محمد نقی عادل

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.

The aim of this study was to determine diversity of plant species in Hackberry sites in Taniyan and Rezvanshahr areas in Guilan province. For this aim, circular sampling plots of 0.1 ha were implemented selectively based on presence of the Hackberry trees in study area. In sampling plots, DBH of all trees and number of all shrubs were measured. For wood species regeneration, a sampling plot of 100 m2 was implemented in center of large sampling plots and regeneration counted. Also, for record of herbaceous species, Whittaker nested plot method used that 32 m2 obtained. Values of diversity, evenness and richness were calculated using biodiversity indicators in trees, shrub, regeneration and herbaceous layers. The results showed that Menhinic richness index in tree (1.47) and regeneration (0.91) layers in Rezvanshahr site has more than Taniyan site. Maximum of Shannon-wiener index value in both site was in the tree (2.05) layer and lowest was in shrub (0.27) layer in Rezvanshahr site and in regeneration (1.05) layer in Taniyan site. Shannon-wiener diversity index in tree (2.05) and regeneration (1.56) layers in Rezvanshahr site was more than Taniyan site. Amount of this index in shrub (1.36) and herbaceous (1.2) layers in Taniyan site was more than Rezvanshahr site. Also, Smith and Wilson evenness index in each four layers of tree (0.45), shrub (0.58), regeneration (0.63) and herbaceous (0.54) in the Taniyan site more than Rezvanshahr site. Also, in study areas, species abundance followed in tree layer of the broken stick model and in herbaceous layer of log normal model in Rezvanshahr site and followed of broken stick model in Taniyan site.

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.

The aim of this study was to investigate the relationship between physical and chemical properties of soils with vegetation distribution in Divan-Darre rangeland as one of the most important rangelands in Kurdistan province. For this purpose، a random systematic 150 m × 200 m gird sampling plan was used to establish 90 sampling plots. In each plot، soil factors and percent cover of each plant species were recorded. The minimal area method was utilized to determine the sample size in the herbaceous layer in this study that it was obtained 4m2. Percent cover of each species was estimated base on the Braun-Blanquet criterion. Vegetation classification was done to determine ecological species group using Cluster method. Ward’s method used to calculate the distance amongst clusters، and Euclidean method for distance index was used. The result of clustering analysis was indicated that four ecological species groups were found. Multivariate analysis was performed to detect the relationship between the physiographic، soil factors and the ecological groups. The most important physiographic and soil factors in these communities were belonged to N، K، OC، OM، pH، SP%، soil texture (clay، sand، and silt)، EC، elevation، aspect and slope. Since each plant species has the specific ecological requirements to soil properties and physiographic factors، study of them can be used to improve vegetation restoration.

Riparian forests maintain diverse vegetation structure through the influence of various types، intensities، and frequencies of disturbance promoted by fluvial and geomorphic processes. These fluvial and geomorphic disturbances vary longitudinally from headwater streams to low-gradient alluvial rivers and result in different types of plant communities according to longitudinal location. The aim of this study was to investigate on the floristic composition، life forms and chorology of all plants along Safa-Rud riverside between 350-2400 m a. s. l in Ramsar forest. The final results of the studies on floras showed that 260 plant species belonged to 226 genera and 77 families. The Dicots with 204 taxa were the richest group of flora followed by monocots with 41 taxa، Pteridophytes with 13 taxa and Gymnospermae with 2 taxa. Dominant life forms include Hemicryptophyte (38. 37 percent)، Geophytes (23. 55 percent)، followed by phanerophytes (18. 6 percent). From the chorological point of view، the largest proportion of the flora belongs to the Euro-Siberian elements (23. 25 percent) followed by Pluriregional elements (21. 7 percent)، Euro-Sibirian/ Irano-Turanian (18. 6 percent) and Euro-Sibirian/ Irano-Turanian/ Mediterranean (15. 11 percent). Riparian Forest are severely degraded especially by human factors، thus a careful planning is needed to protect them.

The aim of this study was to evaluate herbaceous species diversity in a pure and an untouched beech forest. For this purpose, 170 ha of Roudbar forest of Guilan province were investigated. With using biological indices, numerical values of species diversity, richness and evenness calculated and the results were compared to similar studies. Results showed that values of indices obtained are less than other studies. Causes of this problem are a lot of litter depth, high canopy percentage, being the study area at high altitudes and the lack utilizing in the region due to lack of road networks. The evenness amount had more effective than richness in diversity amount. Abundance distribution curve of species followed log normal model.The most cover percentage was related to Bromus benekenii species that is an exotic species and is considered a serious threat to biodiversity in the region.

The aim of this study was to investigate some of the most important ecological features of the Hackberry trees in Guilan forests. Data was collected using 25 and 20 plots (Rezvanshahr and Tanean sites, respectively) based on the presence and absence of Hackberry. The inventory was selective sampling method. A circular sample plot with an area of ​​1000 m2 was used. Some geographical and ecological characteristics of each sample plot and some quantitative factors of the Hackberry trees were recorded. Soil samples were collected from the center of all plots at the depth of 0-30 cm. The results revealed that the average diameter and height of Hackberry trees in the south aspect of Tanean was more than Rezvanshahr site, and significant differences were observed between two sites. But there was no significant difference in other aspects. Highest percentage presence of Hackberry trees was on slope ranges from 31% to 50%. In addition, the results showed that the values of nitrogen, organic carbon and organic matter were positively correlated with Hackberry, and Cation Exchange Capacity (CEC) and P were negatively correlated with them.

Many of physical and chemical properties of soil change under the influence of fire. Fire can affect the soil elements and forest soil. This study reviews effects of fire on soil physical and chemical properties in Saravan forest of Guilan Province of Iran. Three 50-hectares sites were selected with similar physiographic conditions and vegetation cover (Taeda pine plantation). In a 10-year period (1379-1389) Fire had occurred seven times in Kashal Varzal area and three rimes in Mushangah area. Kacha area was considered as a control area that had no fire. Fire was recorded based on forms of Department of Natural Resources in Guilan as fire surface. Data measured using systematic sampling with dimensions network 100*200 meter. 25 plots in each area were determined. In each plot, three samples of soil taken from depth of 0-30 cm and one combined sample transferred to the laboratory. Results research showed the fire had effect significantly on nitrogen, acidity, phosphor, potassium, organic carbon, sand, silt and moisture content saturated and no effect significant on the electrical conductivity, CO2 and clay has. Also fire increases the acidity, phosphor, potassium, sand and reduces organic carbon, nitrogen, silt, clay, CO2 and saturated moisture content.

The aim of this study was to investigate Autecology of Montpellier maple sub. Species in Fars Province Forest. The results showed that Montpellier maple is distributed from an altitude of 1900 m up to 2750 m. in Firouzabad area, Montpellier maple more is found in northern and eastern slopes. in Sepidan area, this sub. species is found in southern slopes and related direction of the south. Number of seeding crop trees of Montpellier maple is higher in the upper elevations.Results from CCA analysis revealed that plots which have a positive correlation with the first and second axis are located at area with higher water saturation, EC, Caco3 and clay and plots which have a negative correlation with the second axis are located at areas with lower water saturation, EC and clay.

The study area with 170 hectares is located in the north of Rudbar and between 1010-1560 m a.s.l. There is not any harvesting in the study area due to a lack of a road network. This research has been carried out to identify the floristic composition, life forms and chorology of all plants in this area. The final results of the studies on floras showed that 47 plant species belonged to 46 genera and 37 families. The dicots with 34 taxa were the richest group of flora followed by monocots with 7 taxa, and Pteridophytes with 6 taxa. Dominant life forms include geophytes (49%), followed by phanerophytes (23.4%). From the chorological point of view, the largest proportion of the flora belongs to the Euro-Siberian elements (42.6%) followed by Pluriregional elements (14.9%), Euro-Sibirian/ Mediterranean/ Irano-Turanian and Euro-Sibirian/ Mediterranean (10.6%).

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.