فهرست مطالب mohammad naghi adel

Ungulate grazing is the most common land use in the world and one of the most impacting disturbances on species composition together with habitat destruction. The aim of this study was to study effect of livestock and forest dwellers exclusion on regeneration in Fouman forest in Guilan province.

For this purpose, 200 plots (100 plots in the grazed and 100 plots in the non-grazed area) were sampled by a randomized-systematic method with 100 m2 circular plots in the 100×200 meters grid. In each sample plot, regeneration density and quality condition were recorded. Using questionnaires completed by 100 farmers, forest dwellers status was also assessed.

The results showed that there were significant differences between the two areas in terms of natural regeneration, so that regeneration density was more in the non-grazed region than grazed region. Regeneration quality was better in the non- grazed region than grazed region. The plan failed to properly provide the needs of forest dwellers.

 Discussion and Conclusion:

These results indicate that livestock exclusion have positive effects on Fouman forests and natural resource managers can execute and manage this plan in other Iranian north forests with protect the rights of forest dwellers.

The aim of this study was to study effect of fire on vegetation and natural regeneration in Shanderman forests, Guilan province 7 years after burning. For this purpose, two burned and unburned areas were selected. Within each of the study areas, we used a random systematic 150 m × 150 m sampling grid to locate 40 circular plots of 1000 m2 for tree and shrub species (20 plots in burned area and 20 plot in control area). In each plot, density and DBH of tree species and density of shrub species were measured. Regeneration density was studied by 100m2 plots. Regeneration was studied in three classes as height < 1.3 m, DBH < 2.5 cm, and 2.5 cm < DBH < 7.5 cm. The results showed that density, the DBH and basal area of tree species and density of shrub species significantly deceased after burning. Also, density of regeneration significantly increased after burning. In tree layer, density of Quercus castaneifolia, Carpinus betulus, Zelkova carpinifolia and Parrotia persica significantly increased after burning. In shrub layer, density of Prunus divaricate, Mespilus germanica, Crataegus microphylla and Ruscus hyrcanus significantly decreased after burning. Forest structure was uneven-aged with a reverse J distribution in each two areas. Composition and pattern of dominance didn’t changed in tree, shrub and regeneration layers.

One of the main destruction factors in north forests is grazedby animals that destroys plant species. Hence, evaluation of livestock exit planning has been done at series 2 from Kazemrood area in Mazandaran province. In this paper, density of the regeneration was measured in degraded and protected areas in three height class less than 0.5 m, 0.5 m to 1.3 m and more than 1.3 m and three distance of sampling center 10 m, 20m and 30 m and in four main direction for inner comparison. Results of this study showed that in more distances, the regeneration is increased; also, density in class of more than 1.3 m and western direction had higher density and southern direction had minimum density. The comparison of the regeneration within two areas in three height classes revealed that there are significant differences between them. This means that the livestock emersion planning has been increased density of regeneration. Institutions and organizations are required legally carry out their duties and be directed and controlled through a coordinating headquarters.

We modeled the distribution of oriental beech (FagusorientalisLipsky) stands to determine optimum ecological amplitude range along riparian forests of RamsarSafaroud riverside in Mazandaran province. Data were collected on transects which were perpendicular to the water flow on both river sides. Each transect was 200 m in length, with a 200 m distance between transects. On each transect five 400 m2 quadrats were laid in 50 m intervals. At each sampling location the number of beech individuals with a diameter at breast height (DBH) > 7.5 cm were recorded. In addition three soil samples per plot were taken from the upper 30 cm depth. Totally 44 transects and 220 quadrats were sampled. An extended HOF model implemented in eHOF package in R was applied to assess the response of beech to soil variables, and the corrected Akaike's information criterion (AICc) was used for model selection based on models associated with the lowest AICc values. The results showed that only 27.5% of the models obtained a symmetric normal response curve (model IV), whereas 72.5% of models showed linear and asymmetric (i.e. I to V) curves. However, the VI and VII models were observed in none of the results. We assessed the HOF models to be of high potentials to be further employed in similarly-structured riparian forests.

Forest soil is one of the main factors in forest ecosystem that with other ecological components determines vegetation distribution pattern. Natural areas such as forests have been severely harvest for various reasons in the past years which it has been made soil fertility reduction and production discontinuity. The aim of this investigation was to evaluate the physical and chemical properties of soils in Alder (Alnus subcordata) plantation in Tonekabon forests/North of Iran. For this purpose, at first, forested areas by pure stands of alder were identified. DBH and height of alder trees and their regeneration in each plot was measured. After gathering litter from the soil surface, soil samples were taken from 0-10 and 10-20 cm depths. The soil samples were transferred to laboratory and some important soil properties were identified. The results showed that the moisture in east aspect is more than west aspect. Also, there was a positive correlation between diameter at breast height, height and regeneration with moisture, Nitrogen, Phosphorus and organic matter and a negative correlation with clay, sand, electrical conductivity, pH and neutral material. Alder species can be used as a native species for plantation in similar soil conditions that it is economically and environmentally appropriate for northern forests.

Spatial pattern of trees is an important characteristic of plant communities. Generating hypotheses relating to the structure of ecological communities is the aim of spatial pattern recognition. Stands spatial patterns are measured and mapped by measuring tree locations in the stand and entering each coordinates into analytical frameworks. The spatial pattern of plant populations observed at any point in time is the product of many processes in the past such as seed dispersal, growth, mortality, soil topography, microclimate, or disturbances. The aim of this study is to investigate on spatial pattern of three species Oak (Quercus. libani, Q. brantii and Q. infectoria) in Chenare forest at Marivan city in Kurdistan province. For this purpose, T-square distance sampling method was used. A grid of 100 m×100 m was applied and then 30 sample plots were established. The grid intersections were applied as the center of sample plots and the beginning of distance sampling techniques. Hopkins, T-square and Johnson and Zimmer indices were used to analyze the spatial pattern. All of the indicators showed a random pattern for Oak species. Such spatial information allows to natural resource managers to make better-informed decisions and increase the potential for enhanced natural resource utilization.