Iranian Journal of Forest and Poplar Research
Year:2009 | Volume:17 | Issue:3 (37)|Papers Count:16

In order to cooperate with the Iranian Olive Development Project, the importance of the holy tree of olive and to achieve the most adaptable varieties of olive to climate conditions of Lorestan province, a trial was conducted in 2001 to investigate the most adaptable varieties of Olea europaea L. species. For this reason, 10 varieties of olive, including Konservalia, Roghani Roudbar, Gorgan A, Gorgan B, Mishen, Roghani Mahally, Roghani Gorgan, Amfisis, Zard and Shengeh were used as treatments under randomized complete blocks design with four replications at Kamalvand experimental station in Khorramabad city. At each plot, 20 seedlings were planted at 5m×5m spacing. According to the results, the varieties of Zard, Roghani Roudbar, Roghani Mahali and Gorgan B had the highest survival rate. The varieties of Zard and Roghani Roudbar showed the highest height growth. The varieties of Zard and Roghani Roudbar showed the highest collar diameter growth, whereas the varieties of Konservalia and Mishen showed the highest fruit production ability.

Quercus castaneifolia is one the most valuable species of northern forest in Iran. Therefore, study and determination of feasible time of planting is important for this species. This research was conducted in low and middle altitudes of Shafaroud watershed with 3 replications in six treatments including of planting of one year old seedlings in December, January, February, March, April and storing in March and planting in April. The study was carried out for 10 years continuously. In each plot 100 seedlings were planted in a spacing of 1m×1m. Totally, 1800 seedlings were planted in each zone and a sum of 3600 seedlings was used in this study. At the end of growing period, the survival percentage and height of 36 seedlings in the middle of each plot were recorded and ten years results showed that there was no significant difference among treatments (P<5%).

This study was carried out in the Pistachio forests of Khajeh Kalat with an area of 6393 ha. In order to study the effect of physiographical factors (aspect, slope and altitude) on qualitative and quantitative characteristics (crown area, viability and vigority) of pistachio, a land survey was conducted. Sampling performed by 48 plots in random design established on overlaid maps of aspect, slope, altitude, created by GIS softwares. Results showed that slope, aspect and altitude have significant effect on crown area of pistachio. Aspect and slope showed significant effect on pistachio vigority. Results also showed slope, aspect and altitude had no significant effect on viability. 

Phenological characteristics of Pistacia atlantica Desf subsp. Mutica (F. & M.) Rech were investigated at two different sites of Khalkhal Forests (Mazrae and Kandiragh) at two altitudes (1450 and 1650 m.a.s.l) and one aspect (south), during the years of 2001 to 2003. For this study, 30 trees at each site were selected and registered. The study started at March (beginning of the growing season) and ended at full leaf fall of each year. Every 7-10 days, the phenological characteristics were measured as date of budding, date of leaf formation, flowering, fruiting, fruit ripening and leaf fall. Statistical analaysis was done by compound analysis of variance method. Results showed that date of budding is between 3rd and 4th week of April, flowering between 4th week of April and 1st week of May, fruit set between 2nd and 3rd week of May, fruit ripening between 4th week of October and 1st week of November and leaf fall between 1st and 2nd week of December. The statistical analysis showed that there were significant differences beween the phenological characteristics and two altitudes. There was significant negative correlations between average rainfall and date of budding and flowering.

In order to determine the suitable sampling method for estimating of stem number per ha and percentage of canopy cover in the protective western oak forests of Iran (Zagros), a survey was carried out in Kermanshah province. For this purpose and based on cost and precision (E%2×T) criterion, two sampling methods: 1- transect by distance measurement between trees and 2- circular plot with area of 1000m2, were carried out in 50 ha area of the educational and research forest of Razi University, which was already surveyed by 100% inventory. For each sampling method based on systematic-random sampling design with 100m×100m dimensions, 50 samples were selected. In each sample plot and transect, the number of trees and some characteristics of trees such as number of coppice shoots, the least and highest crown diameter were recorded and measured. Results showed that the more suitable method for these forests in west of Iran is the circular sample plot with 1000m2 area.

In order to adopt strategies for conservation and development, it is necessary to estimate the amount and distribution of genetic diversity in existing populations of poplar. In this study, for estimating genetic diversity between and within 12 stands of Populus nigra established at Kermanshah and Zanjan provinces in Iran, morphological traits were measured. In order to assimilate environmental conditions, seedling were planted under randomized complete blocks design with 3 replications. In the middle of growing season, 23 morphological traits were measured and data were analyzed using analysis of variance, cluster and principal component analysis. Results showed significant differences between stands. Principal component analysis introduced traits with high weight in components. Finally, by using cluster analysis, stands were classified in 2 groups based on 2 different provinces. Results showed that in homogeneous conditions, morphological traits could reveal diversity and similarity in poplar stands.

Poplar is a one of the fast growing and prolific species that is used for afforestation programs. Advising agro-technical methods with attention to ecological aspects is one of the effective and important factors in integrated management of pests. The object of this investigation is studying the effects of different weeding treatments (complete weeding, monthly weeding and no weeding) on diameter and height growth of poplar seedlings, evaluating variation of different weeding treatments and also identifying weeds of poplar nurseries and studying their effects on population densities of Chlorophanus votuptificus, Slatymycterus marmoratus, Stauronematus compressicornis and Paranthrene tabaniformis, which are important pests of poplars in the nurseries. Statistical analysis of the obtained data did not show any statistical differences between the treatments in survival percentages of the seedlings. Diameter and height growth of healthy and infested seedlings to poplar gall inducing moth was not affected by weeding treatments in the years 2001-2002. However, in the years 2003-2004, a significant difference was observed between different weeding treatments in diameter and height growth of seedlings (P<0.01). The three weeding treatments had no significant effect on population densities of Chlorophanus votoptificus, Stauronematus compressicornis and Paranthrene tabaniformis, but in 2004, density of this pest was different in various treatments and a significant difference was observed in P<0.01. The highest number of insects was in monthly and the least was in weakly weeding treatment.

Present research was aimed to study 1- the effect of soil-media on seed germination of Pinus halepensis Mill. and 2- the increase of seed germination and seedling production in nursery of Koloudeh, located in Amol city, Iran. Seeds were sown in plastic pots at four different soil treatments including: a- nursery soil (control), b- control soil+ cattle manure (5:1), c- control soil+ litter (5:1), d- control soil+ cattle manure+ litter (5:1:1). The experiment was set up as completely randomized design (CRD) with four replications. Results demonstrated that among the soil treatments there was a significant difference in attributes as germination rate, mean daily germination and germination energy but no significant differences were found in maximum mean daily germination, germination speed, mean germination time, germination value and Kotowski coefficient of velocity. There was a highly significant correlation between germination rate and mean daily germination with different soil composition. Seed germination rate was highest where decomposed litter was mixed with control soil+cattle manure+ litter (5:1:1). From this investigation it is deduced that organic matter improves seed germination of Pinus halepensis, due to the suitability of seedbed. Thus, it can be proposed that in order to enhance the qualitative and quantitative of seedling production of this species, the condition of soil-media should be better considered in nurseries.

Fagus orientalis Lipsky accounted for 24 percent of stem number and 30 percent of total volume in northern forests of Iran. The aim of this research is finding the regularity in frequencies of diameter increment, determining the relationship between tree age and fluctuations in radial increment of beech trees. Several hypotheses including stationary, secular trend, cyclic and random variations in data series of the beech tree increment, were examined to find out the main effective factor on variations. Four sound beech trees with mean diameter of 10 cm and maximum age of 350 years were selected. One disk was prepared at breast height from each sample tree. Then rings width was measured and data processed with the Time Series analysis. Results showed that there is more than one trend (model) in radial increment diagram of the sample beech trees. Positive correlation was calculated between tree age and radial increment up to the age of 120 years, where as this correlation turns to negative after this age. The mean and distribution of radial increment differ in periods of tree life. Radial increment of the beech trees is fitted with cubic model along the two age periods. Volume trend of annual increment always is positive and is not inversed. Autocorrelation diagrams show one year periodicity for the fluctuations of radial increments. The other periodicities are irregular and the alterations are not statistically significant.

Morphological characteristics are important variables applied in forest inventory practices. This paper investigates such variables as diameter at breast height, basal area, height, crown length and width, volume, trunk length and ratio and slenderness coefficient as well as stem branching behavior on 289 stems in a pure stand and 259 stems in a mixed stand with uneven-aged structure in Gorazbon district, North of Iran. Results show no difference between two stands except for height and trunk length which is significantly higher for pure stand while there is no significant difference (a=0.05) for all concerned variable for beech trees between the two stands.

In order to determine the relationship of soil characteristics and topographic conditions with tree and shrub species, three compartments of district 16 of Shafaroud forest, Guilan, Iran were sampled by sixty 0.1 ha plots. In each plot, diameter of all trees and shrubs (DBH>10 cm), altitude, slope and aspect were recorded and soil samples were taken at 0-20 cm depth. Total of basal area for every species in each plot was calculated. Using TWINSPAN (Two-Way Indicator Species Analysis), the forest was classified in five types, and then 6 soil profiles were excavated in them. The relationship of forest types with soil characteristics and topographic factors were analyzed by CCA (Canonical Correspondence Analysis), ANOVA (Analysis of variance) and Tukey's method. Based on the statistical methods, elevation, slope, soil pH and Ca showed significant relationship with forest types. Alnus- Juglans and mixed forest types had a significant relationship with elevation, soil pH and Ca. High correlation in Fagus-Tilia and Fagus- Fraxinus types with slope was recognized.

To evaluate the capability of SPOT5 HRG and IRS-P6 LISS-III in separating the pollarding areas of northern Zagros forests and preparing the map of this area, some parts of pollarded forests located at Baneh city were selected. The pollarding areas (Shan, Kurpe, Khert and Koor) were determined as ground truth in a 3 year alternation period using a global positioning system (GPS). Assessing the radiometric quality, no radiometric error was observed in these data. SPOT5 data which had been already geometrically corrected was used as basis for geometric correction of IRS-P6 color image and IRS-1C panchromatic image. Nonparametric method was used to do geometric correction with Root Mean Square Error (RMSE) of 0.54 and 0.75 pixels for these tow images, respectively. Principal component analysis (PCA) and various spectral rationing methods were used to prepare artificial bands used in data analysis. Likewise, for more image enhancement, HRG and LISS-III multi-spectral bands were fused with IRS-1C pan image. The data was classified using a maximum likelihood (ML) algorithm. This classification was applied using 4 and 6 classes for the studying area and a classification with 3 classes was used for each northern and southern aspects. The separability of classes was studied using Bhuttacharrya Distance Criteria. Result showed that separability of different classes of northern aspect was better than southern aspect. Likewise, northern Khert and agriculture classes were completely separated from other classes. The vegetation indices showed lower results compare to the original bands. Fused bands of SPOT 5 images showed the highest overall accuracy is equal to 65.3% and the highest Kappa coefficient is equal to 0.63. The highest overall accuracy (70%) and Kappa coefficient (0.60) was obtained using the first component analysis resulted from PCA in combination to bands 1 and 4 IRS-P6 data. According to the results of classifying of these two images, the data obtained before pollarding and during of vegetation growth season, showed better results. Regardless of spectral interference between soil and trees crown cover, the results showed the high capability of above mentioned images to separate the pollarding areas and to prepare the map of the area.

The study area is located in Kheyroud forest which was burned in 1998. This study was carried out to evaluate forest fire effect on diameter growth of beech (Fagus orientalis L.) and hornbeam (Carpinus betulus L.) after 7 years. After surveying whole burned and control area, 60 cores using increment borer were provided from both beech and hornbeam (15 cores were provided for each species in each area). Then sample’s ring growth width was measured. Statistical analysis was conducted on data which classified in years before and after fire. Furthermore, correlation between ring growth width and climatic data was tested. Results showed that the surface fire didn’t affect on beech but hornbeam ring growth was increased significantly. The correlation within ring growth width and climatic data had been recognized before fire but there was no correlation with years after that. Thus, other factors excluding climate such as fire could be considered as the change reasons.

In order to investigate the vegetative properties of Juniperus excelsa M.Bieb in relation to soil and physiographic factors, Ilan site in Qazvin province was selected. First, map of land units was produced by overlaying of slope, elevation and geographical aspects maps. Inventory of vegetative characteristics such as density, DBH, height, number of trees with single trunk, number of trees with non-symmetrical canopy, canopy cover (%), canopy diameter and seedling density was performed in every land units by measuring 3 sample plots of 1600 m2 surface area. Three soil samples were taken from each land unit from 0-20 cm depth of soil and CaCo3, pH and bulk density were measured in lab. Results showed that except for trees with non-symmetrical canopy and trees height in different slope classes, other vegetative characteristics had significant difference among the land units, aspects, slopes and elevations at significant levels of 99 and 95 percent. Also, there is a significant correlation between number of juniper seedling with physical and chemical characteristics of soil. Highest correlation was observed for lime percentage and number of juniper seedling (r=0.54). There were positive and significant correlation between number of shrub plant, number of juniper trees, basal area and forest canopy percentage with number of seedling. Highest correlation was observed for forest canopy percentage and number of juniper seedling (r=0.64). Therefore, the vegetative characteristics of Juniperus excelsa M.Bieb in the studied site have significant correlation with soil and physiographic factors.