فصلنامه تحقیقات جنگل و صنوبر ایران
سال بیست و یکم شماره 3 (پیاپی 53، پاییز 1392)

Oak (Quercus castaneifolia C.A.M.) is one of the most important forest tree species in the Caspian region of Iran and every year huge lands are purely planted by it. The aim of the research was to study characteristics of an even-aged planted stand (25 years old, 1.2 ha) of the species and proper management which lead to suitable tree form in future. For this purpose, diameter at breast height (dbh) and total height of all the trees and volume of 30 sample trees were measured. Results showed that although tree plantation was made only by oak species, but the stand today consists of 10 species as follows: oak (85.2%), horn beam (7.9%), iron wood (0.7%) and other species, including velvet, Cappadocian maple, elm, alder, and lime tree (6.2%). Most of the trees were classified at three diameter classes, including 10, 15 and 20 cm. diameter and height increment for trees with average dbh and total height of 15.3 m. and 16.4 m, were 6 and 66 mm. respectively. Mean dbh and height increment rates were 0.6 and 66 cm per year, respectively. Mean volume increment was 5.13 silve per year per ha. It can be concluded that according to our findings and other similar research results that diameter growth of oak in Iran is faster than its growth in Europe and might be utilized at lower age stage for veneer industry. Furthermore, stand structure in respect to trees form and mixture rate was studied and its trend process into mixed stand was silviculturally discussed and analyzed.

Forest structure is influenced by natural processes and human interventions. For proper forest management, some tools are required to study changes made at forest structure. In this study, to investigate changes made at structure of intact and natural forest of Kelardast area of Caspian Forests of Iran, three one-hectare area plots, representative of initial, optimal and decay stages of forest development, were used. After measuring distance and azimuth of each tree to the southwest corner of each sampling plot and recording some parameters such as species, diameter at breast height (dbh) and total height, three characteristics, including geographical location (Clark & Evans and uniform angle indices), mixture (Mingling index) and tree dimensions (dbh and total height differentiation indices) were studied, using a set of indices, based on nearest neighbor criteria. Results of this study showed that greatest density of trees was found at the initial stage and according to the Clark & Evans index, distribution pattern of the trees at initial and decay stages in one hand and at optimal stage at second hand was clumped and random, respectively. Furthermore, result of the uniform angle index showed that the trees arrangement within the structural groups at the three development stages was at random form. Results of Mingling index showed that mixture at initial stage was at lowest rate, compared to the other development stages. Moreover, result of dbh and total height differentiation indices showed that there were moderate-obvious and low-moderate variations for the trees at the three development stages, respectively. Regarding the intactness of the studied stands, results of these indices might be applied as a basis for similar forests and determination variation rates caused by natural processes and human interventions.

Although quite a few studies have been done in respect to forest structure and development in Iran, there is no study dealing with the evolution of lichens at different stages of forest development. For this reason the research has been carried out to study lichens diversity and identify reference and indicator species for each forest development stage at Gorazbon series of Kheyroud forest at Caspian region of Iran. After separating the different forest development stages at the series, sampling was made from all trees with more than 40 cm dbh at each stage, using a 40 x 60 cm frames to record lichens type and frequency. Richness, evenness, diversity and dominance indices at different development stages were calculated and compared, applying Variance Analysis and Duncan test. Results showed that there are significant differences between the development stages in respect to lichens diversity indices and they were the highest at destruction stage, except for Berger-Parker dominance index. Furthermore, results of Detrended Correspondence Analysis (DCA) showed that classification of the development stages in relation to the lichens cover data, leads to formation of specific groups with relatively high separation potential. Overall, 38 lichens species have been identified and according to Analysis of Indicator Species (IV) and Monte Carlo test, there were significant correlations between each of the optimal, ascension, and destruction stages of the forest developmental and 8, 17, and 13 numbers of lichen species, respectively, which are clearly found to be classified and differentiated with such significant differences.

One of the main and important knowledge for forest management and its optimal and sustainable utilization is to determine its trees volume and number and its production potential. Actually, future forest management is based on its inventory and information. Thus for a precise planning its required to have information about forest standing stock volume and increment, distribution of diameter classes curve and spices structure. Determination of annual allowable cutting is required for wood utilization planning and management, based on stands volume increment data. The research was conducted in Gorzbon district (934.24 ha) at Kheyroud Educational- Experimental Forest (Caspian region of Iran), using 258 permanent sample plots and applying the directed method of inventory to measure volume increment and trees number two times with nine year interval. Results showed that average trees number and stocking volume per hectare were 298.15 and 335.8 sylve in 2003 and 290.14 and 367.7 sylve in 2012, respectively. Although 31% of the forest tree number belonged to Fagus orientalis, but 57% of the standing stock volume belonged to this species. Volume increment was 4 sylve/ha/year and average trees number growth was 5.8 ha/year. Overall, the beech species had the greatest volume increment. In fact, such huge research area and data analysis was carried out for the first time in Khyroud forest and the results showed that applying permanent sample plots method provides essential and precise information and data for measuring forest increment

Continues occurrence of fire in northern forests of Iran during past years, necessitates conducting research, in order to predict future fire occurrence in these forests. For this reason a 1:25000 topographical map of Zarrin Abad Forests of Neka Township of Mazandaran province of I.R. Iran. was geo-referenced in GIS, firstly. Then digital model of elevation (DEM) with 30-meter pixel size was obtained from the geo-referenced map and slope, aspect and elevation maps were developed from the DEM. The vegetation cover density and residential areas (villages) maps were obtained from Nekachoob Corporation Company and digitized in GIS. All roads in the study area were routed using GPS and their map was developed. Then 200 and 500 meter buffers were considered on the maps, around the roads and the villages. All of the digital layers were classified according to Dong model. The fire potential map with five classes was developed by overlaying all of the maps, in GIS environment and allocating weight to each factor (map), regarding the Dong model. The past forest fires map was developed, using actual forest data and applying ground sampling with GPS. Then this map was overlaid on the forest fire potential map. Results showed that about 40 percent of the past forest fire areas are located on sites with very high or high fire risk which indicates the medium validity of the used model. Thus, Dong model was modified and weight of the layers was changed, based on their importance at the studied area and finally a new model was developed. A new fire potential map was generated, based on the modified model and was overlaid on the past forest fires map. Results showed that about 80 percent of the past forest fire areas are located on sites with very high or high fire risk which indicates a high validity of the used model for the studied area. It seems that the model might be applied for other forest sites at Caspian region of Iran, based on spatial locations of their watershed basins.

In this study effect of several environmental factors on growth rings width of three planted species, including: Alnus subcordata (22 year old), Juglans regia (21 year old) and Pinus brutia (15 year old) was investigated. In chronology studies, at first accordance among samples (15 samples for each species) was obtained then Average Species Sensitivity (ASS), Trees Correlation (TC), Expressed Population Signal (EPS), Signal-to-Noise Ratio (SNR)MS values were calculated. The purpose of this research was to develop a regression model in relation to effects of temperature, precipitation, actual evapotranspiration, Torentveit heat index, relative humidity (by month, season and growth period) on annual ring growth width in Educational and Experimental Forest of Sari Natural Resources Faculty. Overall, 162 independent climatical variables (temperature, precipitation, evapotranspiration, etc.) and 45 dependent variables (growth ring width) were analyzed. Results of variance analysis showed that there is a significant relationship between the three species in respect to their uniform growth ring width. Using filtration methods in multiple regression analysis, variables with lowest coefficient variation and highest coefficient indication were selected step by step. Results showed that growth rings width is positively correlated with summer maximum humidity in J. regia, but is negatively correlated with December maximum temperature and February evapotranspiration and is positively correlated with summer maximum humidity in A. subcordata whereas is negatively correlated with February humidity in P. brutia. These correlations are accordance with the ecological restrictions of the species. Finally, a multiple regression model was developed for each species and its accuracy was confirmed, based on model calibration results.

Quantitative, qualitative and structure data are vital for forest management at Zagros region of Iran. For this study, a site (40 hectare) at Blake forest located at Armardeh village of Baneh township was selected and 100 percent of the trees were measured, using 25 x 25 m. sampling plots. In addition to location of the trees in relation to the plot's corner, trees characteristics, including diameter at breast height (dbh),total height, crown height and crown diameters (biggest and smallest diameters) were measured at each plot. In order to identify the appropriate sampling method, for different methods were applied at 100 x 100 inventory net, consisting of: random sampling at three levels of sampling plots (40, 50 and 60 numbers, each at 10 R. area), and systematic-random at three levels of sample plots area (5, 10 and 20 R.), systematic-random with rectangular sample plots at two levels of area (10 x 50 and 20 x 50 m.) and transect 50 m. (length). The statistical methods of Anova and Duncan t were used to analyze the trees characteristics data and the %E2*T criteria to determine the appropriate inventory method. The horizontal and vertical structure of the forest was showed in 25 x 25 m. sample plot, using SVS software. The results showed that structure of Blake forest contains of two layers, in which Quercus infectoria and Quercus libani (average height of 7 and 6 m., respectively) make the over story, and Crataegus azarolus and Acer cinerascens (average height of 5 and 4.5 m., respectively) make the under storey. Furthermore, for diameter measurement (29222), transect and for total height (6048) and crown height (6668) measurements, Systematic –random with 5 R. sample plots at 100 x 100 sampling net system, recognized as the best inventory methods. Overall, the systematic-random inventory method with 5 R. sampling plots at 100 x 100 sampling net system is suggested to determine structure and measure characteristics of coppice and aged forests of Baneh township of Kurdistan province of Iran.

Moringa peregrina is a tree or shrub componend sub-tropical vegetation and extending from Dead sea and is scattered in Red sea and spread throughout northern Somalia and around the Arabian Peninsula to mouth of the Persian Gulf, Oman, UAE, Iran, Pakistan. In Iran it is limited to Hormozgan and Sistan&Balochestan provinces within Bashagard area to Pakistan and Iran boundary 100 to 1500 m. above sea level on mountain and foothills regions. The habitate of Moringa peregrina is locatated in Sahara- Sindian climatic region with hot summer, moderate winter and no frozen period, Mean annual rainfall 180-200 mm, Mean annual temperature 27ºC, Mean annual evapo-transpiration 3448 mm. Moringa often occupy Makran geological ranges, tertiary geology structural unit and Angohran, Roksha, Dar pahn and Guredak complexes. Stands parent material conclude sandstone, shale and mudstone. some time conglomera, limstome, volcanic and metamorphic stones present in bed rock. The results of soil analysis showed the soil texture in most stands is sandy- loam but in some stands are sandy-clay-loam, acidity is 7. 98 and electric conductivity 1. 78 des/m and no salt. M. peregrina is a evergreen plant and its growth therm is started in autumn when proper temperature and enough rainfall are occured، leaf buds begin to sprout and primary leave appear. These leaves are short-lived and start to fall in May when temperature go warm. White and pink flowers appear in February and March. Pod-like and green fruit appear on young branches in April and May. Fruit ripening start simultaneously maturity dates in July and seed are starting to drop in August. Rainfall during the Flowering time is induced the flowers are not inoculated and other phonological phases are affected. Dependence between Moringa and geological formation caused habitates are discontinuous mode. Individual distribution pattern in stands level is random pattern. Mean of density was about 29 trees in hectar, d. bs. 29. 6 centimeter, height was 3. 16 meter and canopy cover 3. 5% which are different in stands. Most trees are middle-aged to older and due to aging and environmental stresses as well as frosting periodic, most of Moringa is reformed to shrub and coppice type

The aim of the study was to determine the ecological factors influencing natural establishment and distribution of the medicinal shrub Juniperus communis at Arasbaran Forests of Iran. In order to start floristic studies, 97 sample plots (each 400 m2 area) were allocated in the studied area, based on the Minimal Area Statistical Method. Plant cover at different stories were identified and recorded, using the Modified Braun-Blanquet Method. After removing the organic layer of soil surface at the plots center, soil sampling was made at 10-20 cm depth. Soil physical and chemical analysis consisted of: organic carbon, total nitrogen, available phosphorus, exchangeable potassium, CaCo3, texture, Humus layer depth and pH. Two ordination methods, including DCA and CCA were applied to determine relationships between the species characteristics and environmental variables. Results showed that there is significant positive correlation between the Juniper density and exchangeable potassium and altitude and significant negative correlation with pH and CaCo3. The species preference to loamy and well drained soils was considered as well.

World anxiousness to earth global warmness brought a special attention to soil's potential for carbon sequestration. The purpose of the trial was to investigate effects of tree plantation on carbon sequestration at arid lands. For this reason, a site at forest park of Dehloran area in Ilam province of Iran was chosen where three tree species, including Eucalyptus camaldulensis, Prosopis juliflora and Ziziphus spina-christi had been planted before. Based on random systematic statistical method, 6- 10 sampling plots of 10 x 10 m. size were allocated for each species at planted and unplanted (control) parts, separately. Soil sampling was made in center of each plot at 0-20cm depth after removing the organic layer of the soil surface to measure carbon sequestration, N, P, K, pH, moisture, bulk density, silt, sand, clay and gravel amount. Results showed that carbon sequestration rate under the trees cover was 117.7 ton per hectare which was about five times more than the control plots (24.82 T/ha). Furthermore, only average carbon sequestration rate under P. juliflora plots was significantly more than under Z. spina-christii plots (p< 0.005). In addition, only average carbon sequestration at high density plots was significantly more than at low density plots under E. camaldulensis species. There was only significant difference between plots outside and inside crown cover of Z. spina-christii in respect to carbon sequestration rate. Overall, it might be concluded that forest plantation at Dehloran area played an important role in reducing atmospheric pollution and its area should be increased at high extent.

Carbon sequestration into plant biomass is an easiest and economically most practical way for dropping off CO2 from atmosphere. The current study was made for four poplar species, consisting of two natives (Populus alba and P. nigra) and two exotics (P. alba×euphratica and P. euphratica× alba), planted at Boldaji Experimental Station in province of Charmahal and Bakhtiari of I.R. Iran. Tree sampling was made randomly (10 trees for each species). After measuring the tree's characteristics including diameter at breast height (dbh), total height and crown diameter, they were felled down to measure the dry weight of different organs, including: (whole tree, trunk, main branches, twigs, leaf and bark of twigs and branches). The regression analysis was applied to find out relationships between mass production and poplar characteristics and to develop different allometry models between different organs and their carbon sequestration ability. The results showed that there are significant correlations to predict biomass for the whole tree's organs at each species. The independent dbh values, in Populus alba and P. alba×euphratica demonstrated high correlation against all the dependent variables (R2=0.95). On the other hand, the main trunk weight was significantly correlated to bark weight (R2=0.86), showed high accurate models. In P. nigra and P. euphratica × P. alba, due to forked stems, dbh didn’t prove any correlation with the tree's characteristics. At the same species, on the other hand, crown diameter was correlated to carbon sequestrated amount on all portions of the trees (R2=0.88). The research showed also significant priority of woody organs in comparison to leaf and twigs, when the prediction of the carbon storage is scheduled.

Natural plants are under risk of natural and human damages. Natural and human-made fires can change landscape and cause ecological disturbance, which can affect nature cycle of plant cover and ecological structure. The systematic random sampling method (50 x 50 m. network) was applied in two forest sites (each 15 hectares) at Marivan forests of Kurdistan province of Iran (burned and control) to layout 30 circular 2.5 acre and 30 four m-2 sampling plots on the burned and the control sites, for wooden and herbaceous plant species, respectively. Diversity, richness and evenness indices were calculated and compared, using the PAST software and Unpaired T- test method. The results showed that there was not significant difference between the two sites in respect to average sprout clumbs per plot. There were significant differences between the two sites (ρ<0.05) in respect to Simpson and Shanon diversity and Margalev richness indices for the wooden species, in which they were greater in burned site than in the control site. There was significant difference (ρ<0.05) between the two sites in respect to the herbaceous species density per plot. There were not significant differences between the two sites for the herbaceous species in respect to Shanon and Simpson diversity indices, evenness index and Margalev richness index, whereas there was significant difference between the sites for Menhinick richness index, in which it was greater in the control than in the burned site.

In order to determine the growth and yield of three pine species, this study was carried out in the forest and rangeland research station of Zaghmrz, located in East of Caspian sea shore. Treatments were Pinus pinea, P. longifolia and P. brutia. Their one year old seedlings were arranged based on randomized complete block design with three replications. Seedlings were planted with 3 meters interval in 1994. Seedling survival and quality and quantity characteristics were recorded and measured every year until the end of the eleventh. The results showed that there was no significant difference between the species in respect to survival, collar diameter and diameter at breast height. But the difference between the species was significant in respect to total height and quality of seedlings. The survival rate ranged from 82.43 percent for Pinus longifolia to 95.68 percent for Pinus pinea at the end of the eleventh. The mean rate of d.b.h ranged from 9.49 for P. longifolia to 12.23 centimeters for P. brutia. The greatest amount of high quality individuals respected to P. pinea and then P. brutia. Based on Duncan multiple analysis species grouped in two sections. The first group allocated to P. brutia with 591 centimeters of total height and the last related to P. longifolia with 287.67 centimeters of total height. At the end of the eleventh, the stuck productions were 40.02 m3, 19.67 m3 and 10.48 m3 for P. brutia, P. pinea and P. longifolia respectively. The mean annual diameters increment were 12 millimeters, for P. brutia, 10.5 millimeters for P. pinea and 9,2 millimeters for P. longifolia. The mean annual height increment was 59.5 centimeters, 40 centimeters and 9.5 centimeters for three mentioned species respectively. Pinus brutia and P. pinea showed a good adaptation at the mazandaran east see shore until the eleventh.

Trials of exotic variaties of Poplar species and their wood production potential at Guilan province (Caspian region) of Iran have been started after 1960s. Some ecological requirements and exceptions might positively od negatively affect the poplar's adaptation process. The trial was conducted under statistical desighn of Randomized Complete Blocks with three poplar clones (three treatments) including: P.deltoides 69.55, P. eurameracana 214 and P. deltoids 9.51 and four poplar plantation sites (four replicates) located at lowlans of west Guilan province, including: Tolaroud, Shanderman, Gisum and Haft-daghanan. Popar plantation was made in plots with 2000 m2 area (50 x 40 m.) and 3 x 4 m. spacing. The measured and calculated popolar characteristics consisted of: diameter at breast height (dbh), survival, total height and volume. Results showed that there were significant differences between the poplar clones and the poplar sites in respect to growth characteristics (ρ< 0.01). The greatest volume increment at Tolaroud site with sandy loam soil belonged to P. euramericana 214, at Shanderman site with clay sandy loam soil belonged to P. d. 79.51, at Gisum with sandy soil belonged to P. d. 79.51 and at Haft-daghanan site with loamy soil belonged to P.d. 69.55 (20.31, 23.5, 24.2, 25.4 and 26.9 m3/ha/year, respectively). Poplar and site classification, based on volume, diameter, height and basal area data showed that the first rank achieved by Haft-daghanan and Tolaroud sites and P. d. 79.51 clone, respectively. The best rate of quality achieved by P. d. 69.55 clone at Gisum site.

In order to identify the best sowing depth and seed cover of Quercus brantii Lindl., a trial was conducted at Kamfirouz Oak Experimental Station in Fars province of Iran at two year period, using Factorial statistical method and experimental design of Randomized Complete Blocks at four replicates. The first factor was depth of seed sowing at six levels (0.0, 2.5, 5.0, 7.5 and 12.5 cm) and the second factor was seed cover at three levels (ordinary forest soil or control treatment, mixture of ordinary soil and 20% manure, and mixture of ordinary soil and 50% manure). The measured characteristics of established oak seedlings consisted of: survival, root and shoot length and shoot and root wet and dry weight. Data analysis was performed, using Variance Analysis and Duncan test and applying SAS software. The results showed that effects of year, seed cover and sowing depth on survival were significant (p< 0.01). Average seedling survival at first and second year of trial was 32.7 and 40.5 %, respectively. Increased amount of manure in seed cover material increased survival significantly and it increased from 33.8 % in ordinary soil to 40.7 % in soil and 50 % manure mixture. Greatest percentage of survival at 2.5, 5.5 and 7.5 cm sowing depth was 47.7, 49.3 and 51.6 cm, respectively, whereas the lowest rate (10.1 %) belonged to zero sowing depth. Overall, the highest rate of shoot length, root length, shoot dry weight and root dry weight were 11.8 cm, 80.3 cm, 4.8 g and 3.4 g, respectively.

Due to Eucalyptus potential as a fast growing species, its utilization for afforestation and industrial and medical purposes is very important. E. maculata Hook. is an important species among the other eucalypts in respect to some chemical components production and medical utilization. Sexual and asexual propagation of this species is difficult, for this reason the trial was conducted to investigate its propagation by tissue culture, using micro mature stocks.The produced explants from the mature stocks, were placed on MS medium (Murashige and Skooge) treated by ½ nitrate and various growth regulators such as Kin (Kinetin), BAP (Benzylamino purine), IBA (Indole-3-acetic acid), 2ip (2-Isopentyladenine), TDZ (Tidiazorun) and NAA (Naphtalen Acetic Acid) at different levels of concentration. After two months, growth indexes, including shoot number, shoot height, root number, root length, bud number and greenness rate were measured and recorded. Results showed that the best shooting treatment was IBA (0.01 mgl-1), BAP (0.3 mgl-1) and 2ip (0.5 mgl-1), in which average shoot number, shoot height and greenness rate were 4.63, 2.73 cm and 3.75, respectively, whereas the best rooting treatment was NAA (0.5 mgl-1) plus IBA (0.5 mgl-1), in which root length was 0.2 cm. Finally, the micropropagated plantlets were transferred to greenhouse to pass their adaptation process.