Iranian Journal of Forest and Poplar Research
Year:2008 | Volume:16 | Issue:2 (32)|Papers Count:20

Yew is one of 4 conifer species which is distributed and endangered in the northern forest of Iran. In order to study the effect of cutting and bed soil in nursery on success of vegetative propagation of Yew, two different kinds of cuttings (one and two years twigs) and four different soils (loam, sand, sandy loam and mixed soil) were used. A total of 540 cuttings, containing 15 cuttings in each treatment were studied. Results showed that there was a significant difference between treatments at level of 5%. The highest rate of rooted cuttings (82.2%) was observed within one year old woody cuttings in pure sand bed, while the lowest rate (13.3%) was observed within older cutting in loam bed.

In order to investigate the effect of KIBA and kind of cutting on rooting of Yew (Taxus baccata), 4 different levels of KIBA (0, 25, 50 and 75 mg/L) and 3 different kinds of cutting (upper, middle and lower) were studied. Results showed that the highest rate of rooting was observed by application of 75mg/1 KIBA. Also the upper cuttings showed the highest rate of rooting and survival after 23 weeks.

In this study growth of 15 year-old trees of Pinus eldarica Medw. were investigated in two areas irrigated by municipal effluent and good water in south Tehran. For this purpose four sample plots (30x30 m) were systematic-randomly chosen in both areas. The results showed that diameter at breast height (d.b.h.), total height, crown length, average crown diameter, basal area and volume of Pinus eldarica Medw. trees and the concentration of nutrient elements (N, P, K, Ca, Mg) of soil in area irrigatedby municipal effluent were significantly(P <0.01) greater than by good water. It might be concluded that the municipal effluent could be utilized for irrigation trees at afforestation.

Poplars are fast-growing species that were planted pure in the past. Mixed plantations of poplar with nitrogen fixing species have been recommended recently to increase the soil fertility. In this study, American poplar (Populus deltoids 77/51) has been planted with different mixture ratios with Caucasian Alder (Alnus subcordata) in randomized complete blocks with four replications in Chamestan research station, Mazandaran province, northern Iran. For further comparisons, pure stands of poplar and alder were also added to the treatment design. The plantation spacing was 4x4m. Results after 7 years showed that survival rate of poplar were greater than alder, in general. The highest rate of poplar survival was observed in the treatment of 50% poplar + 50% alder. The differences among treatments were statistically significant. The highest diameter increment was measured within poplars in the treatment of 33% poplar + 67% alder and the least in the pure poplar stand. The highest total height was measured within poplars in the treatment of 67% poplar + 33% alder. The highest volume of individuals trees were measured within poplars in the mixture of 33% poplar + 67% alder, while the highest tree volume of alder was obtained within the alder pure stand. The amount of soil nitrogen was significantly higher in the pure alder stand and mixture of 33% poplar + 67% alder, than in the soil of other treatments.

The Chaharzebar forests with 3000 ha area is located in a mountain section, 34 kIn S.W. of Kerrnanshah province in Zagros mountains. The collected plants in this area include 161 species and subspecies which belong to 124 genera and 40 families. The richest families are Poaceae, Papilionaceae, Asteraceae, Lamiaceae and Apiaceae respectively.Therophytes are the most frequent biological type, and followed by Remicryptophytes, Phanerophytes and Chamaephytes. In chorotype view, most of plants belong to Irano-Touranian region. The study of plant communities was based on Braun-Blanquet method. 28 reIeves were taken in different habitats and analyzed by Anaphyto software based on A.F.C and CAR methods. Totally, one association, Astragalo tortousi - Quercetum persicae, and two subassociations, acantholimono blakelockii-festucetosum ovinae and gundelietosum tournefortii were recognized. The recognized subassociations are different by exposure, slope and the quantity of organic matter of the soil.

In order to investigate the adaptation potential of Taxodiaceae species at Chamestan plain of northern Iran, 3 species (Cryptomeria japonica, Sequoia sempervirens and Taxodium distichum) were planted within an area of 1600 m2 in spacing of 4x4m. At the age of 24 the survival rate and some quantitative (dbh, height, annual increment and volume) characteristics were studied. The highest survival rate was observed in the Cryptomeria stand (98%) and the least survival in bald Cypress stand (60%). The results showed that the highest dbh and height of trees belong to redwood stand with 41.9cm and 19.95m, respectively. The lowest dbh and height were measured in Criptomeria stand with 23.3cm and l5.95m, respectively. In general, one can conclude that all 3 species could be considered as promising species.

In order to identify the effect of shelter wood logging on the species diversity in each stages performance, a study was conducted at the Loveh forest, east of Golestan province. Totally, 117 plots with 60x60m were set down with systematic cluster sampling method at the study area. Diameter at breast height (DBH) of trees and species were assessed in each plot. In this study three managed stands including 20 years practiced stands (shelter wood system), 40 years practiced stands (shelter wood system), and improvement stand as well as one unmanaged stand were compared based on Shannon-Wiener, Smith-Wilson and richness indices. The results of analysis of variances showed that difference among four stands were significant (p<0.05) and highest values of Smith-Wilson and lowest value of Shanon- Wiener indices were observed in the natural stands. These differences may be referring to logging and opening crown cover. These results showed that the species diversity was decreased where shelter wood system was applied. The low values of Shannon-Wiener indices and Smith-Wilson indices in 40 years practiced stands compared to 20 years practiced stands confirmed the results.

The objective of this study was to find out the most suitable date of seed sowing in respect to quantitative and qualitative growth of Pinus brutia and Cupressus sempervirens var. horizontalis seedlings in forest nursery from September 2003 to September 2005. In respect to quantitative parameters of both studied species (mean collar diameter, mean height), the sowing date in autumn was better than the spring (P<0.01). In respect to qualitative parameters and survival of seedlings there was no significant difference between the sowing dates for Pinus brutia. However, for Cypress the autumn sowing date was better than spring (P<0.01).

Effect of edaphic and geomorphologic factors on the growth promotion or restriction of the planted seedlings of Cupressus sempervirens var. horizontalis Mill., Cupressus sempervirens var. arizonica Greene., Pinus brutia Elwes Henry., Pinus eldarica Medw., Ailanthus glandulosa Desff., Robinia pesudoacacia L., Quercus brantii var. persica Zohary., Fraxinus rotundifolia Mill. and Elaeagnus angustifolia L. was studied in a pilot project at the Kamfirooz research station in Fars province. The statistical design was completely randomized block with 3 replications. As in a previous 10-years study in the same area with the same species, significant differences had been observed among replications, we designed this problem oriented study to pinpoint the edaphic and geomorphologic factors, which might have influenced the performance of these species. Soil map units (SMU) were differentiated on the basis of topographical and geomorphological aspects. In each SMU, morphological characteristics of soil profiles (depth to the lithic contact) were studied, and three units A, Band C wee separated. Subunits were selected on the basis of factors that prohibit or improve plant growth. It was hypothesized that the presence or absence and the degree of cementation of marl stratum in the subsoil, and the degree of slope and amount of stones in the rooting zone, were the growth limiting factors. Moreover, soil physical and chemical characteristics were considered as the effective growth-modifying factors. The growth was evaluated visually and numerically from I (the best) to 5 (the worst). Also the 4 years average of survival rates in each replication were used to evaluated the relationship between plant growths and soil factors. We strongly believe that the morphology followed in our study is superior to the currently used evaluation techniques, as it takes into account those factors which heavily affect plant growth in our area.

Wood transportation from cutting areas to saw mills includes two phases; 1) transport of logs from cutting areas to road side (primary transportation) by skidder and 2) wood hauling by logging tracks from road side to saw mills (second transportation). The goal of the current study was to evaluate the total time skidding and wood transportation and production rate of skidder and logging trucks and effective factors of logging operation in Nekachoub area, north of Iran. In this study, based on data from continuous time studies for different phases, 45 and 60 turns were recorded on skidder and logging trucks, respectively. Collected data were analyzed by mathematical model of skidding time by TAF skidder, including winching distances, slope, number and volume of logs and hauling time, hauling distances, number and volume of logs. The results showed that submitted models were valid for skidding and hauling times. Thus, logging cost would be calculated. In this research, production rate for TAF skidder, wood transportation by logging trucks from road side (landing in forest) to saw mill depot by truck were 10.26 m3/hr and 5.79 m31hr, respectively.

The necessity of successful and practical planning in urban forestry and green space of city, in addition to costs and financial sources, is knowing the present situation and potential of considered area from its kind of requirement and ability in growing plants. In this study, IKONOS images and aerial photos were used to get information about the situation of city green space and calculate average of green space per person in the North West of Tehran, third region and some part of second region of municipality, for 538 hectare. Therefore, satellite images were interpreted by automatic digital analysis with maximum likelihood algorithm after necessary preprocessing. Meanwhile, the aerial photos after digitizing and geometric correction were used as ground-truth in classification. For this purpose a dot grid with 4371 points, located in 100 square meter cluster, overlaid on the aerial photos. Then it was determined that each dot belonged to which class. The distances of clusters from each other were 100x 100m and the distance of the dots in each cluster was 5x5m. The results were compared with the results of automatic classification of satellite images, and the error matrix was made. Overall accuracy of classification was 97%. The area was divided in 45 zones according to the boundaries the statistic center of Iran and the average of green space was calculated regarding to the number of population and space of green area in each zone. Then the bare lands were detected and measured as a maximum increasable potential to green space. The results represented that the average of green space per person is 14 square meters in the study area that it's about 20% of whole of it, and the range of it, is between 3/9-28/9 square meters per person that varies in different zones. Finally, the bare lands were ranked in allocating to green area via overlaying the maps of empty places and average of green space.

The aim of the study was to determine the accumulation of heavy metals (Cr and Ni) in different layers of soil, leaves and fruits of Olea europaea. In this investigation, irrigation of olive trees were done with both water of well (control) and sewage, for seven years in Rey town, south of Tehran. In each treatment (well water and municipal effluent), three samples were selected systematic randomly. In each sample, leaves and fruits of olive trees and soil (from 0-15, 15-30 and 30-60 cm depths), were collected for analyses in three replications. Samples were analyzed with standard methods and used atomic absorption based on flame (PU9400X). For comparison of concentrations of heavy metals in layers of soil, leaves and fruits and in order to normalizing of data, independent sample t-test was used. Results of this study show that irrigation with municipal effluent increase concentration of Ni and Cr in soil. Concentration of Ni and Cr were statistically greater in leaves of trees irrigated with municipal effluent than those of the leaves of trees irrigated with well water. There was no significant difference in spite of accumulation of heavy metals (Ni and Cr) in Olive fruits.

Iran is located in the North Temperate Zone from 25 to 40 degrees latitude and 44 to 63 degrees longitude, with a total area of approximately 1,650,000 Km2. A 50% of total lands area is covered with high mountain ranges. Elevations range from 26 meters below sea level on the shores of the Caspian Sea to 5860 meters above sea level at the pick of the Mt. Damavand. Drought or water deficiency is one of the most critical climatic factors in Iran. About 50% of Iran can be classified as arid or semi-arid zones. Climate parameters, particularly precipitation varies significantly in different parts of the country. There is not a good annual rainfall distribution in most regions of Iran, which limits the plant development and growth. Not only high temperature in southern, central and lowlands of Iran is a limiting factor, but also low temperature in northern, western and highlands is another limiting factor too. The Caspian region receives the largest part of the country's precipitation while the central desert (Dasht-e-Lut) is faced with permanent drought. Forest ecological zones in Iran could be categorized as: a) North, Caspian forest, b) West, Zagros forest, c) North West, Arasbaran forest, d) South, Subtropical forest in Persian Gulf areas, and e) Central, Scattering forests. Some of the main tree species of Caspian forests: Fagus orientalis, Carpinus betulus, Acer velutinum, Quercus castaneifolia, Fraxinus excelsior. In this study, whole forest areas in southern part of Caspian Sea were monitored by study on vegetation map and visiting field. Three points representing major part of Hyrcanian Forests were selected from wet part in west to drier part in east. Four meteorological stations data used for investigation. Most of climatic factors including maximum, minimum and mean annual temperature; daily and annual precipitations were investigated. Mainly trends of mean annual temperature and annual precipitations were used for conclusion. It can clearly be concluded that during last half century climate in forest area in Caspian region become armer. Precipitation trends especially in Anzali station that has highest precipitation records in Iran and also in Gorgan station have decreased. Precipitation trends in Rasht and Baboulsar stations have shown positive change. During last 49 years in Rasht station mean annual temperature increased about 1.28 °C and even its minimum temperature shows 2.45°C increases. Increase mean annual temperature in Baboulsar station in last 54 years is about 1.44°C and its minimum temperature shows 1.80 °C increases. Decrease of annual precipitation in Anzali station during last 54 years of records is about 409.4 mm and amount of decrease of precipitation for the period of last 53 years in Gorgan station is about 55.6 mm. Distribution of plants are directly depends upon temperature and precipitation conditions in each climatic zone. Generally with increasing about 100 meter of elevation amount of temperature will decrease by one degree of centigrade. In study zones especially in Gilan and Gorgan areas temperatures shown more than one degree increases and main species of vegetation cover moved upward about 100 meters. All data statistically were analyzed.

By comparing the pattern of narrow and width rings among the trees in one area, the exact year of each rings could be determine. This is the base of Dendrochronology. In this study, according to the important role of Juniper (Juniperus polycarpos) trees, an investigation have been done on variation of tree rings in three sites of Iran; Lain (Khorasan), Firouzkouh (Tehran) and Zanjan. 15 trees have been cored in each sites and ring width of each core was measured. After crossdating and standardization, 3 ring width chronologies were prepared and compared with climate data. Lain's trees were older than the others and Zanjan was the worst site. In many cases, the chronologies had similarities, especially between Lain and Zanjan and in extreme years like 1902, 1917, 1961 and 1975. There were significant correlations between tree ring width and temperature and precipitation in the study areas. Some of the most important ones were the positive effect of precipitation during autumn and winter period before and during the current growing season. The temperature had mostly negative effect on juniper trees but the temperature during September had mostly positive effect concerning the improvement of latewood cell's expansion. The results showed that the Juniper trees are appropriate trees in Iran for studying dendroclimatology.