Journal of Wood and Forest Science and Technology
Year:2009 | Volume:16 | Issue:1|Papers Count:8

This study was aimed to investigate the effect of altitude on fiber characteristics, chemical composition and kraft yield pulp of Brutian pine. Wood samples were collected from different altitudes as 450, 750 and 960m of Arabdagh plantation, located in Kalaleh region in the northeast of Golestan province. Three healthy sample trees of Brutian pine were cut from each altitude. Maceration of earlywood and latewood were conducted using Franklin method, then fiber characteristics (fiber length and diameter, lumen diameter and cell wall thickness) were measured, using light microscope. Tappi test methods were used to determine chemical compositions such as cellulose, lignin, ash and extractives content in wood. Kraft pulp was prepared at these condition: AA, 18 and 20 percent; time 60, 90 and 120 min. Analysis of variance of fibers characteristics and chemical composition was conducted using completely randomized design, then mean values were compared, using Duncan test. Factorial experiments were used for comparison of the pulp yields and kappa numbers. Results showed that between early wood and late wood fibers characteristics of three altitudes significant difference exists with level of 5%. Measured fiber from altitudes 750 and 960m were maximum and minimum values, respectively. Cellulose content was significantly higher in altitude 750m, while lignin and extractives content were higher in altitude 960m which showed significant difference with level of 5% by comparison. Ash content was not significantly different for three altitudes. Obtained pulp from altitude 960m, because of lower kappa number is considered as proper pulp for production bleachable strength pulp, if suitable refining is carried out. On the other hand, obtained pulp from altitude 750m, because of suitable yield, can be used in different kinds of paper production such as linerboard and different wrapping paper.

Plant growth in any region is influenced by environmental factors. In order to determine potential habitats of species, it is required to study ecological needs of the species and climatic-edaphic properties of the region. In this study, potential habitats of three Mediterranean and industrial arbor species including Cupressus sempervirens, Pinus nigra, and Olea europea were investigated in Armand, Lordgan, Chaharmahal Bakhtyari Province, using GIS and RS techniques. To provide information layers, different maps of the study area including topography, geology, and climate and soil maps were collected and digitized. Other layers such as rock outcrops, forest cover, irrigated arable lands, dry farming, rangelands and shaded areas were extracted using Landsat TM data. Referring to scientific articles and references, 14 Mediterranean and industrial arbor species were selected and their ecological needs were determined. Ecological needs of these species and properties of the study area were considered to provide information layers. The results showed suitable potential habitats for Cupressus sempervirens to be 1150 hectares, for Pinus nigra to be 996 hectares and Olea europea to be 5199 hectares.

This investigation was carried out in the 2nd district of Vaz research forest, located in Chamestan city (Mazandaran Province). Inventory grid was designed by a random-systematic method with dimension of 150×200 meter and sample circle plots with radius of 17.84 meter. In each sample, some qualitative and quantitative factors of the trees and site were recorded. In order to recognize the type, total surface average equal to trees basal area in sample plot and TWINSPAN (Two Way Indicator Species Analysis) were used. Forests stands were grouped and classified into seven group types as the following: 1-Fagus-Acer velutinum associated with Carpinus betulus, 2-Fagus-Carpinus associated with Acer cappadocicum, 3-Carpinus-Parrotia associated with Acer velutinum and Acer cappadocicum, 4-Carpinus-Parrotia associated with Acer velutinum, 5-Parrotia-Carpinus associated with Acer velutinum, Alnus subcordata and Diospyros lotus, 6-Alnus associated with Carpinus betulus and Diospyros lotus and 7-Zelkova carpinifolia. Biodiversity of forest trees were tested by two species richness indexes (Simpson, Shannon-Vinner) and evenness indexes (Simpson, Smith-Wilson). Then, all of the types grouped in the same ecological categories were analyzed by T-test. In order to test the effective factors on biodiversity index, multiple linear regression model was used. The results showed that biodiversity in the above types of 1 & 3 were more than 2 & 4 types. Moreover, the effect of evenness index on biodiversity was more, because although the types 1 & 3 had less species but high diversity. The relationship between biodiversity index, physiographical factors with qualitative and quantitative stands characteristic in forest types showed that altitude effect had negative trend on the biodiversity indexes. In addition, previous trend was not linear in all cases. The slop factor caused to increase the mentioned indexes, because the stands are damaged in the low land areas and are eliminated in the high land areas. Totally, biodiversity dependes on different factors, but this research considered some of them, and generally biodiversity phenomenon is dynamic and different in the level of ecological succession.

Forests as a part of renewable natural resources play an important role in national economic growth. In order to consume this national treasure, exploitation of these resources is allocated to forestry operators on the basis of forestry plans. The Ex-post analysis of these plans is necessary. The purpose of this study is to assess the first revision plan of Dr. Bahramnia Educational and Research Forest (Shastkalate, Gorgan). This was done with considering real expenses and revenues and machinery value at the beginning (1997) and the end (2006) of forestry period. The assessment was done by using net value of project to ex-post evaluation and deriving the internal rate of return (IRR) of the project. Findings show that more than 99 percent of all revenues are for wood products due to its sales. Costs and revenues show, with a fluctuation during the decade, a rising trend. The highest and the lowest percentage of all costs are as follows: labor 36.5%, taxes and owner's share 24.1%, preparation and transportation 19.1%, and the rest for road building, machinery, administration, etc. 54.7 percent of total sale was related to the industrial wood that was due to an increase in the price of wood unit. Based on the results of financial analysis of this the project, it is estimated that the internal rate of return is 41.12 percent. Therefore, it is concluded that this project is a profitable project because of the access of this rate from common banking interest rates. Finally, some strategies are suggested to decrease costs and increase revenues in order to improve the present situation.

This research is carried out in Caper habitats of Khalij-o-Omanian region in south of Iran.  Eight sites were chosen and 24 plots each containing at least three Caper trees were established. Some silvicultural characteristics of trees as well as physical and chemical properties of soil were studied within the plots. Totally 67 Caper trees were studied quantitatively. Generally, Caper habitats in Hormozgan province have  arid and warm climate, low annual precipitation (141.5 mm), high temperature (maximum 44.8oC) and high relative humidity (>60%). The results showed that Caper tree (Capparis decidua (Forssk.) Edgew.) had a short tree and shrub form with canopy diameter more than its height and numerous suckers in young stage, which changes to tree form (max. 9 meter height) with one trunk (max. 1.8 meter trunk height) and less suckers in old stage. Soil of Caper habitats were loam and silty loam, saline, calcareous and with very little organic matter. Electrical conductivity of the studied soil was 0.6- 22.5 mmohs/cm, pH=7.3-8.1, TNV=19.6-34% and organic carbon=0.2-0.5%. The quantitative datas shows 42-105 tree ha-1 with 12 to 50.6 suckers (coppices) per plot, 3.2-4.5 m height, 9-31.3 cm diameter, 0.03-0.3 m trunk height and 3.7-6.5 m canopy diameter. Caper trees flush (new branches with tiny leaves) with beginning of rainfall (autumn–winter) and leaves abscised later in old branches. Old branches were woody, green and able to photosynthesis (similar to leaves). Considering all soil and silvicultural characteristics, one can conclude that the Jagin site could be distinguished from other sites because of soil richness, highest trees, thickest trunks and coppice stools, widest canopy diameter and less number of root suckers.

Construction of forest roads disorders the natural trend of water movement. It is vital to make ditch and cross line drainage culvert to prevent the area from being destroyed and conduct the water of streems and vallies. Determination of culvert diameters depends on the information of area discharge, physiographic characteristic, vegetation cover and site land use. In order to determine the amount of sub basin water discharge and the diameters of cross culvert in forest roads, for drainage operation and preventing from land destruction, a study has been carried out in Zalemrood watershed area in 27 sub areas which were created using Arc view software. The flow intensity of each sub area has been calculated as foot cube per second, using curve number method (CN) with time intervals of 25 year. Then the diameter of each sub area culvert was achieved, using cement culvert diameter determination graph. The results show the dimensions of the culverts were different from 38 to 156 centimeters. To achieve the best culvert dimension in mountainous area, the culverts sub area with diameter less than 60 centimeter were combined together so that the best diameter can be achieved for each sub area. Thus, according to the results, in some sub basins the diameter of the available culverts were not equal to the calculated diameters of culverts and need to be increased or decreased, which leads to decrease in the costs of culverting and fixing the roads having improper culverts.

In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of kenaf (Hibiscus cannabinus) bast soda pulp was investigated. Kenaf bast was soda pulped using 20% alkali in 170oC for 1 hour. Produced pulp had 55% yield and kappa number 12. Bleaching process included two stages: 1-chelating 2-alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing peroxide level. Data also showed that increasing of the percentage of caustic soda does not have any effects on the brightness and kappa number of the pulp, but yield decreased. The data related to 3% caustic soda and 5% peroxide treatment without chelating stage, indicated that initial chelating stage significantly affected on the brightness, kappa number and yield of the bleached pulp, and this treatment had the lowest brightness and the highest kappa number and yield among all treatments. Finally, 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (73%) and the lowest yield (92%), and 2% caustic soda-5% peroxide treatment with initial chelating stage which had 70% brightness and 95% yield was selected as the best treatment, due to the appropriate brightness and yield values and lower consumption of the bleaching chemicals.