Journal of Forest and Wood Products
Year:2017 | Volume:70 | Issue:2 |Papers Count:21

Although the ecological and social benefits of agroforestry systems are well known, the acceptance of these systems amongst farmers is emerging slowly. Introduction of the most profitable agroforestry systems and proving their advantages compared to traditional farming systems, may increase the social acceptance of these integrated trees and crop cultivations. This study aims at evaluating evalute the agroforestry systems financially developed in Chadegan anf Frieden cities of Isfahan province.Aroforestry systems and practices developed in the study area were first identified and recorded. Then, planting, growing and harvesting activities (type and amount) of agroforestry systems were examined over a periode of 10 years through survey method. Average cost and revenue of agroforestry activities and inflation-related data were extracted from the annual reports of Agriculture– Jahad Organization of Isfahan Province and Statistical Center of Iran, respectively. Financail calculations were performed using Land expectation value (LEV) and Equivalent Annual Value (EAV) criteria and nominal discount rate (the sum of the real discount rate of 3 to 5% and the average of inflation rate during the study period). Results showed that alley cropping of alfalfa and fruit trees has the highest financial return amongst the agroforestry systems of the region while windbreak (shelterbelt) and trees for soil conservation were ranked second and third, respectively. Further research is necessary to know how farmers decide amongst agroforestry systems and how to encourage them to apply the optimal one.

Birch (Betula sp) species is too important because of little regeneration in mountain cliff region, medicinal, industrial and ornamental function. Betula litwinowii is one of two tree species Birch in Iran that is endangered and grown in Sangdeh of Sari County. In this study, leaf explants after sterilized by applying different treatments (HgCl2 0.1%, Ethanol 70% and NaClO 25% in different times) in both MS and WPM medium with various concentrations of BAP and 2, 4-D hormones, for calli produce and reproduction of B. litwinowii species in Gorgan University of Agricultural Sciences and Natural Resources In vitro lab were cultured. Result showed that HgCl2 (0.1% for 7 min) was the best method for sterilization of explants. The WPM medium enriched BAP (1 mgl-1) and 2, 4-D (0.1 mgl-1) was found to be the best medium for callgenesis. The concentrations Zeatin (10 mgl-1) and AS (20 mgl-1) hormones Too were suitable for Stimulation organogenesis. Combination of BAP (0.5 mgl-1) and AS (20 mgl-1) hormones was selected the best treatment with 20% organogenesis. Finally, plantlets in WPM medium with (IBA and NAA 1 mgl-1) rooted. Micro propagation of Birch that improved in this research, in biotechnology research with aim of Birch genetics progression are usable.

Increasing soil strength would adversely affect the seedling morphology (size) and growth (biomass) by changing the above- and below-ground patterns. In this research, the effects of soil compaction were explored in a loam to clay-loam textured soil with optimal conditions of water on a continuous scale on growth responses of the Pinus nigra in four intensity treatments of soil compaction (the lowest intensity of compaction, low, moderate, and high intensities of compaction). Results showed that the above- and below-ground metrics of seedling size (i.e., stem length and diameter, leaf length, main root length and diameter, and lateral root length) and biomass (i.e., total, shoot, and total root) were negatively affected by soil compaction. Seedling sizes and growth parameters responded non-linearly by increasing soil strength. Increasing soil strength changed the above- and below-ground biomass allocation patterns (i.e., root mass ratio, root: shoot ratio, specific root length) resulting in unchanged seedling architecture. It is concluded that growth of roots and heights of black pine seedlings are restricted with any increase in soil strength. The increasing soil compaction causes significant differential growth allocation patterns to above- and below-ground portions resulting in architectural changes to the seedlings.

In this study, the site form index which is the most reliable criterion for evaluation of forest site productivity in uneven-aged and mixed stands was used. For this purpose, random-systematic sampling method was used to locate 105 0.1 ha circular sample plots in beech dominated forests in Tarbiat Modares University research forest. The height and diameter ofFagus orientalis Lipsky trees within each sample plot was recorded along with elevation, azimuth and slope of the ground. Also, at the center of plot, soil samples from first layer (0-10 cm) were taken for analyzing several soil variables. Evaluation of forest site productivity by using classification and regression tree algorithm showed that after pruning the full tree, phosphorus, TRASP, clay and bulk density are effective variables, in order of relative importance, on site form and 62% variations in productivity can be explained by these variables. Using generalized linear model and evaluation criteria such as AIC, RMSE, R2 and adjusted R2, the performance of CART model was assessed. The results showed though CART techniques and the generalized linear model justify the same variability in forest productivity but decision tree technique in terms of AIC and BIC criteria is better than the GLM and as well as this technique is easier to interpret.

This research was performed to study the variability of nitrogen and phosphorus nutrients in leaf, root and soil around the root of dieback affected Persian oak trees during two years in spring and summer in Melah-Siah region, Ilam province. Oak trees were divided into four groups with six replicates based on the severity of crown dieback. Sampling of leaves, roots and soil of trees was randomly performed in four directions of tree crown and were transferred to the laboratory for analyzing the nutrients. Results showed that the leaf nitrogen amount of dieback trees in spring and summer of 2013 was more than those of healthy trees. The leaf phosphorus amounts of dieback trees in spring 2013 and spring 2014 were less than those of the healthy trees. The root nitrogen amount of dieback trees in spring and summer 2013 was more and in spring 2014 was less than that of healthy trees. The root phosphorus amount of dieback trees was less than that of healthy trees in all sampling seasons. The results showed that N had declining temporal changes. But temporal change of P was increasing. The concentrations of N and P in leaf were also more than the root. It is concluded that drought has significant effect on the mentioned elements status in oak trees. Resisting to drought conditions and possibly performing the vital activities are the reasons for element status changes in the dieback trees.

In general, forest recreation benefit is among the the free of charge benefits, but it can play an important role in forest resources management. Estimating the recreational value of a forest area can help forest managers to make decisions for choosing the type of correct land use. The aim of this study was to estimate the recreational value of Chaghasabz Park of Ilam city using contingent valuation method. In order to estimate the willingness to pay of the local people, the logit model based on the maximum likelihood was used. The data was obtained from 280 questionaires from visitors of the park. The results showed that the average willingness to pay per person and per household to visit this park were 13969.4 and 41908.2 Rials, respectively. Moreover, the results showed that income, education, age and the proposed amount variables had the most significant impacts on the acceptance of the suggested amounts.

In order to test the hypothesis of connection between the changes in climatic parameters and declining northern Zagros forests in the west of Iran, long-term trends of meteorological parameters and reference evapotranspiration (ET0) on seasonal and annual time scales using three synoptic meteorological stations of Piranshahr, Saghez, and Khoram-Abad were examined. The Penman-Monteith combination equation was applied to calculate the ET0. To examine the long-term trends of meteorological parameters and ET0, the non-parametric tests of Mann-Kendal and Spearman were used and the magnitude of the slope of trends lines was tested using the Sen-slope estimator. Results showed that the increasing trends of air temperature in Piranshahr (1986-2009) were statistically significant (P<0.01). Wind speed exhibited a significant positive trend in Saghez (1970-2009) and Khoram-Abad (1970-2010) by Spearman test (Saghez at 0.05% level, Khoram-Abad at 0.01% level). On seasonal time scale, the trends of climatic parameters and ET0 were similar by Mann-Kendal and Spearman tests and ET0 trends were positive in most stations. This preliminary research indicated that long-term trends of some climatic parameters and ET0 in the northern Zagros region were statistically significant so that the hypothesis of the connection between decline of northern Zagros forests and changes in meteorological parameters was confirmed. Greater number of meteorological stations throughout the Zagros region, however, should be included in future research.

Due to lack of scientific information regarding to health and safety and in spite of the accidents and health problems of forest workers, this study was carried out on forestry workers of Shafaroud forest company in the west forest of Guilan province. Occupational health and safety, job satisfaction and cumulative fatigue symptoms of forest worker and effective factors on them were analysed by questionnaire. For this purpose, 100 workers were randomly selected and their response were gathered by interview method.54 percent of workers were hurt on the job and the majority of them were felling and skidding workers. Although the use of safety devices are necessary to prevent the accidents, 20% of workers did not have the personal protective equipment. The employee job satisfaction in working groups were compared using Friedman test. The results showed that the felling and skidding workers had the highest dissatisfaction index compared with others. The most important reasons for worker dissatisfaction were the low wages and heavy work. Age, work experience, and type of work were the most important factors having a negative impact on job satisfaction. The study result for cumulative fatigue symptoms index showed that the value of feelings of anxiety, depression of psychological aspects, physical disorders and general fatigue from the physical point of view, were more than the standard values.

Soil physicochemical properties are important factors in plant establishment. Therefore, knowing its properties can improve the forest management practice for having more forest production. The objective of the present study is to determine the soil physicochemical properties of Tecomella undulata stands in Bushehr province. For this purpose, two sites including Shahnia (2 ha) and Ali-Abad (10 ha) in Bushehr province were selected.20 and 30 soil samples were systematically taken from two depths (0-5 and 5-25 cm) using 25´25 and 50´100 meter grids in Shahnia and Ali-Abad, respectively. Soil physicochemical properties results revealed that T. undulata prefers sandy and loam- sandy soils with neutral pH. Also, this species can tolerate more than 535 ds/m soil electrical conductivity in the studied sites. Soil phosphorus, bulk density and clay are the most important factors effecting the T. undulata distribution. Results of quantitative parameters showed that diameters at breast height in Shahnia are significantly more than Ali-Abad. While no significant difference was observed among tree heights in the studied sites.

This study aimed to investigate the role of soil mesofauna for quick and low cost detection of well and poorly seed-origin oak regenerated sample plots in Zagros oak forest ecosystem. The main question of this study is why some areas have a suitable number of natural seedlings while some others do not, despite the presence of mature oak trees? In this study, we sampled 30 100-m2 plots with regeneration and 30 100-m2 plots without or with only few seedlings in the same physiographic conditions. Soil samples for mesofauna investigation were randomly collected within each sample plot to a depth of 0-20 cm. Soil mesofauna was extracted with a Berlese-Tullgren funnel apparatus. According to CCA ordination, plots with and without natural regeneration have shown, respectively, clumped and uniform patterns of mature oak trees based on Johnson and Zimmer index. In this regard, plots with a clumped pattern were characterized by higher saturation percentage, total phosphorus, total potassium, clay, organic matter, total nitrogen and cation exchange capacity than uniform to random patterns of oak trees. Seed-origin oak regeneration patterns around mature oak trees in plots with and without natural regeneration were clumped and uniform, respectively. The results showed that the number of soil mesofauna in clumped pattern (with higher regeneration) was higher than those in the uniform pattern (with lower regeneration).

Alnus subcordatais one of the native and the fast growing trees in Hyrcanian forests which its plantation helps to conserve and protect the forest. In this study, for surveying the quantitative and qualitative characteristics of Alnus subcordata with changing the elevation above sea level, four sites were selected in Pahne Kolla forests, Sari, Iran. The systematic random method was used for tree sampling and finally the quantitative and qualitative characteristics of 338 trees were measured. Such characteristics as diameter at breast height, slenderness index (h/d), basal area, trees volume (m3/ha), stem quality, canopy percentage and regeneration in the study area were recorded. The results indicated that average DBH, volume and basal area of trees at elevation 430 (m a.s.l) and average height of trees and slenderness index (h/d) at elevation 600 (m a.s.l) were the highest among other elevations. The comparison of average DBH and height of trees in the sites demonstrated that sites have significant difference whit each other. Therefore, according to the results, altitude is an effective factor in the quantitative and qualitative characteristics of Alnus subcordata.

This research was conducted to study the spatial patterns, inter and intra-specific associations of tree species that may provide valuable insights into processes and mechanisms that maintain species coexistence. Data collection was done using three one-hectare (100 m´100 m) plots from three development stages (initial, optimal and decay) in an intact mixed beech forest. The positions of all trees with diameter at breast height (DBH) larger than 7.5 cm were recorded using azimuth-distance method.The measured trees were then divided into four diameter size classes. Spatial patterns and spatial associations among tree size classes (intra-specific) and among species (interspecific) were analyzed using univariate and bivariate Ripley’s K -function. Results indicated that spatial patterns of trees are aggregated, slightly aggregated and random for initial, optimal and decay stages, respectively. Over time, shade-tolerant nature and intra-specific competition of beech trees from different size classes as well as inter-specific competition between beech- hornbeam and among beech- other species across different development stages indicated the different situations. Structural differences, various ecological nature, various reaction of different species to environmental variables at different life stages, difference in growth and physiological mortality due to mixed studied stands can be considered as effective factors in these difference. Knowledge about spatial pattern and natural events are the prerequisite for the implementation of targeted silvicultural interventions and commensurate with the potential and development stages of forest stands.

Correction of edge effect in Ripley' sK -function is important for obtaining unbiased results in spatial pattern analysis of trees. This research aimed at studying the capability of Ripley's K -function corrected by three major edge effect correction methods for square plots (guard, toroidal and weighted) to identify the spatial patterns of Christ's thorn jujube (Ziziphus spina-christi) in Fars Province. A true and two simulated 200´200 m2 plots with different spatial distributions of trees (aggregated, clustered, and random) were selected to investigate the analytical power of corrected Ripley's K -function. When computed with no correction, the results showed that Ripley's K -function was biased and the bias increased with increasing distance. The theoretical values departed the simulation envelopes in the true (aggregated) and two simulated (random and dispersed) plots of Christ's thorn jujube trees illustrating that edge effect correction was necessary. The guard method showed unbiased results for the random pattern (root mean squared error less than 20) while the root mean squared error of this method was high for the non-random patterns (more than 120 in clustered and about 80 in aggregated patterns). The toroidal and weighted methods were efficient in pattern analysis of dispersed and aggregated distributions of Christ's thorn jujube, respectively (with the least root mean squared error less than 20 and 35, respectively). In general, it was concluded that the analytical power of corrected Ripley's K -function varies based on the implemented correction method and the type of investigated spatial pattern.

The possibility of making an adhesive free compressed wood with the dimensions of 30* 30*1 cm from the particleboard sanding dust was studied. The amount of sprayed water on the particleboard sanding dust was adjusted as 7, 9, 11, 13, 16 and 18 % of dry weight particleboard sanding dust. Test boards were manufactured based on 0.95 gr/cm3 target density, under press temperature of 180oC and 200oC. The boards were tested for internal bonding, modulus of rupture and thickness swelling. All tests were carried out according to the appropriate European standards. Results showed that mechanical and physical properties were considerably improved by addition of 18 % water at temperature 180oC. According to scanning electron microscope images, it can be concluded that this self-adhesion is based on the melting and flowing processes of some amorphous polymer materials such as lignin and carbohydrate. In addition, scanning electron microscope images showed that in particleboard sanding dust there is nano-sized particles, which play an important role in bonding quality. Continuous reaction of resin urea-formaldehyde in higher press temperature is another reason for increasing strength.

In this research, green composites were produced from poly (lactic acid) (PLA) and natural fibers by using twin-screw extrusion followed by compression molding process. Different bagasse pulp fibers including monoethanolamine (MEA), alkaline sulfite-anthraquinone (AS), bleached soda (BS), unbleached soda (UNS) and raw bagasse fibers (B) were prepared and compounded with polylactic acid. Thermo-mechanical properties, crystallization behavior and morphology of PLA and its composites were investigated. The results indicated that the tensile modulus of composites was increased compared to the neat PLA. While the addition of B, UNS, BS fibers caused a dramatically drop in tensile strength. In addition, the results showed that the crystallinity and dynamic mechanical properties of PLA were substantially improved by incorporation with natural fibers. However, depending on the pulping type, different improvements of the composite parameters were attained. It was found that MEA and AS fibers were more compatible with the PLA.

The main goal of this study was to explore the level of adding precipitated calcium carbonate (PCC) filler to the kraft fibers which treated by Layer-by-Layer (LbL) method. The kraft fibers treated by three layers of cationic starch-nanosilica-cationic. Then, the standard hand sheets (60±3 g/m2) were made from untreated and treated fibers. The results showed that by using 3-layers treating of kraft fibers, tensile index was improved from 23.96 N.m/g to 38.50 N.m/g. In addition, the burst and tear index was increased from 1.46 kPa.m2/g to 3.58 kPa.m2/g and 9.14 mN.m2/g to 15.99 mN.m2/g respectively. Also, the SEM images illustrated the fibers surface gelation due to the cationic starch absorption and an improvement of bonded area in fibers network. Furthermore, the three levels of PCC filler (5, 10, and 15%) were added to the 3-layer treated kraft pulp and strengths loss was evaluated and compared to the untreated pulp. Tensile, burst, and tear index were measured and they were 24.01 N.m/g, 1.20 kPa.m2/g and 9.49 mN.m2/g respectively by adding 10% of filler. According to the ANOVA test, the results revealed that it is possible to add 10% of PCC filler to the kraft pulp which treated with LbL method. Furthermore, SEM images indicated the retention as well as relatively uniform distribution of the PCC filler in the fibers network particularly in the area which impregnated with cationic starch.

In this research, the hydroxyl (OH) accessibility in the beech, spruce and pine wood was measured by impregnation of the wood specimens with heavy water (D2O) (deuterium exchange). After impregnation of wood specimens with heavy water and drying in a vacuum oven, the relative hydroxyl accessibility (% accessible hydroxyl groups) was determined with ATR-FTIR spectrometry by calculation of the integrated peaks for the OH and OD stretching vibrations at wavenumbers of 3500 and 2500 cm-1, respectively. The absolute accessibility (mmol hydroxyls/g wood) was determined using an advanced dynamic vapour sorption equipment, (DVS-ET1) by measuring the increased dry mass of the sample due to deuteration after conditioning with heavy water at 95% RH. The results showed that the relative accessibility was not affected by the wood species and its extractive content and more than half of the hydroxyl groups could be accessible. The absolute accessibility in spruce was higher than that in beech. For spruce wood, the early wood had less accessible hydroxyl groups than the latewood. The poor linear correlation between the hydroxyl accessibility and equilibrium moisture content (EMC) confirmed that the moisture absorption by wood was not controlled exclusively by the hydroxyl accessibility.

The aim of this study was synthesis of canola and sunflower epoxy resins using their corresponding oils. The acrylic epoxy resins from the canola and sunflower oils were successfully prepared. The oils were epoxidized by using the hydrogen peroxide (H2O2) in a proportion of 1: 7 from (C=C: H2O2). The content of epoxidized Oil was studied by determination of epoxy value using titration method and fourier transform infrared (FT-IR) spectrometer. The results showed that the epoxy value was 6.25 and 4.53 % for canola and sunflower oil respectively. The canola and sunflower epoxidized oils were transformed to the acrylic canola and sunflower epoxy resin and chemical structures of the resins were investigated by FTIR and proton nuclear magnetic resonance (1H NMR) spectrometer. Furthermore, the viscosity, molecular weight and special weight were measured. In addition, the content of fatty acids in the Golestan zone canola and sunflower oil were determined by the GC instrument. The results illustrated that both resins had several unique properties such as eco-friendly, non-toxic, economy, availability, and high adhesion.