نشریه علوم و فنون منابع طبیعی
سال هشتم شماره 1 (بهار 1392)

Land use classification using remotely sensed images is one of the most common applications in remote sensing, and many algorithms have been developed and applied for this purpose in the literature. The Objective of this research is to assess the ability of three algorithms, Support Vector Machine (SVM), Classification Tree (DT) and Fuzzy Artmap (FA) for forest land mapping in Northern forests of Ilam province using LissIII dataset of the year 2007. These algorithms are a group of supervised classification algorithms thathave been recently used in remote sensing. Geometric and radiometric corrections were performed on LissIII dataset. Then, through field surveys, the land cover classes were defined and training areas were selected. The best spectral bands were selected using class signatures and the transformed divergence severability index. Supervised classification of classes was accomplished using SVM, DT and FA classifiers. The results were assessed using sample ground truth map through systematic networks of 550 meter distances. The results showed that forest lands were more easily separated from the other land cover classes. While comparing the overall accuracy and kappa coefficient for the three classifiers, results showed that the Support Vector Machine classifier exhibited the highest overall accuracy (94%) and kappa coefficient (91%).

Fire is one of the most important factor of alteration in the process of stability in land ecosystems, especially forest. With even vainest alterations in the structure of forest, condition of the environment changes and micro species in flora of forest like lichens, mosses, mushrooms, etc. Show the highest sensitivity compared with these disturbances. The normal fires that occurred in Kodir Sar forest in 2010 burnt over three hectares of the district "Pymud". Before 2009 fire, a study was conducted on crustose lichens using 60*40 cm quadrates on trees. Then the position of each tree sampled by random-systematic method and registered by GPS was located. Again after 2009 fire, the changes continued. The results showed that the crustose lichens species decyeased from 40.54% to 12.71%, the fruticose lichens from 27.8% to 7.2% and foliose lichens from 20.14% to 2%. As it is observed in the numbers that were mentioned, we can conclude that the percentage of coverage in general has decreased. But the study on the composition of species showed that four kinds have been added to lichens family that include a kind of Lobaria polmunaria Hoffm from foliose lichens, Evernia prunaste kinds and Usnea longissima (L.) from fruticos lichens and Lecanora argentata(Ach) from crustose lichens after the fire.

The study of pure and mixed stands of canary oak and persian oak was conducted in the second series of Lymakdh in Ramsar. sample collection and study of the ecological factors; the seasons, spring, summer and autumn of the years 2009 and 2010 was conducted and the scientific name of the species, life forms and chorology were recorded using the available resources. 186 species have been identified of 6 Pteridophytes families, 2 families from gymnosperms and 52 families of angiosperms (8 families from a Dicotyledone and 44 families of monocotyledon). The maximum number of species was related to the families of Asteraceae, Papilionaceae, Lamiaceae, Orchidaceae and Poaceae. Raunkiaer’s classification shows that there are Hemicryptophytes 49%, Cryptophytes, 20%, Phanerophytes 19%, and 8% Therophytes, 3% Chamaephytes and 1% Epiphytic species in the region. Chorology study of the area showed the highest value in Europe-Siberia zone (the Caspian), with 41% coverage. The study of the list of endangered species showed, One endangered species, 5 Vulnerable species and 20 species in the region with lower risk. Lilium ledebourii Boiss as a rare species with a relatively wide distribution in different parts of the region was reported for the first time in the oak forest in the north of the country.

dry and tough conditions prevailing over Iran's ecosystems and scarcity of native and compatible species in these regions, shows the importance and value of strong and succulent plants clearer to us. Christ-thorn trees belong to one of these types of plants. Due to this importance, this research investigates site condition of the species Christ-thorn. Since the study area is a plain, sample plots were randomly selected (37 sample plots). A surface area of 64.5 hectares and circular areas of 1200 square meters were chosen. Study variables include the tree's quantitative characteristic (Diameter at breast height, Total height, Crown diameter, and Crown depth) and qualitative parameters (tree's origin, crown's form and their out-branching (ramification)) and some soil factors. Results of soil conditions in the study area showed that the sites were loam soils and electrical conductivity between 0.1-1.8 milli mouse/cm, pH is between 7.5-8 and 30 percent of the amount of lim. This forest is coppice form and all of trees bases have a symmetric crown form, and it has many out-branching state with origin of coppice trees. The average number of hectares in area is 68.5, the tree's average height in the site is 4.23m, and mean diameter breast height is equal to 14.63cm. According to the results obtained in this habitat, it can be acknowledged that the species can survive in suitable habitat conditions.

This study was designed to investigate the ecological conditions of the Northern Forest Region, the collection of kelardasht, conducted in order to prepare the ground first map, 4 homogeneous Per unit 3 replications were chosen. The unit then proceeded to include Marbrday quantitative characteristics such as diameter, height, trunk height, trunk and crown and qualitative characteristics such as health, happiness crown, crown asymmetry were also dug to determine soil conditions in each unit. A sample of the soil surface horizons, was sent to the laboratory for analysis And finally the data using spss software and Pc.Ordwin was analyzed. Results showed that the increase in the number of hectares Breasts Diameter Avery gradient increases initially and then decreases, with increasing altitude, the mean diameter will enhance But the average tree height above sea level has an inverse relation turning to the north side of west. Avery species decreases per hectare, while the average diameter and average basal area of trees increases.

In recent decades, plantation projects have increasingly developed in their importance in regard to environmental financial and social aspects which are introduced as a development index and main infrastructural activity internationally. one of the critical items is the selection of best species for plantation. This research based on the selection of best species for restoration and development of Sisangan forest park by Analytic Hierarchy Process. The park has an area of 591.65 ha that is in elevation of 26-125 m. In this study the criteria parametrs consist of soil conservation, resistance to pollution, wood production, resistance to biologic factors, resistance to anthropogenic factors,secondary production, resistance to flooding, soil fertility, and landscape. The species consist of oak, alder, bath tree, hornbeam, ash, elm, Caucasian walnut,populus, and maple. Then special sheets prepared for data analysis, were given to eight forestation experts. First the, criteria were compared with experts opinions. Results showed that the soil criteria had the highest score and industrial factors had the lowest score. finally the species such as maple, oak and ash were the best species for restoration and development of Sisangan forest park, respectively.

Wood extractive is a nonconstructional material which its effects on physicalcharacteristics have been proved. So it is assumed that it has some effect on wood preservative fixation. In order to understand this phenomenon, the fixation of “acid copper chromate“(ACC) in Alder wood blocks (Alnus subcordata) have been investigated in three status: Control (with extractive), pre-extracted with hot water and pre-extracted with ethanol acetone in 6 different times (0, 192, 384, 576 and 768 hours). The fixation processes in wood blocks have been observed by analytical instruments (Atomic absorption and UV-Vis spectroscopy) and the results were compared with another leaching of woody blocks (vacuum desiccator). The results showed that the water soluble extractive of hardwoods which are predominately tannins, mono and di and oligo-saccharides have positive effect on ACC fixation and removing of extractives increases the fixation of ACC in woody blocks and leaching of ACC specially copper (Cu) in Alder woods. Meanwhile, the fixation occurs at early stages before 192 hours.

In this Study, the effect of profile density on physical and mechanical properties of medium density fiberboard was investigated. Panels from Pars Neopan, Yieldiz, Merbook and Vihova were selected and Samples of panels for physical properties including water absorption and thickness swelling for 2 and 24 hours and mechanical properties containing flexural properties, internal bond and nail strength in surface and edge were cut. Samples were prepared according to DIN-68763 and profile density was based on gradual layering. The results showed when differences between density of surface and core layer increased, water absorption and thickness swelling decreased, but, MOR and MOE increased. High level of surface nail strength was identified in samples with high density in surface layer. But, the effect of profile density on edge nail strength wasnot meaningfully identified. In addition, the effect of profile density on internal bond wasn’t meaningfully identified, but, the effect of density of samples on internal bond was identified.

The present study was carried to investigate annual ring width, physical and biometry properties of natural and plantation of alder wood. For this purpose six trees of natural and planted alder trees were selected from Zirab-Savadkouh city of Mazandaran province. A log of -15 cm thickness was taken at breast height from each tree for biometry, physical propeties and annual ring width. Binocular system was used to determine annual ring width along radial direction from pith to the bark. Three samples were prepared along radial position from the pith to the bark to examine physical and biometry properties, then wood data were analysed by SPSS software. Analysis of variance (ANOVA) indicated that there are significant differences between natural and plantation alder tree in fiber length and slenderness ratio. The plantation condition did not show significant difference regarding the annual ring width, oven-dry density, basic density, volumetric shrinkage, volumetric swelling, fiber diameter, cell wall thickness, Runkel ratio and flexibility coefficient. The amount of fiber length and slenderness ratio in plantation of alder tree was higher compared to natural alder trees. Positive relationship was found between wood density and shrinkage in both species, while this relationship in natural alder tree was about 50% higher than plantation of alder forest.

Juniperus excelsa can survive in difficult conditions such as topography and soil properties and is a suitable species for soil conservation in these conditions. Recognizing the properties of this species habitat is useful for applying them for soil conservation in the same conditions. Since dispersion and density of Juniperus excelsa is more affected by soil characteristic than climatic conditions and elevation, characteristics of Juniperus excelsa habitat are studied in relation to land and soil characteristics. Results showed that Juniperus excelsa habitat are often mountain and hill land types that have sharp slope andtheir slope ranges is 55-90%. Soil types of these habitats are Lithic xerorthent and Lithic xeropsamment that are shallow (Max. Depth: 30cm) and their texture is sandy clay loam to sandy loam. It s pH is 7.32-8.3, so it indicates that habitats are alkaline. Ec is 0.35-2.05 ds/m and %O.C is 0.12-2.85. Results showed that Juniperus excelsa density has more correlation with pH than other chemical and physical properties and this relationship with clay is the second. Correlation between Juniperus excelsa density and other soil properties, specially %O.C, is very low (<0.2).