فصلنامه جنگل و فرآورده های چوب
سال شصت و نهم شماره 2 (تابستان 1395)

This study was conducted for the first time in order to introduce the pioneer forest trees and medicinal sea-buckthorn (Elaeagnus rhamnoides) and determine the characteristics of the species seeds from seven provenances, including Iran, China and Tibet in the laboratory. After site identification of the species, seeds were collected from the regions including Alborz, Mazandaran, Eastern Azerbaijan, Western Azerbaijan, Qazvin, China and Tibet. The disinfected petri dishes were then placed into a germinator. The seeds were planted as completely randomized design in four replicates each with 25 seeds. At the end of seed growth periods, the traits including germination percentage, number of grown seeds, mean of germination time, germination rate, germination energy, seed vigor index, sum of plumule length, sum of radicle length, mean of plumule length, mean of radicle length, allometry, plumule number, radicles number and the ratio of radicles to plumule number were measured and/ or calculated. Averages of germination percentage were 90, 48, 95, 36, 33, 32 and 60 for Alborz, Mazandaran, Eastern Azerbaijan, Western Azerbaijan, Qazvin, China and Tibet, respectively. The maximum and minimum germination percentages were observed for Eastern Azerbaijan and China provenances, respectively. These indices were 54.1 and 20.6 for Eastern Azerbaijan and China, respectively. Allometry which is the ratio of the radicle length to the plumule length was maximum in Mazandaran with 2.4 and Qazvin with 0.95. This study showed that Seabuckthorn propagation by seeds is feasible and recommendable. Further researches are recommended on this valuable species due to its drought tolerance, nitrogen fixing ability and unique medicinal properties.

Pistacia atlantica subsp. mutica is one of the most valuable forest tree species in Iran that has been severely exploited for a long time. Therefore, understanding the genetic diversity of different populations can be an important step towards the development and restoration of the habitat of this invaluable tree species. In this study, in order to study the genetic diversity, 10 populations including 59 genotypes via 13 RAPD primers, totally 97 alleles were generated with an average of 7.46 alleles per primer that 100% alleles were polymorphic. Polymorphic information content (PIC) varied from 0.11 (primer Oligo342) to 0.21 (primer Oligo18). Marker index criterion ranged from 0.39 (primer Oligo203) to 4.35 (primer Oligo342). Abdanan population indicated the highest value of polymorphic alleles (57.73 %) and Shannon’s index (0.251) and the highest value of unbiased expected heterozygosity index (0.172) was observed for the Banaeh population. Whereas the lowest value of polymorphic alleles (13.40 %), unbiased expected heterozygosity (0.074) and Shannon’s index (0.081) were observed for out of Zagros population. Analysis of molecular variance (AMOVA) showed that a larger proportion of genetic variation (78%) belonged to intra-populations, while 22% of genetic variation was observed for inter-populations. Cluster Analysis could not completely separate samples and showed the lack of association between molecular diversity and geographic diversity populations. The genetic diversity among the evaluated samples can be promising for restoring the habitats of P. atlantica.

Willows due to the rapid growth rate, low nutrient requirements, resistance to many pollutants, and environmental stresses are ideal candidates for developing the landscapes and reducing the environmental degradation. The purpose of this study was to determine the response of Salix alba seedling to water deficit conditions. This experiment was set up as complete randomized design with five irrigation periods (2, 4, 6, 8 and 10 days) in three replicates (each replicate containes five pots) for four months. Results indicated a high survival rate for Salix seedlings, whereas under extremely drought stress (10-day irrigation) it was always greater than 73%. Height and collar diameter growth, above-ground and under-ground biomass, number of leaves and root volume decreased with increasing the irrigation period but no changes occurred in leaf area, specific leaf area, root length and root:shoot ratio. Regarding to the economy of water resources, 6- and 8-day irrigation periods, due to high survival (100%) and favorable growth of seedlings, can be considered for raising salix alba seedlings in this region and/or in climatic regions similar to the research site.

The research aims at studying the effects of mycorrhizal fungi (Glomus fasciculatum, G. mosseae and mixed composition) on growth, photosynthesis and nutrient absorption of Ziziphus spina-christi in Mehran greenhouse, Ilam province. The result showed that colonization rate in mixed treatment was more than pure treatment of G. fasciculatum and G. mosseae. Also, root fresh weight, stomatal conductance and chlorophyll a of mycorrhizal seedlings were more than non-mycorrhizal seedlings of Ziziphus spina-christi. The basal diameter, root dry weight, nitrogen content of shoot and phosphorous content of root in mixed and pure treatments of G. mosseae were more than G. fasciculatum and control treatment. Also, the photosynthesis and transpiration in mixed and pure G. fasciculatum were more than G. mosseae and control treatment. Mycorrhizal fungi had not significant effects on height (P = 0.269), shoot fresh weight (P=0.479), shoot dry weight (P = 0.697), chlorophyll b (P = 0.097), nitrogen content of root (P = 0.307), phosphorous content of shoot (P = 0.126), K of shoot (P = 0.667) and root (P = 0.638). The result of this study showed that mixed treatment, due to more colonization rate than other pure fungi, had more effects on growth and photosynthesis of Z. spina-christi.

Iron Wood (Parrotia persica) tree as a forest species has many applications in urban green landscape. However, its reproduction and seedling production have not been studied in Iran. Thus, knowing the type of cutting and hormone treatments to increase the rooting of cuttings can be very effective. Accordingly, annual and perennial cuttings were prepared in January and June, respectively. Cuttings were treated with different concentrations of Indole butyric acid (IBA) (0, 500, 1000 and 2000 mg L-1). Perennial cuttings were not rooted in the present study. The maximum rooting percentage was observed in the treatment with 2000 mg L-1 Indole butyric acid in annual cutting. There were no significant differences in root length and root number in the 500 and 1000 mg L-1 treatments. The application of IBA decreased significantly the rooting time compared to the untreated control. The results indicated the effective role of IBA in extending the rooting percentage of Parrotia annual cutting.

Genetic variation assessment in plant gene pools is the first step in identifying, maintaining and conserving the genetic resources and also the basis for breeding programs. Molecular markers provide the important tools to evaluate the genetic diversity in native plants. In order to evaluate the genetic diversity of 62 Iranian walnut seedlings, 10 SSR primer pairs were used. The used SSR loci generated 53 alleles. The minimum and maximum number of alleles were for SSR loci WGA69, WGA71 (4 alleles) and WGA1 (7 alleles), respectively. The most value of observed heterozygosity was recorded by loci WGA276. All used SSR loci showed deviation from Hardy–Weinberg equilibrium (p≤0.01). UPGMA cluster analysis using Dice similarity coefficient classified four groups among 62 studied walnuts. Population structure analyses using Structure 2.3.1 software identified two possible groups (k=2). Membership coefficient matrix and Fst values of the each identified subgroup indicated no remarkable differentiation among the subgroups. In conclusion, information obtained from the current study could be useful for identification of the seedlings with enough genetic distance in walnut hybrid production programs to exploit the heterosis.

This study aims at assessing the impact of land use change (from forest areas to forest parks) on some silvicultural characteristics of stands under recreational land use in Boloran natural forest park, Kuhdasht. For this purpose, three zones including non-recreation, extensive recreation and intensive recreation regions were chosen. In each zone 30 sample plots in a systematic random design (100 m × 150 m) were established. Within each sample plot, characteristics including tree density, frequency of regenerations, tree height, canopy diameter (small and large diameters), tree health and vitality, diameter at breast height (DBH) and number of sprouts in coppice trees were measured. Results showed that there were significant differences among the three zones in terms of density and frequency of regeneration. Also there were significant differences between intensive and extensive as well as control treatments in terms of canopy cover, with the lowest value in intensive recreation. Also there were significant differences between the zones in terms of tree height, and there were significant differences between extensive and intensive as well as control in terms of BDH of trees. Trees in extensive and intensive regions were of better vitality. The results also indicated that recreation whether extensive or intensive, has negative and unfavorable effects on the vegetation of the region and leads to changes in silvicultural characteristics of the stands.

Knowing and conducting studies on size characters of trees is essential for assessing the tree volume and/or other statistical parameters and also forest management. The characteristics of 529 trees including diameter at breast height (DBH) and total height were measured in an even aged Fraxinus stand for two periods from 2005 to 2012 in Chelir district, a part of experimental Kheyrud forest. Results showed that there are statistical correlations among the size characters of ash trees, therefore, mathematical-statistical equations could be developed among these characteristics This relationship was calculated for all trees in the stand as even-aged stand and then calculated for Fraxinus trees in the stand. There is an increasing power relationship between DBH and total height of all trees in the stands in two periods which is used for estimating the growth of total height of trees in next period. There are power relationships between size characteristics of Fraxinus trees in stand. The relationships between DBH and slenderness index for the first and second period are 0.014 1.475 dbh h d e and 0.006 1.210 dbh h d e , respectively. The vitality percentage curve was prepared for stand trees in diameter classes and the results showed that the periodic annual increment for Fraxinus tree is 3 mm. The research in natural forest stands and investigating their changes in a period, will show the path and proper method of management in accordance with the nature of the forest stands for maximum and sustainable production.

The use of heavy machinery in forestry operations such as logging has increased worldwide during the last decades. However, these machines may seriously influence the soil ecosystem as they induce rutting, disturbing the upper soil layers, and soil compaction. Severe compaction of soil adversely affects the growth of plants.This study was done by using a penetration resistance experiment in a greenhouse to test the hypotheses that increasing soil strength would affect adversely the seedling morphology (size) and growth (biomass) by changing the above- and below-ground patterns. We created four soil compaction intensity treatments. The lowest compaction intensity (no compaction, control), low, moderate, and high intensities of compaction were achieved by manually applying 3, 5 and 7 blows with a compaction hammer from a height of 20 cm above the soil surface, respectively. We studied the effects of soil compaction in a loam to clay-loam textured soil with optimal conditions of water on a continuous scale (0.1–1.0 MPa penetration resistance) on the growth responses of the deciduous Quercus castaneifolia (C.A.M.). 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 nonlinearly to increasing the soil strength. We conclude that growth of roots and height of oak seedlings are restricted with any increases in soil strength.

By Increasing demands on paper products and shortage of fiber resources, various strategies were introduced to meet the requirements. In this context, application of mineral fibers is a novel and growing approach. This study was aimed to Reduce the plant fibers by application of, mineral fiber in the papermaking system. Application of 0, 10, 20, and 30% Loadings of rock wool mineral fibers (RWMF) in incorporation with cationic starch (1%) on handsheet strengths, RWMF retention and total retention of stock were investigated. Results showed that bonding-dependent strengths, e.g. tensile and burst, were reduced by increasing the RWMF loading due to the low bonding ability of RWMF compared to the lignocellulosic fibers, while the tear index was increased up to 20% RWMF and declined then after due to higher intrinsic strength of the mineral fibers. Interwoven network creation of mineral-organic fibers during the sheet forming, enhanced the mineral and total retention value, however, despite priority of 30% over 20% substitution, there was no statistically meaningful differences. Therefore, with respect to severe reductions, the overall optimum substitution level of 20% for RWMF was reported in NSSC pulp production according to the obtained strengths results. In addition to economic and technical benefits derived from the mineral fiber application, the higher retention indirectly affects the environmental aspects such as reduction in suspended organic solids in process water, easier treatment of wastewater and lesser utilization of forest and other lignocellulosic fiber resources, all as the most important issues.

With the aim of identifying failure mechanism in oriented strand boards, failure behavior of wood strands under tensile load was investigated using acoustic emission technique. Resinated and unresinated strands were arranged at top, middle and bottom section of the board before pressing. Tensile and acoustic emission tests were performed simultaneously on treated and control samples. Using tensile test data, module of elasticity and ultimate tensile strength of specimens were determined. Acoustic emission data were used for calculating cumulative events, cumulative energy and amplitude of the signals. The results showed that increasing in amount of load and time resulted in increasing of the amount of acoustic emission cumulative energy, event and the maximum signals amplitude. The considerable increase of cumulative energy and events were achieved at the time of failure. The treatment conditions influenced the acoustic emission results and pressed specimens released higher acoustic energy and had higher cumulative acoustic emission events, in comparison to the other specimens. Generally, the magnitude of acoustic emission indices was proportional to mechanical properties such as elastic modulus and tensile strength indicating that failure in strands can be identified by acoustic emission.

In this study, compressed poplar wood was used to improve the strengths of wooden chairs. These chairs were compared to chairs made from uncompressed poplar wood. Wooden chairs were assembled with two types of traditional joints including mortise and tenon and wooden pins joints. The ultimate force was applied from the front to the back of the seat, were recorded according to American library association. The results showed that using of compressed poplar wood in manufacturing of the chairs led to a significant (95%) increase in strength properties. Compared to the chairs of raw poplar wood, strength was increased up to 57.5% and 64.12% at chairs manufacured with compressed poplar wood and joint of mortise-tenon and dowel joints, respectively. Joints of chairs made from raw poplar wood dislocated at back frames, but joint elements of chairs made with compressed poplar wood have lower move than other, and then the failure occurred at back frames. Generally, the chair made of compressed poplar wood and with mortise-tenon joint showed a highest mechanical strength. Moreover, wooden chair strength was improved by modification of wooden elements.

The current research was planned to investigate the effect of maleic anhydride (MAN) and glycidyl methacrylate (GMA) treatments on morphological and physical properties of the hornbeam wood-styrene composite. Test samples were divided according to ASTM D4446-05 to control and treated with MAN, ST, MAN/ST and MAN /ST/GMA. Treatment was performed by vacuum- pressure method using a experimental cylinder. The presence of styrene in the cell cavities, swelling of treated wood with MAN and interaction between MAN/ST and MAN/ST/GMA with wood cell wall were confirmed by Scanning electron microscopy. According to the results, density and weight of the specimens were increased as 73.47 and 79.91; and 5.95 and 11.9% by addition of MAN and MAN/GMA, respectively. Strong interactions between wood structure and combination of MAN/ST/GMA led toan improvement in the compatibility of polymer with cell wall and reduction in porosity of the treated wood. hydrophobicity and dimensional stability of wood polymer composites were improved as the result of modification with MAN and impregnation with ST, so that after the longest immersion time, water absorption and dimensional changes in MAN/ST/GMA with 42/44% weight percent gain, decreased up to 57/78 and 50.15% in comparison with the untreated samples. The highest anti-swelling efficiency was determined in MAN/ST/GMA treatment.

Sizing of paperboard has a distinctive position in packaging grade paperboard material. Optimization of sizing by alum-rosin at neutral pH in 4 layered paperboard (330 g/m2) wereevaluated in this study to find the optimum ratio of alum- rosin loading in the process. fixed amount of 1% cationic dispersed rosin together with alum as a fixing agent at 5 different levels of 1, 1.5, 2, 3, and 4% (based on OD weight of pulp) were used. Water absorption of top and back layers of the sized paperboard (Cobb test) and the paperboard strength and surface properties weredetermined. According to the results performance of rosin sizing system was improved by increasing the loading of alumledand led to a decrease in water absorption at top and back layers of the paperboard. Also, regarding to the unique improving features of alum in retention, bonding ability and charge neutralization of pulp ingredients, the strength properties such as ply bond, tensile and bending stiffness were improved, too. The results revealed that strength properties of cardboard are more affected by alum and rosin consumption levels than alum to rosin ratio and the best ratio of alum-rosin at the neutral pH, revealed as 2:1.

The effect of bleaching with sodium hypochlorite, as one of the most important parameters in obtaining optimal alpha cellulose pulp from cotton linter was studied. In this respect, unbleached cotton linter pulp was prepared from Parchin chemical industry co., bleached by HEA sequence in pH=9, 11 and 13; and then its chemical structures properties such as alpha cellulose, degree of polymerization, carbonyl groups, carboxyl groups, microkappa, ash content, acid insoluble materials and brightness were characterized. The lowest amount of alpha cellulose and lignin content were achived at pH=9,. Also, carbonyl and carboxyl groups were obtained in the highest level as well as sulfuric acid insoluble and ash content in this pH. By increasing of pH to 11, maximum amount of alpha cellulose and pulp brightness and also minnimum amount of ash content were obtained. In pH=13, less delignification was occurred while the lowest carboxyl groups were also observed in this pH. Therefore, according to results, pH=11 was suggested for industrial alpha cellulose production.

In this research, the chemimechanical pulps (CMP) with different yields were prepared by using the mixtures of constant raw materials comprising Iranian hardwood species such as hornbeam (44%), poplar (31%), maple (15%) and salix (10%). This research was aiming to study CMP pulp properties variations in yields lower than standard limit (85%). Four different yields (84, 80, 73 and 67%) were achieved by changing the cooking parameters including temperature, time and cooking liquor consumption ratio,. Freeness of the pulp, strength and optical properties of the 60 g/m2 handsheets were measured. . The results showed that the initial freeness was reduced with 17 unit reduction in CMP pulp yield, while all strength properties including tear, burst and tensile indices were increased to 42, 100 and 29 percent, respectively. The Brightness and opacity of the obtained pulp was reduced with reduction of yields and with 17 unit reduction in CMP pulp yield (from 84 to 67 percent), the brightness about nine percent and the opacity less than one percent were decreased.

Wood resources, non-wood plants and recycled papers are the common raw materials of papermaking. Shortage of raw materials, is a challenging problem in developing pulp and paper industry. In this study, Cladophora green algae was used as a new source of cellulosic fiberfor pulping and papermaking.. Cladophora algae was cooked with cold soda method and then was mixed with NSSC pulp at 10,20 and 30% loadings. structural and strength properties of the obtained pulp were studied and were compared with hardwoods NSSC pulp. The results showed that strength properties of the neat cold soda pulp from the algae were inferior than the corresponding properties of hardwoods NSSC pulp. Moreover, by incorporation of the green algae pulp to NSSC pulp, pulp strengths were reduced. so that, it is not a suitable source for production of fluting pulp.. According to the obtained results, Cladophora green algae cold soda pulp could be mixed in low percentages (up to 10 %) with NSSC pulp.

Gypsum-bonded particleboard panels were made from various mixture of bagasse (Saccharum ossicinarum l.) and wheat (Oryza sativa l.) straw particles bonded with different ratio level of particles/gypsum. This study examined possible feasibility of bagasse and wheat straw particles in the production of gypsum-bonded particleboard (GBPB). One-layer experimental GBPB with density of 1.05 and 1.20 g/cm3 29 were manufactured at bagasse/wheat straw ratio of 100:0, 93.75:6.25, 87.50:12.50, 75:25, 50:50, 25:75 and 0:100 using two particle/gypsum compositions of 1:2.75 and 1:3.25 and density of 1.05 and 1.20 g/cm3. Modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond (IB) characteristics of the boards and gypsum dough hydration process were evaluated. statistical analysis was performed in order to examine possible feasibility of these agricultural residues in commercial GBPB manufacturing. hydration results showed that , using lignocellulosic materials with higher extractives led to a reduced hydration temperature and increasing of hardening time of the mineral . The experimental results have shown that the MOR and MOE of boards containing 0%, 6.25% and 12.5 % wheat straw with LR/G ratio level of 1/2.75 were higher than those of manufactured panels.. In general, boards with a higher amount of bagasse ratio showed superior strength properties.