نشریه علوم و فنون منابع طبیعی
سال هشتم شماره 4 (زمستان 1392)

The present investigation was done in forest region number one in the south eastern part of Sari city. According to this, the effect of utilization and wood transportation, which has been done for many years, on element, site and forest, herbal layer and soil features ( in two different depth from 0 to 10 cms and from 10 to 20 cms ) was measured in skidding ways of a forest region. As a result, the skidding ways and also the region which has not been touched was considered for sampling on seven different places every 10 meters. There fore, seven samples of any herbal layer, seven samples of soil up to the depth of 10cm and seven samples less than 20cms was provided. Each sample of herbal layer was in 1 m. Soil compression on the same points which the elements of forest and herbal layer was taken, on the same two mentioned depth was done. At the end, it is concluded that soil compression which is created by ground skidding increases the micro lithic soil and soil density decreases perforations and amount of humidity. The bad effects of soil compression was mentioned by a lot of researchers before.

We studied the effect of different slopes and aspects on some qualitative and quantitative characteristics of Quercus persica in BadrAbad region of Lorestan Province. Thirty six circular plots each with the area of 1500m2 were selected in a random-systematic method. We measured crown diameter, diameter at breast height, number of shoots per each stem, quality of stems, and the number of all Q. persica coppice and seed grown stems within the plots. The results showed that higher crown diameter of coppice elements was in western, eastern, southeast aspects and it was lower in south, north, and northwest aspects. Diameter at breast highest was highest in north, and southeast aspects and it was lowest in south and northeast aspects. Q . persica had the highest rate of coppicing per each stem in west and northeast and lowest coppicing rate of this species were found in north and south aspects. The highest and lowest number of healthy stems of Q. persica were in north and southeast respectively. The density of Q. persica in slope range of 16-30% was highest and it was lowest in the range of 10-15%. The slope range of 16-30% had also the highest number of non healthy stems of Q. persica. In general, 90% of all measured stems of Q. persica were healthy. Those trees of Q. persica with crown diameter range of 2-5 meter the highest frequency and those with crown diameter of higher than 6 meters had the lowest frequency in the study area.

This research was conducted in the forest Golband Veysar in forestry projects. For this study3piece samples one hectare, square shape and with dimensions 100×100m was selected in areas development and characteristics of all forest trees that have a diameter greater than 7.5cm consisting type - species diameter at breast height was measured. To verify the vegetation sub-sample plots at In each sample five 2×2m sample plots were harvested at the center and four corners. The results showed the number trees in of the initial stages, optimal and Decay gradually decreased. Maximum number of trees in diameter classes, the initial stage and decay stage the floor and 10cm diameter and 15cm diameter class was the optimal stage. Most number of the Elevational classes at Stages initial and decay at 10m floor And In the optimal stage The floor was 15meters. Maximum volume per hectare was belonged to optimal stage. Most number and volume dead wood at initial stage Was observed. Result Indicators Biodiversity revealed that Highest species diversity indices Shannon – Weiner and Simpson At decay stage.

Following the destruction of vegetation and increasing soil water losses in watersheds violators of the last decades due to uncontrolled exploitation and unethical's resources has intensified. This contributed to increased life expectancy and reduced flood sedimentation tanks Dam reservoir lower production and production losses in the national capital. This study aims to assess the impact of some measures of biological functions (forestry, pastoral work) in varazan village in mazandaran kojoor area planted seedling in previous years has been chosen and checked. In thisresearch andhepothese are defined such as :Does the implementation of biological measure is the reason for soil erosion is reduce. How these factors efecton the establishment of vegatation condition will get better with time or not? is conducted on erosion and sediment yield. • .This information is necessary to achieve applicable results before and after project implementation and evaluation of biological placed. • All information on this project as the basis for the study of field work for this study has been Measure implemented after the study is the most important part of the comparison In this study, the relationship of the natural soil is universal formula. Kidneys cases mentioned in the Universal Soil Equation (A = RKLSCP) has been studied. The maps of the study area classified into 14 units (based on the direction and velocity) on the map, we proceed to the grid. Then the plots in a randomized systematic sampling grid based on the purpose of determining the nature of the plot, we would like to implement. Methods based on field sampling and density of vegetation soil profile and other relevant information. To soil erosion and sedimentation. Recognizing the important measure as well as other items used in the Universal Soil equation. Fraction of vegetation cover systemic random line transect method, 44 samples were taken Estimating canopy as well as 14 hidrologycal units (per unit of work) is taken to determine the direction the item was sent to the Laboratory of Soil Science. Precedent canopy and density of 62 percent to 84 percent increase then the result of calculations obtained with the deposition rate of the output area of 5.8 ha to 4.3 tons per hectare This result means that the corrosion rate has decreases with increasing vegetation therfor the hypotesis was accepted.

The quartered neighbor sampling method is one of the distance sampling methods which is used for measuring the density of vegetation quantity. In this study, first a region about 40 hectares is designated and then 40 point have been randomly selected for sampling in three different methods (the nearest neighbor method, the point-centered quarter method, and the combination method). Since the most important factor in estimation the three density is the average place density, the correlation of average distance among three methods have been calculated by quadrat. The results have shown that among distance methods, just the nearest neighbor method has a significant correlation with quadrat method. The statistical analysis among the three methods with quadrat method has shown that the combination method benefits a higher precision than the two other distance methods. Moreover in estimation the density in a forest with random distribution, the nearest neighbor method provides more acceptable results and has a density near to density of quadrat method.

(Conocarpus erectus L.), family (Combretaceae) Evergreen tree native to the tropical and subtropical regions and the world, is that during the recent years, in order to upgrade the level of the per capita environmental consequences and to prevent dust from the Persian Gulf region in the South of the vast areas of Iran and has been planted because of low resistance and high temperature as well as the ability of this species in the rapid growth of the art form and the flexibility of the canopy is located, according to the case. Understanding the features and identifying the optimal anatomical characteristics of wood requires academic review it in order to exploit the scientific, is worthy. Hence assuming the anatomical specifications of changes on two timber not pruning and pruning on the tree, proceeded to identify a healthy disk and six wooden sections of the trunk of the tree and pruning trees have been pruned to three. Then by thin samples of microscopic Micron slices which they prepare and after staining with Sfranin by glue and Canada Astrablu Balzam on the Lam, glass established and according to the microscopic characteristics of hardwood provided by the Committee (IAWA) were described. As well as morphological specimens were prepared in accordance with the method of fiber length up to Franklin, cell wall thickness and diameter of the fiber was determined by the cavity. The results of this study showed that pruning can clearly limit the circle of life forms, vascular elements, particularly the placement order and thus the thickness of the longitudinal parenchyma and abundance as well as an increase in the length of the wooden rays, tree pruning, is in effect.

This investigation reveals the application of lignocelluloses extract, which contains the Soya stem in producing Particleboard. To make the particleboard, Soya stem and industrial wood particle in combination with 4 components (1.Soya stem 100% 2. Soya stem 75% and industrial wood particle 25% 3. Soya stem 50% and industrial wood particle 50 % 4. Soya stem 25% and industrial wood particle 75%) and types 10 and 12 % resin consumption content in two press time ( 4 and 6 min ) have been used . The mixture of above elements produce 16 different combination, and for each combination 3 boards in total 48 boards were used. The result of physical and mechanical properties were analyzed using Randomized Complete Block experimental Design ( RCBD ) and the average use of Duncan Experimental Test groups . According to the results , it revealed that MOR and MOE of boards have significantly been increased by increasing the amount of resin consumption from 10 t0 12 % .On the other hand , the results showed that adding Soya stem to wood combination and decreasing the industrial wood particle lead to increasing the MOR and MOE of boards and these features are within Iran standard while using 100 and 75 % of Soya stem in boards’ making .Mutual effect of resin consumption amount and press time on MOR of boards is meaningful and by increasing the press time from 4 to 6 min while 12 % of resin consumption , MOR of boards has been increased . The results of this investigation showed that increasing the resin consumption amount leads to boards’ IB improvement. In addition, by increasing the press time with 10 % of resin consumption amount , IB of boards has been decreased while it has been improved significantly with 12 % of resin consumption amount . But all of the average amounts for produced boards’ IBs have been higher than standard level .Results obtained from the effect of variable factors on TS 2,24h showed that increasing the resin consumption amount has statistically decreased TS2,24h and also WA2,24h in a meaningful level . These results also revealed that wood combination doesn’t have meaningful effect on these features while adding press time from 4 to 6 min has increased WA24h of boards meaningfully .

In this study, influence of three different joint types with two glue coverage rates (Full glued and low glued ) on dynamic Young's modulus using flexural vibration method in free-free bar test was evaluated. Rectangular specimens of 2×4×36 cm (T×R×L) were prepared from intact eastern beech (Fagus orientalis L.) wood. Three types of joint were considered, 45o scarf joint, 30o scarf joint, and finger joint at the middle of the longitudinal-radial plane. Every set of the specimens, before and after joint creation, was individually subjected to flexural vibration test. The results revealed that the type of joint had not significant influence on dynamic Young's modulus. Furthermore, there was no significant difference in modulus of elasticity between solid beam and fully glued specimens in different joint types. Although, by reducing the glued coverage in different joint types, a significant reduction in the dynamic Young's modulus was observed.