Iranian Journal of Forest and Poplar Research
Year:2017 | Volume:25 | Issue:3 (69)|Papers Count:20

Logging secondary damages on remained trees are one of the challenges in management of uneven-aged stands which have been less studied in the northern forests of Iran. In this research decay frequency and volume of bole trees after 15 years from wound occurrence were studied through systematic-random sample plots with 1000m2 plots in the Nav-e Asalem forests, Iran. The conditions of trees were registered in two types: safe and wounded, the wounds were registered in two types: open and decayed; and volume of decayed bole was calculated by Smalian formula. Results indicated that 16.1% of wounds were led to bole decay. Decay frequency and volume were estimated to 5.5 trees ha-1 and 1.7 m3ha-1, respectively, that includes 1.96% of total trees and 0.72% of total stand volume. Coefficients of decay frequency and volume on the base of frequency of logging primary damage (12.2%) were calculated 0.16 and 0.06, respectively. Decay frequency of wounded trees bole were related with tree species, wound location, diameter at breast height (DBH), situation of wounded tree in stand, and slope aspect. Decay frequency and volume in the trees of lime and oak were more than other tree species. Decay frequency was increased by decreasing wounds distance from ground. Decay frequency and volume in the high diameter wounded trees were more than low diameter wounded trees. The wounds on the trees in edge of skid trails were more decayed than the other wounds. Decay frequency of wounded trees on the northern aspect slopes were more than the southern aspect slopes. In general, minimizing of primary logging damages, reducing harvest intensity, increasing logging period, and harvesting bole-decayed trees in the next logging periods are suggested.

Soil compaction, as one of the causes of stress, has a negative impact on plant growth. The aim of this study was to evaluate the effect of soil compaction on root system of Caucasian alder (Alnus subcordata C. A. Mey.) seedlings in controlled condition. After sowing of alder seeds in plastic pots in loamy or clay-loamy soils with constant moisture regimes, the reaction of seeds were evaluated under six levels of soil compaction. Collar diameter, length, biomass, and allocation ratio of root system were measured and calculated. According to the results, the studied parameters decreased significantly by increasing soil bulk density and their trend were downward quadratic, except ratio of lateral root length to main root length. Thirty six percent decrease in the mean of lateral root length, 31% decrease in the mean of main root length, 37% reduction in the mean diameter of main root and 27% fell down in the mean value of root dry biomass was recorded in treatments with different levels of soil compaction in compare to the control treatment. In general, results indicate that compaction tension has negative effect on the characteristics in the root system of Caucasian alder seedlings.

Study of natural stands structure as well as knowledge of developmental stages and dynamic process in the natural forest stands for applying close to nature silviculture methods, ensures multiple functions of forests such as ecological balance and socioeconomic needs assessment. The aim of this study was to quantification of the structural characteristics of natural mixed oriental beech (Fagus orientalis Lipsky) stands in the optimal stage. For this purpose three sample plots, each one ha (100 ´ 100m), were selected in the compartment 326 of Gorazbon district in the Kheyrood forest, and height and diameter at breast height (dbh) of all trees with dbh larger than 7.5 cm, as well as quantitative and qualitative characteristics of deadwoods were recorded. Results showed that hornbeam and beech were the most frequent species in the sample plots with frequency of 52.8 and 37.7 percent, respectively. Mean volume of the stands was 629.2 m3 ha-1, whereas the mean volume of deadwoods was 13.4 m3 ha-1. Diameter distribution of live trees and deadwoods indicated the maximum presence of trees and deadwoods in the small timber size (<35 cm diameter) class. Height distribution of hornbeam and beech trees indicated the maximum frequency in the height classes with less than 15 meter and 15 to 30 meter, respectively and beech was the dominant species in the upper layer. The results of this study which was conducted in the control compartment could be used as a basis in other forest stands for silvicultural, harvesting and rehabilitation operations.

In recent decades, poplar cultivation as wood farming has been developed up to 50 thousand hectares using the fast growing eastern cottonwood (Populus deltoides Bartr. ex Marsh. 77.51) has become a common practice in north of Iran. The current study aimed to select appropriate sites for increasing growth and yield of this poplar clone. For this purpose, three different 20 years-old plantations on three different media naming: loam, silt-loam and silt-clay-loam soils of Noor alluvial plain in north of Iran were selected. The measurements were carried out based on 400 m2 plots with four replications. Quantitative and qualitative analysis showed significant differences among poplar trees grown on different soil textures beds. The poplar trees grown on loamy soils displayed the highest annual height increment of 1.27 m and volume of averaged tree of 0.956 m3. Values for average diameter, basal area and volume ha-1 were also highest in trees grown on loamy soil with total 29.1cm, 32.59 m2 ha-1 and 443 m3 ha-1, respectively. The mean height of the trees in the silt- loam soil (24.47 mm) was significantly greater than that of the silt- clay- loam. Values for diameter increment and basal area of trees were higher in the silt- clay- loam than in silt- loam soil. In order to get an initial understanding of the habitat condition, clone selection and improvement operation, analyzing of soil is essential prior to planting of trees. In this case we can ensure and guarantee the plantation and the investment would be less risky.

In order to solve problems in working environments, especially forestry operations which are classified as hard job, the physical health of the staff should be studied and monitored. The objective of this research was to monitor the health of staff in forest management plans of western part of Golestan province. In this study, 42 forestry personnel including forest guards, administrative personnel and heavy machines drivers were selected. Anthropometry information including age, height and weight of personnel was measured annually and then body mass index (BMI) and basal metabolic rate (BMR) was calculated. The blood pressure of personnel was measured using pressure meter for five years (2010-2014) and the cholesterol, triglyceride and blood sugar was measured for three years (2012-2014). Results showed that the BMI with high value for administrative personnel was significantly more than that of other groups. Weight of forest guards was more ideal and natural in compare to other groups. Basal metabolic rate for heavy machines drivers, administrative personnel and forest guards were 1804.88, 1766.63 and 1747.98 calories, respectively. Blood sugar and cholesterol significantly increased during years of 2012 to 2014. Forest guards had the highest blood sugar and heavy machines drivers had highest blood cholesterol in compare to other groups. Lowest triglyceride was observed for administrative staff. Ninety one percent of administrative personnel had normal systolic blood pressure and 100% of them had normal diastolic pressure which indicates better condition in compare to other groups.

This research was conducted to study the site demands of Tamarisk (Tamarix romosissima Ledeb.) in Ilam province. At first the sites that tamarisk was dominat, including Zoheiri, Darbalut, Cham Jangal, Pol-e Saymereh, Banroshan, Golan and Konjancham regions were recognizes. In each selected site, five soil samples were taken randomly from the depth of 0-30 cm and soil physicochemical properties including pH, electrical conductivity, organic carbon, total nitrogen, phosphorus, potassium, texture, moisture, bulk density and particle density were determined. Our results indicated that T. romosissima can tolerate 0.92 to 9.03 ds/m salinity, pH between 6.9 and 8.0, organic carbon between 0.09 and 3.39%, total nitrogen between 0 and 0, 29%, phosphorus between 17.17 and 23.14 ppm, potassium between 2, 35 and 402.35 ppm and soil moisture between 0.06 and 30, 56%. One-way ANOVA results revealed that sand, silt, clay, moisture, electrical conductivity, pH, phosphorus, potassium, total nitrogen, and organic carbon were significantly different in the studied sites. The principal component analysis and TWINSPAN results revealed that distances from river, organic carbon content, electrical conductivity, soil moisture, phosphorus and silt are among the most important factors affecting the presence and distribution of T. romosissima.

The aim of this study was investigating the social effects of Brant`s oak (Quercus brantiiLindl.) decline from the forest dwellers point of view. The sample size included 216 persons of Malekshahi county in Ilam province using Cochran formula and stratified-random sampling method. Data were collected by distributing a questionnaire prepared based on the research background, literature review and interview with experts. Factor analysis with exploratory approach was used for identifying and categorizing social effects of oak decline. Based on results, the effecting factors could be categorized in eight groups. Reduction of life quality (12.60%), reduction of responsibility (10.64%), reduction of social participation (9.88%), reduction of social trust (9.70%), reduction of social network of relationships (8.56%), changing attitudes to agriculture and animal husbandry (6.94%), reducing satisfaction from the government (6.78%) and increase in migration (4.91%) were most important factors and social consequences of oak decline on villagers. The mentioned factors explained 70.02% of the total variance. Hence, one can conclude that maximum social impact of oak decline would affect the life quality of people in the study area.

The response of plants to water available for strategy codification of water resources and irrigation is very important. In this study, evapotranspiration, crop coefficient, yield and water use efficiency in two species of Eucalyptus (Eucalyptus flocktoniae (Maiden) Maiden, E. leucoxylon F. Muell.) through lysimeter experiments were determinated under different soil moisture levels (100%, 70% and 40% of field capacity). The research was designed as a factorial experiment on a completely randomized design with three replications in Yazd climatic conditions. The results showed that with increasing soil moisture in both species, evapotranspiration increased, so that there were significant differences between the different levels of soil moisture treatments (p< 0.001). E. flocktoniae and E. leucoxylon had water requirement in 100% of field capacity treatment, 1185 mm and 1617 mm with 0.65 and 0.88 crop coefficients, respectively. Dry matter produced in all parts and the water use efficiency (WUE) of E. leucoxylonwere significantly higher than that of E. flocktoniae, Water use efficiency measured in E. flocktoniae and E. leucoxylon, were 1.22 g/lit and 1.41 g/lit, respectively. Although the growth rate of E. leucoxylon is faster than E. flocktoniae, therefore its water requirement is higher, but considering an appropriate mechanisms for drought adaptation, it could be introduced for afforestation and wood production in arid and semi-arid regions.

In recent years, oak decline phenomenon has caused severe damages in Zagros forests. To deal with and managed this crisis, prior to any action, having accurate information about the status and distribution area of this phenomena is necessary. Using satellite data is one of methods to achieve information on the extent and severity of die back. For this purpose, map of oak decline severity was prepared in four levels for some parts of Ilam forests using Worldview-2 satellite data. Maximum likelihood, naive bayes, Knearest neighbors and artificial neural network classification algorithm were used. The results showed that among different classification methods, the results of artificial neural network classification algorithm had most overall accuracy with 72.83%. Moreover, our results confirmed that the Worldview-2 satellite data can illustrate the severity of oak decline.

Spatial pattern is an important parameter in ecology of forest communities. Lebanon oak (Quercus libani Oliv.) as a native species, covers 24% of northern Zagros forests. Quercus libaniplays a significant role in ecological and social conditions of local people. Hence, the present study was conducted to investigate the spatial pattern of this oak species based on T-square sampling in Belake forests, northern Zagros. For this purpose, a 40-ha area was inventoried based on distance method. Systematic- random method with 25´25 m2 plots was used for inventory. A total of 43 random points with 100m distance were determined. Eberhardt, Hines, Hopkines, C index and Index of dispersion were used for dispersion pattern and the results were tested at 5% level. Eberhardt's index, Hines, Hopkines and Index of dispersion showed disperse pattern, while C index indicated clump pattern. But only Eberhardt's index result was significant. Our results can be applied as a useful tool in developing the management programs, afforestation and reforestation programs in order to protect the endangered ecosystems.

Mahaleb cherry (Cerasus mahaleb L.) is endangered due to its limited ecological distribution, weak natural regeneration and seedling propagation problems. In order to determine suitable methods for rooting and seedling production of C. mahaleb by hardwood cuttings with treatments of auxin in November and March, an experiment was carried out in a complete randomized design. Treatments were application of Indole Butyric Acid (IBA) at concentrations (0 as control, 500, 1000, 2000, 3000, 5000, and 8000 mg l-1) and Naphtaline Acetic Acid (NAA) at concentrations (0 as control, 500, 1000, 2000, 3000 and 4000 mg l-1). After rooting, rooted cuttings were transferred to the field condition in fure rows with 70 cm distance. After one season of growth, five seedlings were excluded of the substrate and assessed for characteristics. Results showed that concentration of 2000 mg l-1 IBA and 1000 mg l-1 NAA in both of November and March are the best treatments for the percentage of rooting, total seedling dry weight, root area, leaf area, height, relative water content, and chlorophyll characteristics. High auxins concentration caused a decrease in all the characteristics studied. Percentage of rooting and chlorophyll were significantly higher in November than to March in auxin treatments. It is concluded dipping in 2000 mg l-1 IBA is the best treatment for rooting of its hardwood cuttings.

After 20 years, the effects of five plantations of Acer velutinum Boiss., Cryptomaria japonica D. Don., Cupressus sempervirens L. var. horizontalis (Mill.) Gord., Pinus taedaL. and mixed stand on soil fertility and quality of the stands were investigated and compared with natural forest to determine the appropriate species for planting in low land of Hyrcanian forests. Five 400 m2 plots were selected randomly- systematic in each stand. Quantitative and qualitative characteristics were recorded. Also, within each plot soil in 0-15, 15-30 and 30-45 cm depths were sampled. The results showed significant effect of reforestation on pH, EC, bulk density, organic carbon, total nitrogen, phosphorus and carbon sequestration in the soil. According to the result, P. taeda has the highest pH (4.6) while A. velutinum has the lowest pH (5.5), natural forest stand has the highest (18.0 ds/m) whereas C. japonica has the lowest (06.0 ds/m) EC. Pinus taeda has the highest organic carbon content (1.29%) and total nitrogen (0.36%) but the natural forest has the lowest amount of organic carbon (1.03%) and total nitrogen (0.08%). The mixed stand has the highest phosphorus (1.9 g/kg) and C. japonica has the lowest one (1.8 g/kg). The A. velutinum has the greatest (292830 Mg/ha) while the natural forest has the lowest (223920 Mg/ha) amount of carbon sequestration. The results showed the conifer stands have been more successful in terms of tree quality characteristic while broadleaf stands were more successful in the quantitative characteristic. Finally, it can be claimed that broadleaves stands were more successful in compare with conifer stands.

Stand structure and species diversity are two useful parameters for complex assessment of forest biodiversity, and provide important information for management and decision making for appropriate silvicultural system. For this purpose, five one ha plots were selected randomly in homogeneous ecological units of beech-hornbeam type in Nav-e Asalem, Gilan province. In order to determine complex structural diversity index (SI) in the studied forest type, uniform angle, mingling and DBH dimensions difference indicators were calculated. Also in order to determine density of trees, the nearest neighbors distance index was used. According to the results, the average value of nearest neighbors distance index was calculated to 5.58 meter. Mean uniform angle index was 0.52, which indicates clumped distribution of trees. Mean mingling index (0.45) indicates moderate mixture of the studied mixed stand. The amount of DBH dimensions difference index was 0.47, indicates moderate difference between trees diameter at breast height. The complex structural diversity index which presents three dimensions of structure, including diversity of spatial pattern, species diversity, and diversity of DBH dimensions) was calculated to 0.475. This value confirms a high level of tree diversity. The results of this study provide key information for management and maintaining of tree diversity in the studied mixed beech-hornbeam stand. Also with monitoring and management of tree diversity level we can reduce the negative impact of natural and human factors.

The Juniperus habitat has the second most natural distribution in Iran after the pistachio. The habitat area of Junipers has decreased due to its low rate of natural regeneration which makes the rehabilitation of this species very important. The aim of this study was to evaluate the maternal tree morphology and irrigation on survival and growth parameters of Greek juniper (J. excelsa M. B.) in Sirachal research station in a four years period. Twenty produced seedlings from three different maternal tree morphology including A (cylindrical), B (non-cylindrical) and C (high production of seed) were planted in Sirachal research station as complete random blocks in split plots with three replications in 2010. Seedlings were irrigated every fifteen, thirty and forty days in the first year. Controls were not irrigated. Statistical analysis showed that in the first year, the effect of irrigation was significant on growth parameters including current diameter growth, current height growth and crown cover. The effect of maternal tree morphology was significant only on current diameter growth in the first year. In the second year, only the effect of maternal tree morphology was significant on crown cover. After four years of measurement, the effect of irrigation was significant on crown cover. According to our finding, it seems, irrigation for one time in planting time, is an important necessity for Juniper establishment and should be concerned in rehabilitation of habitats. In addition, due to the effects of maternal tree morphology on seedlings survival, establishment and growth, using trees with C morphology will be effective in juniperus rehabilitation habitat.

Decision-making in natural resources often leads to complexities beyond the statistical empirical methods, therefore we need new solutions than algorithmic methods. Artificial neural networks (ANN) technology mimics the human brain in the process of problem solving. The aim of this study was to predict the commercial volume and cordwood volume using this technique (Artificial Neural Network). For this purpose, 367 marked trees in the experimental and educational forest of Kheyrood were selected. Some factors including diameter at breast height, diameter at stump, stump height, total height, topographic factors (slope, aspect and elevation), species, tree situation and minimum median diameter of last log were measured. The factors were considered as input network. Multi-layer Perceptron network (MLP) was used for modeling. The result showed that Multi-layer Perceptron network (with the 0.94 and 0.71 R2, and 0.233 RMSE) has acceptable accuracy to predict the commercial and cordwood volume.

Non-wood forest products (NWFPs) play a main role in rural household’s economy directly and indirectly. In developing countries, livelihood of 600 million people depends on these products. NWFPs are important in increasing income and improving the economic situation of rural areas with high forest density. The aim of this research was to estimate the amount of production, collection, role of cherry plum (Prunus divaricate Ledeb.) fruit in household’s income at Rudsar county of Gilan province. In order to estimating of fruit production, inventory was done systematically- randomly with 30 sample plots of one hectare (with dimensions of 100 by 100 meters) each. To estimate the collection and contribution of NWFPs in total household income, 120 households was censed at three villages by the semi-structured interviews and direct observations in summer 2015. The correlation analysis between tree traits and fruit production showed that diameter at breast height (DBH) had a high and significant correlation (0.64) with fruit production. The mean fruit production was about 8.5 kg per tree. Average tree density was 13 tree per ha. Total fruit collection and annual average collection by households was 3500 kg and 29 kg, respectively. Net annual household income from fruit harvested varied from 500 to 2600 thousand Rials. The fruit collection creates employment for 11 person’s day per year. We conclude that income of fruit collection is not much and we can increase it by much processing and market expansion.