Study of most element of forest destruction by used the IRS-1C and LANDSAT image in the southern zagros forest (Case study:

ABSTRACT The Zagros forests (west of Iran) have been highly exploited in recent decades by human impacts. Easy access, abundance and variety of valuable forest yields have led to population growth density, creation of new residential areas and deforestation activities. In order to determinate the distribution and rate of deforestation from 1995 to 2006 by using the satellite imagery (IRS-1C and LANDSAT image) and possibility of modeling the changes extent and its relation to physiographic and some human factors by using multiple regression in the Kohkeloeye and Boveirahmad province, Golestan province. Southern Zagros forest, west of Iran. Classification was performed using maximum likelihood classifiers and forest divided two classes (forest and non -forest). Results showed that the maximum likelihood classifiers exhibited the highest results with 96% overall accuracy and 74% kappa coefficient. The results showed that about 462.5 ha from forest areas were deforested in the 12 years. To determination of major element of forest destruction used the multiple regression methods. According to results distance from road and village variables were in contrary of deforestation expanding. Forest destruction was increased with increasing around populated villages and near of this village

The role of coppice oak stand in carbon storage and ‍CO2 uptake (Case study: Khalkhal, Iran)

Regarding to the importance of forest in carbon sequestration, this study attempted to investigate the carbon storage potential and CO2 uptake in a coppice oak stand. An area of 278 ha of Khalkhal forest located in Ardebil province, north of Iran was selected as the study area. After combining slope, aspect and hypsometric maps, 63 land units (polygons) as well as their area were determined. Then 60 sample trees were selected in such a way that all environmental and typological conditions were taken into account. After determining the fresh weight of different parts of trees in the field, their dry weight and biomass was determined after drying in the kiln. The humus was collected and weighted from an area of 400 cm2under canopy of each tree. To determine the organic carbon content of the biomass, ash content was deduced from dry biomass. To determine the amount of stored carbon in soil, samples were collected from 0-10 and 10-30 cm soil depths. The amount of annual sequestrated carbon in biomass and soil was estimated as 1.51 and 0.1 tons per hectare, respectively. The annual carbon dioxide uptake was 5.94 tons per ha

Investigation on satellite data fusion operation effects on accuracy of forest type classification (Case study: Mazandaran province)

The combination of panchromatic band with multispectral data is known as data fusion operation, which increases ground resolution of multispectral data. The results of the application of this method on the accuracy level of forest type classification were investigated. The multispectral data and PAN band from the ETM+ sensors belong to forest district located in "Azarrood" forestry plans in "Savadkooh" were used for the sake of this survey. The bands were controlled according to Radiometric and geometric error separately. Band 1, was omitted because of the existence of radiometric error and its less importance in vegetation cover study. Geometric correction was performed by 22 round control points with DEM, up to orthorectification level, with up precision of least than half pixel. Fusion operation was performed by PC method. The supervised classification was performed with using basic and synthetic bands (ratio, principle Analysis), with maximum likelihood, minimum distance, parallelepiped algorithm. The highest overall accuracy was 34.12% and kappa coefficient 23.15% for separability six vegetation type. The result shows the reduction of data correctness in compare with the result of produced forest type map without fusion. That as the reasons, we can indicated are, selected method type for fusion operation, heterogeneous area. Therefore, the repetition of this operation in another area with using other fusion methods is proposed

Comparison of lead content absorption in different parts of Eldar pine (Pinus eldarica Medw.) in Tehran city

Evaluation of toxic metal concentration in soil and plants are the most important subject according to the health of ecosystem. This study was carried out to investigate on the lead content absorption in different parts (leaf, root and branch) of Eldar pine (Pinus eldarica Medw.) trees in Tehran city. For this aim in polluted sites (Azadi, Bahman and Bazar) and controlled site (Aghdasiyeh), in defferent seasons (January, March, July and September) and in different distance of air pollution measurment station (0, 500m and 1000m), 432 samples from leaves, branches and top root were collected and lead content density in each samples determined by atomic absorption instrument model Varian 220. Result indicated that lead content absorption in root of pine was higher than aerial parts (leaf and branch). Lead absorption in parts of tree in Azadi site was higher than other sites and the lowest content of lead was measured in Aghdasiyeh site. However, the highest lead content in parts of trees was observed in September and the lowest in March. The results also showed that by increasing of distance from air pollution measurment station, lead content absorption in parts of trees decreased

Investigation on the capability of digital data of ETM+ sensor in seperating of forest types (Case study: Lafoor area of Savadkooh)

This study was carried out in order to investigate the capability of digital data of ETM+ sensor in separation of forest types in Gazoo district of Lafoor area in Savadkooh. The bands were controlled according to radiometric and geometric errors, separately. Band 1, was omitted because of the existence of radiometric error and its less importance in vegetation cover study. Geometric correction was performed by 21 ground control points with DEM, up to ortho rectification level with precision of less than half pixel (0.3 pixel). The supervised classification was performed by using basic and synthetic bands to 6 classes, (pure beech type, mixed beech type, mixed hornbeam, road and non covered area, persimmon, mixed broad leaf). Ground truth map prepared through sampling in 24% of whole area. The highest overall accuracy was belong to maximum likelihood classification for 6 classes which was 38.29% and Kappa coefficient was 27.7%. Six vegetation types were merged because of radiometric mixing, therefore classification with 5 classes was performed again. Accuracy assessment of classification results indicated that the highest overall accuracy and Kappa coefficient were 53.22% and 34.71%, respectively. Results showed that the ML classification increases %15 of overall accuracy and %7 in Kappa coefficient. Overall, using ETM+ data is not so appropriate in the studies which the map type is considered as a base map with maximum number of existing type in the area. In order to increase the classification accuracy, using of other classification methods like object-base method and the other information and multitemporal data is suggestible

Relationship between leaf area index and phisiographical and edaphical condition in a Quercus macranthera stand (Case study: Andebil's forest, Khalkhal)

This study attempted to investigate leaf area index in Quercus macranthera coppice stand. A forest of 278 hectares located at the northeast of Khalkhal was selected as the study region. The leaf area index was determined by direct method and by collecting all the leaves from the 60 coppice sprouts and measuring the mean leaf area and crown cover area of each coppice group. To determine the soil properties and its relation to the leaf area index, samples from the depth of 0 - 10 and 10 - 30 cm was selected. Physical (percent of clay, silt and sand) and chemical (amount of nitrogen, phosphorus, potassium, organic carbon and pH) properties of soil samples were determined in the laboratory. As a result, the leaf area index of oak species was 3.33 and the average dry weight of leaf was estimated to be 1864 kg/ha. No statically significant relations were observed between the phisiographical conditions and crown canopy density to the leaf area index. Considering the characteristics of the stand and soil, the aboveground biomass, diameter at breast height, tree height and the soil nitrogen showed the maximal correlation with the leaf area index

Spatial pattern of regeneration gaps in managed and unmanaged stands in natural Beech (Fagus orientalis) forests

The spatial structure of a forest stand plays a key role in its dynamics. It also determines the chance of establishing seedlings and the renewal capacity of the stand. However, this relation between spatial pattern and forest dynamics is two sided and information can refine our understanding of natural processes. Regarding to importance of seedling establishment in forest dynamics, the aim of this study was to investigate on spatial pattern of gaps in managed and unmanaged forests. The study site is located in Kheiroudkenar research forest – Noshahr. For this purpose, two sites in beech stands with similarity in physiographical condition were selected and the position of all gaps in each site was surveyed. Also, some quantitative parameters were recorded in each gap. Then, Ripley's M function was used to obtain the spatial structure of gaps. The null hypothesis is a random distribution of gaps which was tested by using of Monte Carlo technique. The results showed that frequency of gaps in managed area is more than unmanaged area. Regarding to average area of gaps (235 m2 in managed area and 210 m2 in unmanaged area), gaps cover 9% of the study area in managed and 4% in unmanaged stand. It means that silvicultural practices intensity was high and it could not be suitable for develop stand structure. Also, spatial pattern of gaps are regular for both area in 60m and 80m radius, respectively. Based on this trend, spatial structure is regular within each stand and random among them

Impact of management on quantitative and qualitative characteristics of forest in comparison to unmanaged forest (Case study: Golband region)

This study was performed in order to consider the effect of management plans on forest, through comparison between qualitative and quantitative characteristics of managed and unmanaged forests. Compartment No. 149 from Shourab district (52.8 ha) and compartment No. 218 from Jamand district (68.7 ha) were selected as managed and unmanaged forests, respectively and were inventoried using a systematic rectangular grid of 80m×125m by 1000m2 sample plots; diameter at breast height, height and stem quality were measured. Results showed that forest type in managed forest has changed from beech-hornbeam to hornbeam-beech. Respecting to species diversity and quality degrees, managed forest was changed negatively in comparison to unmanaged forest. In managed forest, it's appeared that hornbeam populations have increased and as a result society movement toward climax has been slowed down or even prevented. In managed compartment comparing to unmanaged one, hornbeam lost advantage of density in diameter classes, posterior to beech. Also the result of statistical test showed that difference in stock volume between beech and hornbeam species in two compartments is significant