نشریه علوم و فنون منابع طبیعی
سال هشتم شماره 3 (پاییز 1392)

The present study was carried out to investigate some of qualitative and quantitative characteristics of Manna oak species (Quercus brantii), of Dasht Laleh region in Andimeshk township. 36 sample plots, each 1500 m 2, were established in three land forms (ridge, valley and slope) in four aspects. Quantitative and qualitative characteristics of individual trees were measured and recorded within the sample plots. Results showed that the highest frequency of stem number was recorded in diameter classes of 20 cm. The mean dbh, basal area and number of Hectare were 29.54 cm, 5.6 m, 69, respectively. The mean height and dominant height of the stand was 6.16 and 14.4 m, respectively. The mean slenderness coefficient was 20.86.The results of qualitative characteristics showed that the healthy and non healthy crown trees of the stand were 78% and 22%, respectively. 60.5% of the trees were vertical and 39.5% of them were curved. In addition, 50.8% of trees were, grade one, 45.9% grade two and 3.2% of them were grade three in trunk quality respedtively. Generally in terms of the condition of qualitative and quantitative characteristics of oak trees, the northern aspect is evaluated as more suitable sites.

The purpose of this study was to evaluate soil invertebrates diversity in pure and mixture Zelkova stands in Neka forests (Mazandaran-Iran). at the time of study the stands were selected from undisturbed forests. For this purpose, invertebrates were collected in mid-summer, using 20 core soil samples (81 cm2 cross section) to a depth of 10 cm. The invertebrates were extracted by Berlese funnel and counted by Binocular. In addition, 20 soil pits of 100×100 cm2 with 10 cm and 30 cm depth were taken and adult earthworms were collected by hand counting. The results of this research showed that the soil invertebrates diversity (Shanon and Simpson index) with species richness (Margalef index) and species equatibility (Heip index) in the mixture stand of zelkova were greater than the pure stand of zalkova. Of course it must be mentioed that these differences were not statistically significant. Fur the rmore, the frequency and biomass of earthworms in the mixture stand of zelkova was significantly more than the pure stand of zalkova. The results of this research has emphasized the reinforsment of mixture stands in tending operations.

Remote sensing data due to its specific characteristics, including broad coverage and repeatability play an important role in forest type mapping. The purpose of this study is to investigate the possibility of SPOT5 satellite images for the determination of Armaedeh forest types in the northern Zagros forests. Ground data were provided by systematic random sampling method with 448 plots of 0.1 ha. Original bands of Spot5, different vegetation indices in order to reduce the reflectance impact, and the first component of the principle component analysis, were used in the classification process. Maximum likelihood, Artificial Neural Network, and fuzzy methods were used to classify forest types. The results showed that using the quantitative and the spectral data in the artificial neural network approach in comparison to other methods has a greater accuracy. Overall, the results indicated that, the SPOT5 satellite images do not yield suitable results for distinguishing forest types in the study area. The reason may be because of pointed low grade canopy and low density of trees.

The purpose of the present study is to compare the leaf nutrients in pollarding and no-pollarding areas of Oak trees in Sardasht forests, northern Zagros. Six closed stands (three pollarded and three no-pollarded stands) were selected of the same physiography, elevation and climate conditions. Random sampling method was applied to collect the data. The leaves of 10 trees from Quercus brantii and Q. infectoria (in total 60 trees) were collected in two periods, including after pollarding (first period) and at the end of the growing season (second period). After mixing the leaves, three samples of each species randomly were selected and their carbon, nitrogen, phosphorus and potassium were measured. In addition, T test was used for statistical analysis. Results showed that there was no significant difference between pollarded and nopollarded areas as well as between first and second periods for leaf nutrients of Q. infectoria. On the other hand, there were significant differences for nitrogen and phosphorus between pollarded and no-pollarded areas and between first and second periods for leaves of Q. brantii. There fore, the phosphorous and nitrogen of pollarded area were more and less than those in no-pollarded area, respectively. Results showed that Q. brantii is more sensitive than Q. infectoria, but further studies are needed to obtain more accurate results.

The effect of tree age on the anatomical, physical and chemical properties of P.euroamricana and P.nigra var.betolifolia wood was investigated. Four trees for each species at the age of 5-9 years were randomly selected and felled at fast growth poplar colons adaptation experiment site at Alborz Research Center. Then the anatomical, physical properties and chemical components of these poplar species at two ages of 5 and 9 years old were determined. The results showed that in both species, the average fiber length increases from pith to outer portion of stem, indicating that the selected trees from both species are still in juvenile wood period. The shortest fibers (0.863mm) were measured from P.nigra wood harvested at the age of 6 years old and the largest fibers (0.978mm) were found in P.euroamricana wood at the age of 9. Both dry and critical density of wood from 9 year old trees were higher than other ages and the dry density varied between 0.36-0.42 g/cm3 and the critical density varied between 0.32-0.37 g/cm3. The results of chemical analysis showed that 9 year old P.euroamricana wood contained the highest of cellulose (54.33%), lowest content of lignin(21.33%), and highest content of both extractives (2.42%) and Ash(1.21%).

This research was carried out to identify and compare the chemical component in the extractives of bark and wood from willow. Willow tree is one of the fast- growing trees in the country. The extractives soluble in acetone was measured based on TAPPI standard, and then was transfered to the ballon and then the BSTFA catalyst was added and transfered to the GC / MS injections. Identification of components was done according to the rerention time curve, calculation of Kats correlation and Adams table. Out of 13 components in the bark of willows and 31 components in that wood, 9 canstituents such as Styrene, Decane, 1_ Hexanol, 2_ ethyl, Do decane, Tetra decane, Phenol, 2,4-bis (1,1 dimethyl ethyl), Octadecane, Bis (2_ ethyl hexyl) phthalate and 1, 2-Benzene di carboxylic were detected as the same. The most important chemical component in the bark and wood from willow is Bis (2_ ethyl hexyl) phthalate which is higher in the bark compared with the wood. In addition, the value of Bis (2_ ethyl hexyl) phthalate in the bark and wood from willow is 98.46% and 97.46% respectively.

Phytoremedial is an emerging cost-effect and green technology in which screening plant species for growing in weathered conditions is of utmost importance. This study was carried out to investigate the refinement level of lead and Cadmium in polluted soils with tree species such as Pine (Pinus Eldarica Medw.), Cypress (Cupressus arizonica Greene.), Locust tree (Robinia peseudoacacia L.), Ash (Fraxinus rotundifolia Mill.) and Elm tree (Ulmus carpinifolia var umbraculifera Rehd.) in Tehran City. For this purpose in summer 2011 in polluted and controlled sites, Considering the main wind direction, one transect is selected and sampling from leaves and surface root was done with statistical method in completely randomized plot design repeated three times. Then lead and Cadmium content density in each sample was determined by Atomic absorption instrument model Perkin-Elmer 3030. Results indicated that the concentration of lead and cadmium in polluted sites was more than the controled sites. In addition, Also Pine, Cypress and Locust tree species have the highest translocation factor of Lead (3.49ppm, 2.99ppm, 2.82ppm) and Cadmium (3.35ppm, 2.83ppm, 1.92ppm) respectively. These three recent species are used to refine the lead and Cadmium polluted soils under the same conditions.

Referring back to effects of nano particles on water absorption behaviuor of composites, it is essential to study the effects of nano clay and foaming agents impacts on water absorption and tickness fixation of WPC composites. Therfore in this article the effects of nanoclay contains on water absorption and thickness swelling of hybrid wood flour/HDPE/MM nanoclay was investigated. Samples were tested in 24H period in 20 c water and 2 h in 100c water. Nanoclay diffraction was obtained with low angle XRD and morphologic behaviuor was obtained with SEM. The results showed that effect of nanoclay in 2h period leads to the increase of water absorption and thickness swelling, but in 24 H period leads to decrease of them. The reciprocal effect of nanoclay and foaming agent showed that using nanoclay in Wpc composite foam will decrease the amount of water absorption and thickness swelling in Wpc nanocomposite Foam.