نشریه علوم و فنون منابع طبیعی
سال دوم شماره 3 (پاییز 1386)

Different methods of wood transportation have different effects on residual stand. For this aim, investigation on the effect of aerial transportation by helicopter on residual stand in winter 1384 in sector 2 forst ,cathment basin 38 ( Palat chshme_ Gerdelapi ) Nowshahr grand administration area to realize the effect of this transportation method that performed in 1374, were studied . By primary studies and performing random statistical method and selective 20 sample plot (10 R ) and 20 microplot with central joint with sample plot (1R) , to take measuring all trees and seedling species separately, diameter, height, number and kind of damage in area that helicopter had activity and control area. According to Statistical analysis in area that helicopter have an activity , because of violent air flowing and contamination resulting from helicopter activity, 55% number of seedling decreased than control area and also because of helicopter's vertical force, existing regeneration that through aerial transportation have diameter less than 20 cm, amounting to 20-32 % completely inclinated, also with according to logging by cable and raising timber from ground by helicopter 21 % of residual trees in stand that have diameter over than 20 cm damged such as cracked crown, branches and peeled bark.

In order to the study of Biological conditions of hornbeam specie, also the study of its quantitative and qualitative characteristics in the forests of the watershed of Golband region in west of mazandaran, three germination sites in three height Levels (less than 700 m,700 to 1400 and more than 1400 m. From sea level) and in each height from sea level, three net stand of hornbeam, Beech tree- hornbeam site and mixed hornbeam were selected. In each germination site , two sample Piece , with 400 square meters (20 m×20m) , at least 18 sample pieces for study were selected . The results of this study showed that hornbeam in different environmental conditions sepreated. This species from down up to high elevations and in different slopes has distributed. The general results reveled that hornbeam tree is a species with fast growth, and is phototropic which in deep and cold soils with preservation more water capacity it has suitable conditions for growth. The soil texture is loamy, clay loamy. And acidity ranges from 4.73. To 7.5. The average number in each Sandy clay loam and sample piece is 18 single roots in each sample piece. The average of diameter at breast height (DBH) 28.28 cm, the average of cross section in each hectare is 0/2245 square meters in hectare, the average of mean diameter of crown in hornbeam tree is 6.46 m. the average of whole height is 20.27m ., the average of trunk height is 11.46 m . Generally, out of 199 single root of hornbeam under the study, 157 single root have plumb line trunk, 175 single root have trunk without twist, and 178 Single root have asymmetrical crown. The quantitative and qualitative condition of regeneration hornbeam in region under the study is not satisfactory.

The recognition of the plant coverage in each area is the basis of ecologic studies; also it plays an important role in the environmental life management. The goal of this study is introducing the trees and shrubs spices in beech sites of Kojour as plant units. In this study, at first, the land form units were divided to topography maps (1:25000), Then at each land unit the trees and shrubs were recognized through forest course and a circular plot (1000 m2) was selected regarding to stand conditions (31 plots). According to physiognomic conditions the plant units were introduced. The results intvoduced as types of the trees and the shrubs at each area regarding the altitude, aspect and percent of slope. The results indicate that the distribution of spices, the mixture of the trees and the forest types of the area are affected by ecological Factors. There are better conditions in the forest stands, which are placed on a high altitude. The high quality spices are found in the northern aspects because of the suitable humidity where as destroyed stands are seen in the southern aspects. Going far from the villages, the forest types change by ecological Factors.

To know and study the measure of tree characteristics can be a good guide to adopt forestry ways and correct methods in their culture to attain the objectives of tending of forests. In the region of Gombol from the Lahijan forests, 121 trees from the Alnus species were randomly Selected and their characteristics such as log diameter, diameter at breast height, whole height, height and diameter of crown, were measured. Results of this study showed that the relationship between diameter at breast height and crown height was increasing but it was decreasing from the layer of 70 cm. Also from the statistical point of view there is a Significantly difference between diameter at breast height and crown diameter of Alnus trees in the region studied. By increasing diameter at breast hight, the slenderness coefficient is decreased. Based on this coefficient, nearly 14 percent of trees were unstable and 86 percent of them had partial and suitable stability. Also Alnus species in this region was very unstable over the diameter of 35 cm and it is stable from the diameter of 35 cm or so. The relationship between diameter at breast height and trunk diameter is linearly increasing. As a biological conditions, Alnus species in this region contains 4. 8 6. 4 soil pH and it lives in the soil texture that is heavy to half heavy without slip and contains safe lower layer.

Animal logging with proper designation and management was being used from many years ago as harvesting system with low undesirable effects. Therefore, we studied the effect of animal logging on forest soil, in district 9 of Shafaroud. Two type of soil samples were used to estimated soil compaction caused by animal logging: depth 0-10 cm and 10-20 cm from soil surface. These samples were collected by standard steel cylinders along tree 100 m distance by 50, 80 and 120 m3 out put volumes. Result showed that compaction has no significant difference with those three distance with different output volume .therefore, we can found that , soil compaction caused by animal logging occur in primary trips, and compaction was slightly increased by increment of output volume (in consequence, increscent, of animal trips) depth 0-10 cm was mast effected by compaction.

In this research the identification method of Iranian hardwood timbers and indigenous softwoods via cross section characteristic and with use of lens have been studied. For this aim at the first, cross section of samples have been surfaced with sharp razor and then with different magnification and have been photographed via loupe. Results showed that apart of colour and texture of species, the presence or lack of resin canal is main parametr of softwoods genus identification. Vessel arrangement, tyloses in early wood vessels and distinct and indistinct of rays are most important identification factor in ring-porous hardwoods identification. But presence or lack of banded tangential parenchyma, distinct or indistinct of rays and also vessels arrangements play important role in identification of diffuse-porous hardwoods identification.

In this study , three planted maple species trees were randomly cut down from Chamestan Forest . Samples were used to measure the chemical composition according to TAPPI standard and sodium chloride methods, then data were statistically analysed. The experimental results showed that the variation of alpha-cellulose content has regular increased from pith to bark in the radial Axis hollo cellulose and ash content has not regular decreased, lignin extractives and pH, Content has regular decreased, and 1% NaoH Solubility has decreased. In All properties, Hollo cellulose and Ash significantly difference were observed, except alpha-cellulose The results in this study at comparison to accomplished studies from natural maple and another species showed that utilization of the planted maple can suitable in wood and paper industries and it can important role to decrease raw material problem and development of the new comer Iranian wood and paper industries.

Increasing the river's pollution and Reducing their quality is management esseutial for their usage. notifies management. The Sardabrood river which is taken into account as one protected river in the Caspian sea- northern Iran- flows through variety ecosystems. Therefore, for the management of this river, assessing the quality of this river related to the present ecosystems surrounding its basin is the basic task which this research presents. First, employing landscape ecology approach, four major landscapes were distinguished which result in river zoning. Those are consist of the Mountain, Kelardasht plain, Forest and the Chalous lowland landscapes. Then, in two seasons, winter with the lowest pollution rate and summer with the highest pollutants; sampling was carried out in the discharge at the strategic locations of each landscapes. Consequently, eight stations were selected and fourteen parameters including water temperature PH DO B.O.D C.O.D EC Turbidity NO2 NO3 NH4 Caco3 CL T.S.S T.D.S and four toxic metals (i.e., Fe Ba Pb Cr ) were measured. The fuzzy sets theory was employed for the analysis of the data related to each landscape in order to doing river quality zoning. Results showes that the river's quality is significantly affected by each ecosystem and its water quality and quality on Virgain landscape is very sufficient. however in human landscapes, quality is associated with the intensity of human activities. River quality in the Mountain landscape is the best, in Kelardasht plain landscape is moderate, in the Forest landscape is as well and the Chalous lowland landscape has poor quality.