (GA) is a type of triterpenoids produced by various species of Ganoderma. This secondary metabolite has attracted much attention in recent years due to its extraordinary medicinal functions and although Ganoderma Lucidium is famous for having this compound, other species are also considered as alternatives. One of the most important species of Ganoderma is Ganoderma adspersum, which is found as a parasite or saprophyte on living trees or sometimes on tree stumps, and its basidiocarp is very similar to G. applanatum and is often confused. Various medicinal properties such as reducing blood pressure and blood sugar, strengthening the immune system, antiviral, antibacterial and anti-inflammatory properties have been mentioned for this species, and it is one of the main sources of gonodriic acid production. In the present research, while molecular identification of the fungus and ensuring the species, ultrasound waves were used as an elicitor with the aim of increasing total ganoderic acid in in vitro conditions, and the results were examined in both intracellular and extracellular conditions. Mushrooms were sampled in three sizes, small, medium and large, and after purification, they were morphologically and molecularly identified. The samples were cultured in PDA medium and after 14 days in suspension culture medium (PDB), exposed to ultrasound stimulation with variable number (1 to 3 times of sound), time (60, 180 and 300 seconds) and sound temperature ( 30, 40 and 50 °C). Then, extracts were extracted from mycelium and mushroom culture medium in the suspension culture, and intracellular and extracellular gonadoric acid was measured. In order to do the work, RSM response surface method and Benken's box design were used and 17 experiments were designed by Design expert 7 software, and the optimal value of the variables for the maximum production of ganoderic acid was determined with the help of the software. According to morphological and molecular identification, the selected species of Ganoderma is called adspersum. The presence of ganoderic acid in this mushroom was proved. It was found that among the three sizes of mushrooms selected, the larger size (21 x 16 cm) had more ganoderic acid than the other two sizes, and this size was used for sampling and elicitor induction. The highest amount of total ganoderic acid was related to sonication twice for 282 seconds and temperature of 30 degrees Celsius (79.21 mg/g), which increased the amount of total ganoderic acid by 1.6 times compared to the control, while this amount It was 25.48 mg/g in natural mushroom. Cultivation in an invitro environment instead of harvesting from the forest can be used as a sustainable method for extracting plant secondary metabolites. Ganoderic acid is one of the most important anti-inflammatory and antiviral metabolites found in Ganoderma mushroom species. Considering the need for extensive harvesting from the forest and the impossibility of continuous access to the forest, it is necessary to replace the new methods of growing mushrooms in laboratory conditions instead of collecting them from the forest. In the same direction and with the aim of increasing the amount of ganodriic acid, the present research was conducted for the first time on Ganoderma adspersum. This fungus is reported for the first time on Carpinus betulus. Considering the increase of more than 1.5 times of total ganoderic acid after ultrasound treatment compared to the natural mushroom sample, it is suggested to carry out additional research for more detailed identification and type of ganoderic acid.

The formation of soil humus is shaped by both biological and non-biological elements. Biological factors include vegetation type and soil organisms, while non-biological factors encompass climate, topography, and bedrock. Therefore, soil humus form serves as a crucial indicator in forest ecosystems. Previous studies have established a clear correlation between changes in humus form and variations in elevation, yet the connection between humus form and topographical morphology remains uncertain. Hence, this research seeks to elucidate the relation between local-scale changes in humus forms and topographic morphometric indices.. Variables were derived from 510 humus profiles, categorizing the main and secondary humus forms based on the European classification method for terrestrial humus forms, which is specifically designed for temperate mountain forests. The data was collected along an altitude gradient spanning from 200 to 1000 meters within a 1700-hectare area in district one of ShastKalate forest. Primary and secondary topographic attributes were extracted from a Digital Terrain Model (DTM) with a spatial resolution of 10 meters. Discriminant and regression analysis were employed to establish the relationships between variables. The results indicated that dividing the region into two altitude ranges had a significant impact on the accuracy of humus form classification. In the low altitude range (below 599 meters), the overall accuracy coefficient for the main humus form increased by 55%, and for the secondary humus form by 83%. In the middle altitude range (above 600 meters), the overall accuracy coefficient increased by 14% for the main humus form and by 58% for the secondary humus form. Additionally, the Kappa coefficient increased by 112% and 49% for the main humus form in the low and middle-altitude regions, respectively. Regarding humus form abundance, the MULL form was more prevalent in the low altitude zone, while the MODER and AMPHI forms were more abundant in the middle zone. In terms of secondary humus forms, Eumoll was most abundant in the low altitude zone, while Eumoder dominated the middle zone. Furthermore, the frequencies of Eumacroamphi, Eumesoamphi, and Leptoamphi forms were higher in the middle zone compared to the low altitude zone. Contrary to previous research findings, it was observed that altitude had a negative relationship with changes in primary and secondary humus forms in the middle altitude range, while it had a positive relationship in the low range. Similarly, the slope had an opposite effect on humus form changes. Profile curvature and plane curvature exhibited a positive relationship with primary and secondary humus forms in both the low and middle altitude ranges. This implies that an increase in domain concavity along the slope direction and convexity perpendicular to the slope leads to the presence of all humus differential horizons and the formation of a large biological soil structure in the semi-organic Ah horizon. This, in turn, explains the presence of Eumull and Leptoamphi forms. Moreover, the topographic wetness index displayed a positive relationship with changes in both main and secondary humus forms in the low and middle altitude zones. This suggests that as soil moisture increases, facilitated by higher organic matter content in the soil surface horizons, the main humus form tends to shift towards MODER.

Wood, as a renewable and environmentally friendly material, possesses unique mechanical, physical, and aesthetic properties that make it widely used in the construction, furniture, and decorative industries. However, wood is susceptible to degradation by various factors such as biological agents, weathering, and fire. Extensive efforts have been made to enhance the durability of wood, including the use of paints for protection against weathering and moisture. However, both wood and polymer-based paints are flammable. To address this issue, flame retardant materials have been incorporated into paint formulations to reduce flammability. This study aims to investigate the effects of flame retardants on the fire resistance and color changes of acrylic coatings applied to pine wood. In this research, the impact of flame retardant materials (zinc borate, di ammonium phosphate, nanosilica, and nanoclay) at concentrations of 10% and 20%, as well as their binary combinations (20%), in the structure of acrylic paint was examined for their fire resistance on colored pine wood. Subsequently, the tensile strength of the paint film, color changes of the wood samples, and their fire resistance were analyzed. The results of this investigation indicate that zinc borate and di ammonium phosphate did not have a discernible effect on the tensile strength of the paint film. However, the incorporation of nanoclay significantly increased the film's tensile strength, while the addition of nanosilica led to a notable decrease in this property. Among the tested samples, those containing zinc borate and di ammonium phosphate exhibited the least significant color changes. The introduction of flame retardant materials into the paint formulation resulted in improved fire resistance, with ammonium phosphate and nanoclay exhibiting superior performance in this regard. Importantly, there were no substantial differences observed between the 10% and 20% concentrations of the flame retardant materials across many of the conducted tests. Notably, the combination treatments of di ammonium phosphate-zinc borate and di ammonium phosphate-nanoclay demonstrated more effective outcomes concerning color changes and fire resistance. The findings of this study reveal that di ammonium phosphate and zinc borate had the least detrimental effects on the tensile strength of the paint film and the color changes observed in both the wood samples and the paint film. Furthermore, these two flame retardant materials exhibited superior performance in enhancing fire resistance. Therefore, it is strongly recommended to incorporate di ammonium phosphate and zinc borate as flame retardants in acrylic paint formulations specifically intended for use on wood surfaces

Urea Formaldehyde resin is an important rein in wooden panel industries. Compared with other amino resins, this resin is cheap and colorless when it is polymerized. It is used easily since its solvent is water. But it has some disadvantageous such as its low resistance to moisture and its emission during production and service which is harmful for human health. Researchers are conducting massive investigations to substitute formaldehyde in urea formaldehyde resin with other non harmful materials. Furfural is an aldehyde chemical material which react with urea as formaldehyde do. Furfural can be obtained from crop products such as wheat straw, corn stalk and sugar cane. In this study substitution of furfural instead of formaldehyde for making urea furfural resin and improvement of resulted resin using nano clay were investigated. Furfural and urea were mixed with molar ratio of 1 to 1, 1 to 2.2 and 1 to 3.5. Lap -sheer strength test was conducted to evaluate bond strength. Beech strands were dried before gluing. Ammonium chloride was used as hardener. Strand ends were glued using urea furfural resin and assembled. After resin curing in oven, assembled were tensile loaded and tensile strength was measured. 10 samples from each urea furfural resin were prepared for tensile test and tensile sheer strength were measured. results showed that urea furfural with molar ratio of 1 to 2.2 is the best among others. This resin was selected for next step of resin preparation. Nano-clay with amount of 0.5 %, 1 % and 2 % [oven dry wight of resin] was added to urea furfural resin with molar ratio of 1 to 2.2 and resin properties such as density, solid content, viscosity, gel time and bond shear strength were measured. Spectroscopy FTIR, Imaging FESEM and XRD for study reaction of nano-clay and its distribution in the resin were conducted. Results showed that urea furfural resin with molar ratio of 1 to 2.2 with the highest bond sheer strength is the best resin among others. Nano clay at three levels of 0.5%, 1% and 2 % was added to the best resin of urea furfural and caused improvement in resin properties. So that solid content of resin increased from solid content of control (resin without nano clay ) from 56 % to 56.5 %, 56.65%,and 56.8% respectively for adding 0.5%, 1% and 2% nano clay. Density of resin increased from 1.1 gr/cm3 for control to 1.135, 1.14, and 1.145 gr/cm3 for adding 0.5%, 1% and 2% nano clay. Viscosity from 95 second for control to 135,140,143 seconds respectively for adding 0.5%,1 % and 2%nanoclay. Bond shear strength from 1.7 MPa for control to 2.7,0.6 and 0.8 MPa respectively fot 5%,1% and 2% nano clay. Gel time reduced from 180 seconds for control to 160, 145,140 seconds respectively for 0.5% ,1% and 2% nano clay. Findings of this study showed that free formaldehyde urea furfural resin with urea to furfural molar ratio of 1 to 2.2 has the highest bond sheer strength (1.62 MPa) and adding 0.5 percent Nano clay to this resin caused an improvement in its bond sheer strength, density, solid content, viscosity, and gel time. Improvement by adding nano clay up to 5.0% was noticeable but improvement by adding higher levels of nano clay was low. Regarding above results it can be concluded that produced urea furfural with urea to furfural molar ratio of 1 to 2.2 and adding o.5 % nano clay is a suitable substitution for urea formaldehyde resin which can be recommended for particleboard and medium density fiberboard industries.

The recycling of different paper and paperboard products can supply the major shortage of cellulosic raw materials needed for the production of pulp and paper, and it can be important from the economic and environmental point of view. Using recycled pulp in papermaking reduces the quality of the final paper. Therefore, the use of enzyme pre-treatment separately or combined sequences as well as pulp bleaching can be effective in improving the quality properties of the final paper obtained from recycled pulp. This research was conducted with the aim of investigating the effect of enzyme pre-treatment with cellulase and laccase sequence on the bleachability of the resulting pulp with hydrogen peroxide, and the quality of the final pulp after bleaching system were investigated.

At first, the mixture of waste newspaper and magazine papers were deinked using enzyme pre-treatment (combined sequence of cellulase and laccase) as well as conventional chemical method. Enzymatic pre-treatment was done as experimental treatments C1L1 (cellulase usage: 0.1% and duration time: 10 minutes; laccase usage: 20u and duration time: 120 minutes), C1L2 (cellulase usage: 0.1% and duration time: 10 minutes; laccase usage: 40u and duration time: 120 minutes), C2L1 (cellulase usage: 0.1% and duration time: 20 minutes; laccase usage: 20u and duration time: 120 minutes) and C2L2 (cellulase usage: 0.1% and duration time: 20 minutes; laccase usage: 40u and duration time: 120 minutes) under specific process conditions. Also, control pulp (without adding chemicals or enzymes) and chemically deinked pulp samples were also prepared and then bleaching of deinked pulp was accomplished using hydrogen peroxide bleaching system including 2% hydrogen peroxide, 2% sodium hydroxide, 2% sodium silicate, 0.2% DTPA chelating agent and 0.1% magnesium sulfate in separate plastic bags under process conditions of 10% consistency, 70°C temperature and 2 hours in a water bath. At the end, the optical and strength characteristics of the bleached pulp were evaluated.

The results of the evaluation of bleached pulp with hydrogen peroxide after deinking with conventional method and also cellulase and laccase enzyme pre-treatment sequences showed that the use of enzyme pre-treatment in deinking improves the overall performance of the hydrogen peroxide bleaching process and resulted in the papers with better optical and strength characteristics after bleaching compared to pulp pre-deinked by conventional chemical method. C2L2 and C2L1 pre-treatments in combined enzymatic treatments after bleaching with hydrogen peroxide led to an improvement in brightness by 11.12% (increase of about 5 units) and 9.5% (increase of about 4 units), respectively. In these pretreatments, the whiteness of the paper increased by 31.92% and 24.54% (an increase of about 9 and 6 units), respectively. Also, the yellowness of the paper decreased by 40.19% and 44.25%, respectively, and the opacity of the paper reduced by 37.74% and 23.97%, respectively. Also, in experimental runs of C2L1 and C2L2, the paper tensile index increased 29.17% and 35.64%, respectively (40.64 Nm/g and 38.7 Nm/g, respectively), breaking length enhanced by 64.42% and 99%, respectively (5.92 km and 4.89 km), and the paper burst index also increased by 70.85% and 92.37% (3.81 mN.m2/g and 4.29 kPa.m2/g), respectively. The tear indices of paper in these runs were determined on average about 6.82 mN.m2/g and 6.62 mN.m2/g, which are a little lower compared to the chemically deinked pulp after bleaching, but in the pretreatment with the combined sequence C2L1, the tear index of paper was almost equivalent to that of chemically deinked pulp.

Nowadays, safe food packaging is very important for consumers; because it is directly related to people health. Environmental issues have become more important in the production of food packaging. Plastic materials made from fossil polymers cause environmental pollution. For this reason, the use of green polymers, a suitable substitute for fossil polymers in the packaging industry is increasing rapidly. As an eco-friendly material, MFC has some properties required for active food packaging, such as low permeability to oxygen and high tensile strength. Chitosan is also a biodegradable material that antioxidant and antibacterial effects have been recently noticed in food packaging. This study was conducted with the aim of investigating the effect of adding chitosan on the properties of MFC film used in food packaging. At first, the bleached pulp from eucalyptus was converted into MFC with a consistency of 3% using a super disc grinder. To prepare starch, 40 g of starch was added to 1000 mL of water and turned into starch gel using heat. Then, starch gel was added to the bleached eucalyptus pulp with a ratio of 40 to 60% and after passing through the super disk grinding, the prepared gel was stored in the refrigerator. One gram of chitosan was stirred in 100 ml of 1.5 M acetic acid for 24 h, and after preparation, it was added to the bleached eucalyptus pulp and passed through the super disk grinding. Glycerol was also added to the gels as a plasticizer agent. After preparing the films with different compounds by casting method, antioxidant, antibacterial, tensile strength, oxygen and water vapor transmission rate (WVTR) tests and morphological examination with field emission scanning electron microscope (FE-SEM) ) and fourier transform infrared spectroscopy (FTIR) was performed. The results of the antioxidant test using DPPH and ABTS methods showed that films containing chitosan have the free radical scavenging activity. Also, films containing chitosan had an inhibition effect against gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus. The tensile strength of pure MFC films was more than other films, and films containing chitosan and starch had lower tensile strength than pure MFC film. The addition of glycerol to the films caused a significant decrease in tensile strength. The oxygen and WVTR in pure MFC film was less than other films. The films containing chitosan, starch and especially glycerol had higher oxygen and WVTR. The results of this study showed that the MFC/chitosan film is a film with active properties and it is possible to prepare eco-friendly active food packaging films using these materials.

Densification is a mechanical modifying method to improve the mechanical properties of cultivated fast growing woods. A prevalent approach to overcome the set recovery obstacle of densified wood is heat treatment which causes decrease of mechanical properties. Heat treatment with plant functionalized oil, due to reaction of functional groups of oil with hydroxyl groups of wood, leads to an improvement of physical and mechanical properties of wood. The objective of the present research was to compensate the loss of mechanical properties through combination of densification and heat treatment in epoxidized soybean oil. In the present study, fast grown poplar wood was impregnated with raw and epoxidized soybean oil and then densified to a compression set of 30 percent. The epoxidized oil impregnated/ densified wood samples were heat treated in an oven at 180 oC for four hours and the mechanical properties of both densified and non-densified samples, impregnated with the raw and epoxidized oil were investigated comparatively. calculation of oil uptake values of raw and epoxidized soybean oil in densified and non-densified samples showed that in non-densified sample, epoxidized oil had nearly twofold uptake compared to the raw one, because of its higher polarity and higher penetrating ability. Densification led to a considerable removal of oil in both level; however epoxidized oil in densified sample had higher uptake compared to the raw one. Results of mechanical properties showed heat treatment in raw and epoxidized oil caused a 97 and 7 percent loss of flexural strength respectively. Heat treatment of densified wood with raw and epoxidized oil cause a 96 and 20 percent decrease in hardness values compared to the non-heat treated ones. Heat treating of densified wood in epoxidized oil medium led to a decrease of flexibility and impact strength as well. Wood impregnation with epoxidized oil, because of its permeation into the cell wall, led to a considerable decrease of flexural strength and hardness; however densification further increased these strengths. Heat treatment of epoxidized impregnated samples after densification led to a lower decrease of flexural strength and hardness, as compared to raw oil impregnated samples, however this effect was not observed for impact strength. Generally, heat treatment in epoxidized soy bean oil could be recommended as an effective method for decreasing the spring back and water absorption of densified wood which led to a lower reduction of mechanical strength as well.