نشریه علوم و فنون منابع طبیعی
سال چهارم شماره 3 (پاییز 1388)

Afforestated projects have had the utmost significance in the environmental and socioeconomical matters in recent years. Moreover, as a developmental index, it stands first on an international level. The quantitative and qualitative situation of afforestration of Malayer's forest park with an area of 92 hectares was investigated, using systematic random sampling with intensity of inventory 1.3%, 100 ×150 dimensions and circular sampling plot of 200m2 .This forest park was afforestated with Pseudo acacia, Ash, the tree of Heaven, Cypress and Pine species. In quantitative evaluation, features such as diameter at rest height, the crown diameter, the height of tree and the length of crown and in qualitative evaluation, features such as the shape of the crown, the health of the tree, and the shape of the trunk were measured. In quantitative evaluation, data were analyzed by Duncan and analytic variance tests. The results showed that in soft woods, Pine with average diameter of 15.4 cm and the height of 6.75 m and in hard woods the tree of Heaven with average diameter of 10.97 cm and height of 5 m have the maximum growth. Comparing to Hardwoods, Softwoods are qualitatively in the better condition: Cypress and Pine with 93 percent of freshness are in the superior condition of the health of the crown.

Acquiring up-to-date quantitative and qualitative information about forest stand is necessary for scientific management and planning of forest. Remote sensing by its great capabilities can be very useful. The aim of this research was investigation of the relationship between density (number of trees per hectare) of Beech stands and its spectral signature on satellite data. For this reason 21 plots of one hectare dimension with selective method were used in Kheyrood forest. In the plots, diameters of all trees, which were above 12.5 cm, were measured and recorded.Then coordinant of each plot was recorded and digital map of them was prepared. Geometric correction was performed up to orthorectification level with affine transformation and resampling of nearest neighbour. To produce synthetic bands, Ratio, Principle component analysis and Fusion were used. Digital numbers matching with plots from principal and synthetic bands were extracted and used in regression analysis test. Results showed maximum correlation for density and image with G/R, GRVI, (G㒄) and(G㒄)/( G㒄) were found respectively with correlation coefficient of -74/4%, - 73/5% -53% and -52%. Formulae to predict tree density per hectare using digital number of images were obtained. Results of this study magnifies the hypothesis of possibility of predicting density using satellite images.

In order to consider the effect of sowing date on germination characteristics in seeds of Pinus brutia, a Complete Random block design with four replications and 60 vests per replication was performed and pure seeds of Pinus brutia were planted in two different dates including November 20 and February 1. At the beginning of growth season, germination was recorded every 5 days. Then results of parameters including germination, germination percent, energy, peak value, speed and capacity and survival were calculated in autumn and winter sowing date. The results showed significant effect of sowing date on germination. Suitable sowing date for seeds of Pinus brutia is autumn, which is optimal considering labor force scarcity in winter and decrease in costs.

The purpose of this study is to estimate a collection of important quantitative variables for individuals of single species and to utilize them in planning and management of afforested fields in natural ecosystems. To this effect, pinus teade, a coniferous needle leaf plant species, which has been planted in Syahkal forests for the past twenty years, was selected. The total area of field of study is 3.7 hectare and Random Systematic statistical method has been used for selection of samples. Based on this statistical method 250 tree individuals were selected and important quantitative indicators were measured. This study showed that the mean, variance, standard deviaition, Median, and Modes for pinus teade are 16.6, 12.27, 3.5, 16.25, and 15.82 centimeters, respectively. Calculation of confidence limits with 95% probability showed that about 68% of trees have a diameter of equal to 13-20 centimeters and of This about 95% have a diameter range between 9.6-23.6 centimeters. In addition, study of correlation between height and diameter of the studided trees shows that the degree of correlation is about 65%.

Nowaday, satellite data are the main tools of cycle measurement for collecting information and preparation of maps.Attempt was made ,in addition to the presentation of a method for expansion of the forest in mountainous areas and classification of the forest type, to study the above-mentioned satellite information ability in this research by the use of this type of information. In this study, data from 12 th of June, 2004 related to 38 districts of the country's north forests were used. Initially, data quality and available errors with respect to type and their amount were studied Then, they were used to correct errors resulted from ups and down of Digital Elevation Model (DEM) using 102 point as ground control points (GCP) with the accuracy of less than 0/8 for use in the action of the geometric images match simultaneously. Next, by the use of methods of achieving ratio, filtering and analyzing main elements of new artificial bands of the collecting and classification in the form of one step or multi-step supervision were done by the strategies of the minimum distance of parallel piped, maximum likelihood, mahalanobis distance, spectoral anglemapper, binary encoding, neural net and density slicing. By selction of training areas of the given classes and by the help of the minimum and maximum diagrams and average of these areas for each class in each band, the best channel to enter the classification and achieving the best results were selected. Afterwards, by separation of forest category from non-forest one, action was taken to prepare a map, so that the accuracy of the resulted maps of the classification by the strategies of the parallel piped and minimum distance of mahalanobis, among other algorithms, was more than the others, This suggests that ASTER data, according to the applied method, do not have a relatively good capability to study and examine the forest classification in this mountainous area.

In present research, two species of planted Populus deltoids and Alnus glutinose have been selected in order to measure their longitudinal stress and strain in the north of country. The intended trees of Populus deltoids have been selected from Astane Ashrafiyyeh region in the west of Gilan province and the trees of Alnus glutinosa have been selected from Lahijan region in the forests of Deilaman. Growth stresses were measured by longitudinal residual strain of maturation in the outskirt environment of trees stem and through single hole method that has been recommended. Results indicated that There was a direct relationship between the strain and stresses with the age and diameter of the tree and the types of wood that were mainly reaction woods; meanwhile, other environmental factors such as wind and slope affect strain and stresses in the two species. In the comparison between the above-mentioned species, because of the high sensitivity of Populus deltoids in lower ages to high amounts of stress and strain, and because of the high sensitivity of Alnus glutinose to environmental factors such as major wind and the slope of ground (about 30%), relatively large amounts of stress and strain were seen in these trees. The mentioned condition with regard to longitudinal and strains was definitely observable so that the average longitudinal strains were 0.06 percent in the species of Populus deltoids and 0.05 percent in Alnus glutinos.

Growth stresses are one of the major problems in conversion of trees to timbers especially in hard wood trees. They can cause severe timber degradation such as end split in logs and stems, warp and end checks in lumbers or even difficulties in cutting process like pinch of saw blade. It has been demonstrated that growth stresses are under the control of genetics and the influence of environmental factors. But, the fact that up to which level the impact of environmental factors on various species could result in higher levels of growth stresses is still under investigation due different properties that numerous species show in response to these conditions as well as different reactions in one species or even at one stand. The aim of this study was to focus on the stem size parameters and make a link with the levels of growth stresses in Hornbeam species. In doing so, 11 trees from Iran Northern Forests located close to Nowshahr, were used for the DBH, height, age, pith eccentricity, and longitudinal growth stress measurement. Results showed that by the application of single factor regression analysis to consider only one factor as a result of higher intensity in growth stress indicator (GSI), the obtained correlation could not be significant. But, through a step-wise regression modeling by a multiple factor linear regression analysis, GSI could be predicted as a function of age, height, and DBH up to 84% with a high significant correlation. This reveals that growth stresses are significantly under the influence of stem size specifically on the Hornbeam species as one of the hardwood trees and also shows that the nature of growth stresses are very complex.

In this research, samples of Origanum were collected in areas of Kojour region of northern Iran during the flowering stage on June 2008. The Sampling was conducted in three time intervals: morning, noon and evening. All samples were air-dried in the shade. Extraction carried out by hydro-distillation technique by modified clevenger trap for two different times (2 and 4 hours). Analysis was evaluated by GC and GC-MS apparatus. Based on dry weight of the herb, oil percentage of morning, noon and evening samples were 1.00, 1.11 and 1.01% after 2 hours and 0.92, 0.86 and 0.80% after 4 hours of distillation, respectively. It shows that morning samples have the most essential oil contents. Among 35 identified compounds of the essential oils of this herb, Thymol, γ- Terpinene, 1, 8-Cineole, ß-Cymene and Carvacrol were the major compounds in the first two hours of extraction while after 4 hours of extraction, trans- Caryophyllene, Germacrene D, Bicyclogermacrene and decane were the most important essential oils.

In this study, selected statistical methods (Pearson correlation and Geostatistics) were used to determine the most important water quality parameters and their Spatial variability in different parts of Anzali wetland. After a random sampling of water in 9 different points of wetland and 11 rivers that flow into Anzali Wetland, the most important parameters were measured. Pearson correlation results showed that DO have negative correlation with BOD ,COD, T-N, T-P and turbidity. To use the ordinary Kriging in Spatial variability of parameters, normal distribution of data was first determined using Kolmogorov-Smirnov test and after Semivariogram calculation, circular, spherical, exponential and Gaussian models were fitted to each water quality parameters and Cross-Validation was used for validation. The best model for EC ,pH, COD, DO, BOD, turbidity, T-P and for T-N were exponential and Gaussian. The results revealed a high estimation accuracy for pH, T-N, and T-P. In addition, Kringing application reveals Shijan and Abkenar have the worst and the best water quality, respectively and water quality decreases from west to east part of the wetland.

Khoshkeh Daran forest with an area of 256 hectares is located in a flat region in the east of Tonekabon, and has been named as a national natural monument in 1971. The main types of trees in the park are Alnus glutinosa, which along with Pterocarya fraxinifolia,Parrotia persica, and Ulmus minor form the major trees in the area. In order to obtain more detailed information about the growth characteristics and vegetation struture, floristic studies have been conducted. A total of 149 species from 124 genera and 64 families were determined. The most important families were Rosaceae, Poaceae, Asteraceae and Papilionaceae which also make up the most prevalent species in the forest. The most important life forms were Hemicryptophyte and Phanerophyte, which have been studied by the Raunkiaer method. Also based on chrological studies, using Zohary Method (1980-93), Euro-sib chrotypes and polyregions, Euro-sib.- Medit.-Ir-Tur. have been identified as the most important phytochorion structure in Khoshkeh-Daran forest. In conclusion, the findings from these studies can help us resolve many problems pertaining the management of such reserved lands.