Log extraction with draught animals continues to be a suitable choice in many areas, even in industrialized countries. As compared with ground-skidding equipment, the use of animals has been shown to reduce soil disturbance, soil compaction and damage to residual trees significantly. This research was carried out in compartment No. 220 & 225 of Namkhaneh district, in Kheyrud Forest. In order to evaluate damage to stand and regeneration following mule hauling, before and after operations, hundred percentage inventory of regeneration in mule trails were conducted. Compacted soil sampling in mule trails was measured. Results of this study showed that following traditional wood hauling by mule, twenty two percent of regeneration in mule trails was damaged and no damage was observed to trees by this wood hauling method. As a whole, 4.3% of total area were disturbed and compacted by applying tradition hauling. The ANOVA effect f mule passes an slope, and soil bulk density showed that mule passes and slopes, as well as, their interaction effect had no significant effect on soil bulk density (P<0.05). Also paired sample t-test showed that traditional hauling has no significant effect on soil bulk density in trails befor and after mule hauling statistically.

Due to the lack of comprehensive policies for the Hyrcanian Forests of Iran, formulating policies which encompass sustainable approach to Forest management is essential. Therefore, in this research, we develop basic policymaking categories for the Hyrcanian Forests of Iran. In order to get the objective, 47 national and international documents, including conventions, statements, policy documents, acts, programs, and reports related to the international dialogues, summits, conventions and forums and national vision, sectorial policy documents, international approved conventions, concerning Forest and Forestry issues were investigated by using of qualitative content analysis. Finally, 124 categories including 61 opportunities, 23 threats, 27 strengths and 13 weaknesses were extracted. Most of the opportunities come from international dialogues, while major threats are non Forest sectorial legislations that challenge the mission of the Forest management organization. The strengths are legal authority, resources and infrastructure, and the weaknesses are mainly related to the organizational structure and available financial facilities. According to the opinions of 78 experts of various stakeholder groups, all mentioned categories scored "partly high" to "high" in a 10 points scale. According to the results, Forest, Rangeland, and Watershed Organization efforts to use the strengths and opportunities to cover the weaknesses and threats were insufficient and more research suggested elaborating the situation.

Managing Hyrcanian Forests in Iran requires a well-designed and constructed network of roads that are appropriately distributed and aligned with the silviculture method. These roads enable access to protection, support, and tourism activities, as well as facilitate the execution of all necessary measures. Around 10,000 kilometers of roads have been built in Iranian Forestry projects. Constructing roads in Forests has both positive and negative consequences on nature and its natural functioning, including impacts on biodiversity, grass and plant cover, and physical and chemical soil properties. The design and construction of these structures should adhere to the principles and technical-engineering standards of Forestry to minimize adverse reactions. To ensure compliance with road construction technical instructions (Publications 131 and 148 of the technical deputy in the Management and Planning Organization of Iran), it is recommended that the Natural Resources and Watershed Management Organization of Iran supervise their implementation in all Forest areas, alongside Forestry plans. Furthermore, the organization should increase its direct supervision of the country's entire natural resource field to improve project outcomes.

In this study, the site form index which is the most reliable criterion for evaluation of Forest site productivity in uneven-aged and mixed stands was used. For this purpose, random-systematic sampling method was used to locate 105 0.1 ha circular sample plots in beech dominated Forests in Tarbiat Modares University research Forest. The height and diameter ofFagus orientalis Lipsky trees within each sample plot was recorded along with elevation, azimuth and slope of the ground. Also, at the center of plot, soil samples from first layer (0-10 cm) were taken for analyzing several soil variables. Evaluation of Forest site productivity by using classification and regression tree algorithm showed that after pruning the full tree, phosphorus, TRASP, clay and bulk density are effective variables, in order of relative importance, on site form and 62% variations in productivity can be explained by these variables. Using generalized linear model and evaluation criteria such as AIC, RMSE, R2 and adjusted R2, the performance of CART model was assessed. The results showed though CART techniques and the generalized linear model justify the same variability in Forest productivity but decision tree technique in terms of AIC and BIC criteria is better than the GLM and as well as this technique is easier to interpret.

Tree felling includes all activities undertaken to fell standing trees and prepare them for extraction. This study was conducted in Gorazbon district in the Hyrcanian Forest. The objectives of the study were to discover the special characteristics in the time consumption of manual tree felling, productivity and costs, and develop regression model of tree felling in selection conditions. The continuous time study was conducted with professional operators for chain-saw felling and the cycles were broken down into time elements. Different variables were measured such as time consumption, inter-tree distance, tree species, tree volume, and tree diameter. Rest and meal time of working crew was the most time-consuming element in felling, followed by under-cut and walk-to-tree times. The operational delay was the most time-consuming delay time. The results showed that time consumption for under-cut and backcut was increased with increasing diameter. Labor costs accounted for 44 % of the hourly cost while only 2 % was related to machine cost. A significant linear relationship was found between cycle time and diameter. Productivity of chainsaw felling was increased related to tree DBH as a power function. The cost of chainsaw felling with and without delay time were USD 3.03 and 2.7 per cubic meters, respectively. The cost of felling was increased as simple exponential function when DBH of harvested tree was decreased. However, the unit felling cost for chainsaw operation decreased as size of tree increased. Total felling cycle time without delay averaged 4.1 minutes and with delay time were averaged 4.65 minutes.

In this study, the capability of single-polarized TanDEM-X data was assessed for estimating the Hyrcanian Forest height. Two approaches of Sinc interferometric coherence model based on Random Volume over Ground (RVoG) and differential interferometry utilizing airborne LiDAR-derived DTM were compared. The study was conducted in part of Dr. Bahram Nia’s Forest management plan (Shast-Kalateh). 308 circular sample plots with an area of 0.1 ha were used in evaluating the accuracy of predicted Forest height using two different approaches. For this reason, Lorey’s mean tree height weighted by basal area was calculated. The interferometric coherency was involved in the Sinc function for inverting Forest height. We also removed topography from the SAR phase calibrated with LiDAR-derived DTM on open areas for estimating Forest height based on differential interferometry. After terrain correction, the average predicted canopy height was extracted for each plot. Our results showed higher accuracy of differential interferometry than the Sinc model in Forest height estimation when compared with ground reference data (RMSE=2.86 m and rRMSE=12.28%). Although, the accuracy of estimated Forest height by the Sinc model was comparable with RMSE=3.41 m and rRMSE=14.46%. We found TanDEM-X data and coherence-based models a relatively promising approach in the Hyrcanian Forest even though only 15% of Lorey’s men height change was explained by the Sinc model. Hence, further studies are needed to figure out the effects of species, slope, and image aquisition features on the results.

Introduction: Diverse gap sizes have formed in temperate Hyrcanian Forests as a result of different silvicultural operations. Understanding the consequences of these practices on Forest stand dynamics can help in deciding the choice of silvicultural methods. Therefore, the purpose of this study was to investigate the effect of canopy gaps on the carbon stock of beech trees and compare it with the adjacent stand and also the interaction between tree attributes and their carbon stock.Material and methods: The created gaps from single-tree cutting were classified in three classes of small, medium and large area with five replicates for each. Trees were also identified in the adjacent Forest to each gap at a distance of 20 m from four directions of them. Tree height, DBH, surface area, volume, length, diameter of crown and carbon stock of trees were measured. One-way analysis of variance was used to compare the average carbon stock index of beech trees in canopy gaps and in different situations as well as for large diameter trees. Independent t-test was applied to compare the average carbon storage in the height classes of the trees and also between the adjacent Forest stands with the canopy edges. Pearson correlation coefficient was used to determine the correlation between the index of carbon stock amount with some structural features of beech trees in the edge of the canopy gaps and the adjacent Forest stand.Results and discussion: The findings revealed that the carbon stock of beech trees along the gaps' edges differed significantly (p≤0.05). No significant difference in carbon stock was observed for beech trees among different directions at the edge of the gaps (p≤0.05). There was no significant difference between the mean value carbon storage of trees at the edge of the gaps and the adjacent Forest (p≤0.05). The highest mean of carbon was observed in the large-sized trees (3725.28 ± 584.49) at the large gaps. The results of correlation showed that with increasing DBH, height, length and diameter of the crown and the volume of the crown, the amount of carbon storage of trees increased at the edge of the gaps and also in the adjacent Forest (p≤0.01). Conclusion: Findings indicate the effect of canopy gap area resulting from the implementation of single-tree selection method in beech Forest. The correlation between the structural characteristics of beech trees such as DBH, height and crown area with carbon stock shows that when applying silvicultural methods (tending and logging) in Hyrcanian Forests, structural characteristics Beech trees, especially the abundance of large-sized trees, should be considered with more carbon stocks in them.