مهندس محمدرضا نجیب زاده

Nowadays, natural resources are exploited for the purpose of economical development in developing countries. Expansion of agricultural lands, supply of charcoal and fuel wood and wood production play an important role in forest degradation which affects biodiversity, soil conservation, the quantity and quality of water and the global climate conducted to the importance of forest conservation and reforestation. Therefore quantitative assessment of forests is required for conservation programs and forest monitoring is defined as a tool for sustainable forest management.Today, remote sensing techniques and satellite images can widely provide functional information in environmental studies. In this work, sentinel-2 satellite images with high spatial, temporal and spectral resolution were applied to determine the area, distribution and density of the Arasbaran forestsas well as other land use classes in the area.

Arasbaran area is located in Qaradagh mountainous region inthe north of East Azerbaijan province between 38°25′ 59 " N- 39°20′ 7.7 " N latitude and 46°09′ 18 " E- 47°16′ 5.3 " E longitude which covers an area of 551211 hectares and the deciduous forests of this area are known as the 11th Biosphere Reserved in Iran. The altitude varies from ca. 256 m tomore than 2000 m. the importance of the area is in having a rich flora (about 1334plant species) and unique vegetation among the vegetation of the country.
For the first time, the Sentinel-2 images with a combination of high spatial and temporal resolution were used to classify the land use of the area.The best band combination was found for bands 2, 3, 6, 12 and NDVI index. Land use classification included dense, semi -dense, sparse and very sparse forests as well as rangeland, agriculture, residential area-bare soil, garden and water was implemented using 9 different algorithms in a pilot area to find the best algorithm. 280 training sample points were collected from all different land use classes in the area.Consequently, supervised classification technique and Maximum Likelihood algorithm with the Kappa coefficient of 0.886 and anoverall accuracy of 89.6% was identified as the best classification method for the Arasbaran area.Accuracy assessment of the final map was done using ground control points and Google earth images with a total accuracy of 95%.Finally creating an error matrix with 880 ground reference test pixels revealed the accuracy indices.

The final land use map of the Arasbaran area based onthe Supervisedclassification technique and Maximum Likelihood algorithm was created.Based on the results, the accuracy assessment of the final map showed that the Kappa coefficient and the overall accuracy of the classified map were 0.88 and 89.8% respectively.The forest distribution and canopy cover density map were extracted from the land use area map. The total area of forests with a canopy cover of more than 5%, obtained 131019 ha consisting of 39% dense forest, 36% semi -dense forest, 17% sparse forest and 8% very sparse forest. In addition, the largest type of land use accounted for rangeland with 270000, forest with 131019, agriculture with 101974, residential area-bare soil with 30028, garden with 15434 and water with 2756 hectares respectively. Based on the error matrix table and correct classified points as well as total ground control points, the highest user’s and producer’s accuracy belonged to the densed forest class as well as the lowest user’s accuracy and lowest producer’s accuracy belonged to garden and agriculture classes respectively.

The results conducted supervised pixel-based image classification based on the Maximum Likelihood algorithms an acceptable method. It can be because of well -distributed training sample points, the high spatial resolution of sentinel-2 images or Environmental heterogeneity of the area. According to the results, dense forests declined(from 56910 to 50628 ha)however semi -dense and sparse forests have increased (from 35280 to 47930 ha)with respect tothe last forest survey project in the Arasbaran area in 2003.In addition, the results revealed an overlap between agriculture and garden as well as rangeland and residential area-bare soil classes because of multi culture of crops and fruit trees together as well as dried or low vegetation cover of rangelands in the area. These results can provide useful information for decision- making and sustainable forest management for reducing forest degradation and it seems to be an important next step to manage these forests based on conservation policies.

In this research, the preference value of rangeland species in Sahand rangelands of East Azarbayjan province was studied for four years (2007-2010). The preference index method was used for this purpose. After determining the amount of production and consumption of each species selected in the grazing season (June, July, August, and September) and calculating the share of each species in the forage production of the region and livestock feed, and calculating the preference index, the data analyzed in split-plot design based on the completely randomized design in SAS software. The results showed that the effect of the year in three species, the effect of the month in four species, and the interaction of year and four species at (p≤0.01) were significant on the preference index. The preference index is a very important factor in determining the preference value of plant species for livestock. The species of Festuca rubra, Tanacetum chiliophyllum, with an average preference index of 1.4 to 1.6 during four-year, has a relative preference and is a relatively benign species and was placed in the palatable class I. Tanacetum chiliophyllum, with the highest average preference index, was ranked first among all herbaceous species. The species of Bromus tomentellus, Festuca ovina, Alopecorus textilis with an average preference index of 0.7 to 1.2 were of moderate preference and were classified as moderate in palatability and classified in the palatability class II.  Astragalus aureus, with an average preference index of about 0.3, had a relative preference, and this species was almost non-chewed and ranked in the palatable class III. Overall, the results of this study showed that the preference value of Festuca rubra and Tanacetum chiliophyllum was more than the other species, and the sheep preferred the forbs, followed by grasses and shrubs for sheep grazing.

It is important to determine the suitability of rangelands for the utilization of medicinal plants. The purpose of this study was to introduce some of the criteria and indicators, influencing the rangelands suitability for medicinal plants exploitation and to investigate the differences between the results of using different approaches of suitability determination. To this end, the suitability of the Arshad Chaman rangeland was evaluated in terms of the utilization of medicinal plants. The results showed that according to the limiting factor method (a common method of determining the suitability of rangelands), 2, 6 and 77 percent of rangelands had respectively good, moderate and low suitability and 15 percent were not suitable for utilization. The mathematical method (using hierarchical analysis process) showed 4, 26, and 45 percent of the rangelands as good, moderate, and low suitability, respectively, and 25 percent as inappropriate for exploitation. The application of the theoretical method (MSMPE) also showed that 39 and 61 percent of the rangelands had respectively good and moderate suitability. In general, it was observed that there were no significant differences between the classes of suitability obtained by the limiting factor and the mathematical methods; however, there was a difference between the classes obtained by the limiting factor and MSMPE methods, and different classes of suitability were obtained for a given area of rangeland in these three methods. Therefore, it is recommended to test the accuracy of the findings of the present study to achieve a practical result in different years in terms of climatic events and other locations with different physical properties. Overall, based on the combined results of different approaches and in terms of physical and environmental constraints, the study area had low suitability for the exploitation of medicinal plants. Therefore, to reduce the livestock pressure on rangelands and increase the diversity of medicinal plants, more attention should be paid to the other aspects of rangeland use such as beekeeping and free tourism.