Felling as the initiation of harvesting chain-work is the first step for preparing trees to market consumption which has severe effect on the subsequent work stages. The aim of this research is to assess the PRODUCTIVITY of manual felling and costs of felling team as well as recognizing their effective factors. In this evaluation after identifying work elements of one felling turn, 72 felling turns were time studied. Furthermore independent variables such as tree diameter at cutting stump height, distance between trees, longitudinal and latitudinal slopes were time studied in each turn. Felling time regression model is a function of independent variables such as tree diameter and distance between trees. Amount of production including delay time and without delay time were 63.48 and 83.19 m3 per hour, respectively. The cost determination model which recommended by FORESTs, Rangelands and Watershed Organization project work agenda was used to determine felling costs. Therefore, felling costs with delay time and without delay time were 4017 Rials per m3 (26872 Rials per tree) and 3065 Rials per m3 (20516 Rial per tree), respectively. The under cut and back cut time and technical delays formed the greatest felling element time of chain saw felling. Examination of the variation effect of the variables on time due to the variation of felling cost showed that increasing in each of the variables causes an increase in time and therefore increases felling costs.

Water is the main factor in FOREST production and rain and snow are the most important sources of FOREST water supply. But always a percentage of rainfall is lost and comes out of the FOREST surface water cycle This article reviews the concept of Interception in the FOREST and the impact of its components on the water balance of watersheds Interception of trees plays an important role in determining the amount of rainfall reaching the FOREST floor and therefore is an important part of the water level in FOREST ecosystems. The part of rainfall that does not reach the soil of FOREST ecosystems is divided into two parts: loss from the surface of tree canopy and evaporation from the surface of debris in the FOREST floor. The amount of rainfall that is removed from the FOREST cover by rainfall is an important part of the amount of evaporation in FOREST ecosystems and has a great impact on the water balance in FOREST areas as well as on the hydrological cycle and food cycle in terrestrial ecosystems. If you know the amount of rainfall in areas with dry season during the growing season, if the amount of rainfall is high, according to the water needs of the mass, by thinning operations, to establish revitalization and also to meet the water needs of species The plant helped effectively. A large share of summer rainfall in the FOREST in the form of Interception is out of reach of the FOREST massif, Therefore, it is necessary to know the amount of Interception, especially to evaluate and measure evapotranspiration in FOREST ecosystems and therefore for the proper management of FOREST watersheds.

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.

Estimation and mapping of FOREST resources is a prerequisite for sustainable FOREST management. Site PRODUCTIVITY is a key indicator of FOREST ecosystem services like wood production, carbon sequestration, etc. It allows FORESTers to forecast growth and production and hence select the most suitable tree species for a site. Due to the extent of Hyrcanian FORESTs and mountainous areas in these FORESTs that are sometimes difficult to access, it seems necessary to find suitable methods for mapping the quantitative parameters in these FORESTs. In this study, site form index which is the most reliable criterion for evaluating the site PRODUCTIVITY of mixed and uneven stands was used. This study aims at mapping beech FOREST site PRODUCTIVITY by using ordinary kriging and inverse distance weighted in research FOREST of Tarbiat Modares University. For this purpose, 123 0.1 ha circular sample plots were laid out in beech dominated stands. The height and diameter of beech trees with DBH³7.5 cm within each plot was recorded. The cross validation results showed that by using criteria such as mean error (OK=-0.036, IDW=-0.192), mean absolute error (OK=1.598, IDW=1.749), root mean square error (OK=2.053, IDW=2.223), relative mean error (OK=0.104, IDW=0.553) and relative root mean square error (OK=5.906, IDW=6.393), Kriging had significant advantage over IDW method and showed high estimation accuracy. Therefore, the methods can be applied to similar uneven-aged beech stands in the north of Iran.

According to the results of the current research, a new approach in application of dendrochronology, using broadleaved tree rings, as main element of PRODUCTIVITY, to evaluate FOREST ecosystem PRODUCTIVITY, has been introduced. In this investigation, tree ring widths of sample cores which have been taken by borer from various species at different elevations, have been analyzed to evaluate their PRODUCTIVITY and possible competitions between species. Ecological application of dendrochronology is main aspect of this study. Results provided in this research, are part of a wide range of dendrochronology study which have been taken during more than six years (started in 2006) to consider climate change impacts on Hyrcanian FOREST ecosystems. Target species in this study are beech tree (Fagus orientalis Lipsky), oak (Quercus castanaefolia C. A. Mey.), hornbeam (Carpinus betulus L.), alder (Alnus subcordata), and maple (Acer velutinum), which have been selected in Galugah FOREST district in Mazandaran province. After visiting the FOREST site and considering the adapting maps, sample cores were collected along a transect line (profile) at three elevation levels, namely 350, 800, and 1380 meters above sea level. Target trees were more or less at same ages. In the study region, during the last 54 years, precipitation trend shows a decrease by 372 mm and temperature trend shows an increase by 0.59oC. Variability in different species responses to inner (competition between species) and outer elements (environmental and climatic changes), at various elevations are highly dependent on species’ nature. Tree ring widths of Fagus orientalis Lipsky in low elevation during last 55 years has decreased, but tree ring widths of this species in medium elevation in the same period has increased. Tree ring widths of beech tree in high elevation have not changed significantly.

The limitation of the resources in economy can be considered as one of the main reasons behind the attentions to the PRODUCTIVITY in all of the areas of management, particularly that of seed collecting. The purpose of the present research is evaluating the performance of the seed-collecting groups in the jungles of the north of Iran. Data was collected from 89 questionnaires which analyzed the seeds of deciduous and coniferous trees. From among the 9 seed-collecting groups, the highest PRODUCTIVITY rates were respectively for Mazandaran Wood and Paper Company, Pylambara nursery, and Katoul Yew Wood Industry Company with 7.5, 6.25, and 5.71 units per labor-hour. From among the remaining groups, Farim nursery had the lowest rate of PRODUCTIVITY with 1.76 units per labor-hour. Analyzing the amount of the collected species of seeds indicated that only in Noshahr Contracting Company the PRODUCTIVITY of labor force was beyond the standard level and the rest were below the standard. Acer capadosicum collected in Noshahr and Najarpoor Contracting Companies was beyond the standard level. The amount of the collected oak was higher than the standard level in five contracting companies and nurseries including Noshahr, Mazandaran Wood and Paper Company, Katoul New Wood Industry Company, Safrabasteh nursery, and Najarpoor Company. Alder species collected in Farim Wood Company, Katoul New Wood Industry Company, and Neka Wood Company were beyond the standard level. The amount of the collected wild cherry appeared to be above the standard level in Pylambara nursery and Company, Mazandaran Wood and Paper Company, Katoul New Wood Industry Company, and Mazand Flower and Fruit Company. Tilia species were collected at the standard level in Pylambara nursery and Mazandaran Wood and Paper Company. Finally, none of the companies and nurseries had collected fraxinus at the standard level and its amount was below the standard. Some of the main reasons behind the failure in achieving the standard levels in collecting seeds might be non-appropriate human force combination, education, and workers’ age range.

Tree felling is the most important component among tree harvesting components which has strongly effect on the tree harvesting processes. Manual tree felling is the most labor-intensive component of all harvesting operation and frequently represents a bottleneck in production. This research was carried out in 220 & 225 compartment of Namkhaneh district in Kheyroud FOREST. Objectives of this study were time study of tree felling operation, estimating of PRODUCTIVITY and costs of chainsaw, developing regression model and estimating crew, machine and budget. Factor affecting total felling time regression model (increasing order of importance) were DBH of harvested tree, direct of felling regard to the lay and inter-tree distance. The hourly production of chainsaw felling with and without delay time were 31.6 m3/h (7 tree/h) & 68.4 m3/h (18 tree/h), respectively. PRODUCTIVITY of chainsaw felling was increasing related to tree DBH as power. The unit cost of chainsaw felling with and without delay time were 8000 and 3700 Rials/m3, respectively. The unit cost decreased as simple exponential equation when DBH of harvested tree increased. Total felling cycle time without delay averaged 2.98 minutes and with delay time averaged 7.23 minutes.

Tree felling is the most important component among tree harvesting which has consists of cutting and, limbing and bucking. This research was carried out in two compartments in Namkhaneh district of Kheyrud FOREST. The Objects of this study were the time study of tree felling operation, limbing and bucking, estimating of PRODUCTIVITY and costs of chainsaw, and developing regression model. Factors that affecting on felling time regression models were DBH of harvested tree and inter-tree distance and limbing and bucking times were DBH of harvested tree. The hourly production of tree felling, limbing, and bucking without delay time was 76.9, 14.2 & 57.41 m3/h, respectively. PRODUCTIVITY of chainsaw felling, limbing, and bucking was increasing related to tree DBH as power. The total unit cost of chainsaw felling, limbing, and bucking without delay time with and without delay time were 63420 and 48730 Rials/m3, respectively. The cost of tree limbing consists of 70 percentage of total cost and bucking and tree felling operation consist of 17 and 13 percentage of total cost, respectively. The cost of felling, limbing, and bucking was increased as simple exponential equation when DBH of harvested tree was increased. The cycle time for felling, limbing, bucking, and delay averaged 3.1, 17.2, 4.2, and 6.1 minutes, respectively. Finally, we concluded that not doing the limbing and bucking until starting the skidding operation might cause many delays during the operation that should be considered.