Iranian Journal of Forest and Poplar Research
Year:2006 | Volume:14 | Issue:3 (25)|Papers Count:10

In order to select and introduce the promissing clones of Populus deltoids and P. euramericana, 18 clones were planted 4×4 m in two research stations of Kermanshah province. The statistical design of the experiment was randomized complete block with three replicates. At the end of each growing season, diameter at breast height and height of trees were measured. Moreover, at the last year other factors such as collar diameter, media diameter, top diameter and weight of trees were measured as well. The results after 8 years showed that Populus euramericana 488, P. euramericana 214, P. euramericana 92/40, P. deltoides 77/51, P. euramericana 455 and P. euramericana 561/41 are the most promissing clones. The mean diameter of clones varied between 22. 3 and 26. 7 cm, mean height between 18. 2 and 20m and mean volume increment varied between 27 and 39 m3ha-1y-1.

Gall oak (Quercus infectoria Oliv.) is one of rare species that is only presence in the northwestern part of Zagros mountains. This research aims at studying site demands and some quantitative and qualitative characteristics of Qurecus infectoria. For this purpose, the distribution area of this species was studied in Lorestan province in western Iran. Twenty four sample plots, each 1000 m2, were established in 3 land forms (ridge, valley and slope), in 4 aspects (north, east south and west) and in 2 altitudes level (1200- 1600 and 1600-2000 m.a.s.l.). Also the chemical and physical properties of soil in the sample plots were studied. The results showed that the surface of distribution area of Gall oak is 5751 ha and its extended from 1200 to 2400 m.a.s.l. The soil of oak sites were usually light (loam) to heavy (clay) with a pH between 7.4 and 8.0. Organic matter is realtively good and EC is insignificant in the studied site soils. In general, slopes and vallies with north aspect in altitude between 1200 and 1600 m.a.s.l. are suitable sites of this oak spieces. The highest oak tress were observed on north faced vallies (7.7m), the longest trunk length (3.2 m), the widest crown diameter and also the highest proportion of oak trees with good quality (75%) were assessed all observed on north faced slopes.

Although Zagros forests are not important from wood production aspect, but in terms of environmental and ecological aspects, by products, soil and water conservation as well as shelters for wildlife are very important and play undeniable role in sustaining ecosystem and the economy of inhabitants. These forests are habitat of an important tree species, namely wild pistachio (Pistacia atlantica). This species has been exploited for its gum for a long time and lacks good regeneration due to the absence of seed producing stands. The possibility of rehabilitation of pistachio forests was studied through straight seed sowing and seedling planting to find the simplest and the most economic way of conserving these forests and to prevent further destruction. The research was carried out in a split plot statistical design with seed and seedling as the two main treatments and four sub-ordinate treatments such as common pitting, bowl pitting, furrow and banquette within Arsenjan site. During the period, germination, survival and growth of seedlings were recorded. In addition the presence of pests and diseases and the relation between climatic factors and the establishment and survival of seedlings were also examined. The results indicate that the rehabilitation of wild pistachio forests through seed/seedling plantation was not successful in Fars province due to several limiting factors, including low and uneven rainfall, the existence of a long dry period, high evaporation and moisture stress during growth season. The failure was more serious in seed sowing. Furthermore, cutting and severe pruning of parent trees, presence of livestock in the forest and wildlife grazing were other factors which threatened the establishment of new grown seedlings in the pistachio forest. However, the presence of seed producing trees, suitable crown cover and some shrubs and bushes as nursing plants would enhance the establishment and natural regeneration of pistachio forests provided that proper management and conservation of the forests are guaranteed.

Juniper is a beautiful evergreen conifer which is so useful for afforestation in arid and semi-arid areas. On one hand, propagation from seed of Juniperus excelsa is difficult, on the other hand, its natural regeneration for the natural ecosystem disturbance caused by destruction, is limited. Therefore, under the controlled greenhouse condition (MIST), it was proceeded to propagate the stem cuttings coco peat planting beds by plant growth regulators (IBA) at zero density and 3000, 4000 and 6000ppm. This experiment was conducted by a completely randomized block design with 4 blocks and 56 cuttings per block for each treatment. Results showed that there is a significant difference (p<0.05) between treatment 3 (IBA=400 ppm) and 1 (IBA=0 ppm). However, with increasing IBA amount from 4000 to 6000 ppm, the number of rooted cuttings is decreased.Therefore, the best treatment was coco peat planting bed using 4000 ppm IBA in April.

Construction of road netwok has a great important in every community. In one hand it improves the socio- economic development, on the other hand it has a great influence on destruction of natural resoures and soil erosion. In order to study the impact of road construction on forest, the Bazoft basin, asub-basin of Karoon watershed, was selected in Chahar mahal and Bakhtiari province. For this purpose, the length of all roads and the width of the destructed area were measured. Besides, the road plan in combination with slope, direction, geology and forest typology information’s was prepared using GIS. Results indicated that 661.08 ha of natural resources area was destructed by road construction, which contains 420.19 ha of forests, 198.97 ha of rangelands and 41.92 ha of agricultural lands. A total of 101 cases of landslide was assessed along the road network in the studied region. In other words, 6735m of road length (3.8%) has been moved because of landslide.

Projecting, rapid evaluating of routes and considering of different multiple factors in routing have been able using GIS capability and information-simultaneous management. This study accomplished to determine proper method for forecasting traces of mountain, forest, recreational regions and forest remains roads, in Sorkhab watershed, Khorram Abad. Concerning to environmental principals and network topology of forest roads, affecting factors in road tracing were studied after gathering of data and necessary maps. The interested maps including slope, landslide hazard, future land use, distance to village regions, recreational, and holly places were prepared as raster format using GIS. With concerning of importance of their categories, the maps were classified with range of 1 to 9. Using Analytical Hierarchy Process (AHP) method, the maps were weighted with regard to mentioned affecting factors. By overlaying of the weighted maps using GIS, the suitable regions map was prepared for tracing. The forest routes were automatically projected using PEGGER program implemented with ARCVIEW software. The TIN Digital Elevation Model was generated using 1:25000 digitized maps. The new 20 meters intervals contours were again produced from digital elevation model. Necessary layers including route location suitable regions map, streams, village regions, recreational and future land use imported to determine the routes. Regarding to kinds of roads the desired grades were inserted in PEGGER program. The various traces between two points were rapidly predicted and suitable routes were selected after valuation. Besides of road tracing in regions with low expenses for road making, results showed that using this method could prepare the feasible road network for interested area and important land uses such as forest and tourism areas. In the other hand, with consideration of present data in current condition such as digitized maps in this study, introduced method is an appropriate method for forecasting of preliminary route of mountain and forest roads in extensive scale so that this method can be replaced with the traditional methods in Iran.

Plant associations determination can be considered as a master key for knowledge on stand evolution, dynamic and environmental factors relations. Therefore, this study was carried out to find out the relationship between plant associations and physiographical condition to assess the vegetation profile. The study site is located in Noshahr, Kheiroudkenar research forest. The vegetation was sampled by using Braun-Blanquet method and plant associations were determined on the basis of vegetation data analysis such as TWINSPAN and ordination analysis (i.e., DCA) methods. ARCGIS software was used to map the plant associations and physiographical situations and to study their relation. The results showed that six determined associations were: Parrotio-Carpinetum, Querco-Carpinetum, Alno–Fagetum, Rusco-Fagetum, Carpino-Fagetum and Fagetum orientalis. The distribution pattern of the plant associations in different physiographical condition indicated that all associations occurred in most slope and aspect classes. However, their spatial pattern in different altitude classes were not the same. Parrotio-Carpinetum was located at the altitude of 200-800 meters above sea level. Where as Querco-Carpinetum was occurred at 600-1400 m.a.s.l. and mainly in south and southwest orientations. The associations which were dominated by beech were located at 800-1600 m.a.s.l., in which mixed beech communities occupied more area.

Quercus brantii var. persica (oak manna tree) is a valuable tree species in forests of western Iran. This species has been adapted to rough conditions of its habitat such as extreme summer and winter, long drought period and high elevation. For determining physiological patterns and alteration related to the establishment of oak in this environment, the changes of total non- structural carbohydrates and amylase activity in oak trees were studied in a less manipulated habitat during an annual cycle. The amount of total non- structural carbohydrates and amylase activity were measured by enzymatic and electrophoresis (PAGE) methods. Results indicated that non- structural carbohydrates concentration (glucose, fructose and sucrose) in March (before bud burst) was more than January ones. After bud burst and leaf expansion, when photosynthetic activity was high and after the beginning of drought period the concentrations of glucose and fructose increased continuously to September. Contrariwise the amount of sucrose and starch decreased slowly during this period. After summer and with falling temperatures, the total non-structural carbohydrates increased in November. In January, the content of starch was very low but the level of soluble carbohydrates was high. Thus the energy supply for metabolic processes in trees is secured during cold and hard winter seasons. Total non-structural carbohydrates ranged from 18.5 to 37.25 mg gdm -1. Seasonal changes of a-amylases coincided considerably with changes of starch and glucose concentrations of oak manna trees during the investigation period.