Iranian Journal of Forest and Poplar Research
Year:2003 | Volume:11 | Issue:9|Papers Count:5

Poplar cultivation are the most important sources of wood production in the country and the lands along Zanjan- Rood river are one the best sites for poplar plantation. The plantation consists mostly of two species: P. nigracv. "pubescens" and P. alba cv. "shirazi".After selecting some sample from 98 poplar plantation sites located between Kooshkan and Nickpay villages of west Zanjan city, the tree samples were fell down, cut, logged and measurd. The data were analyzed, using the SPSS software. As a result, the most appropriate equations were calculated and defined for the tree volume tables. Overall, three volume tables ewre developed separately for each species from the equations. In addition, weight and volum of some poplar loges were calculated and their volume coefficient were estimated. The results showed that: 1- In diameters and heights equal to 50 cm and 25 m respectively, the volume of P.alba and P. nigra will be 2.5 and 2 cubic meters, respectively.2- Based on all the growth variables (diameter, height, volum and qualitative Characteristics ),p.alba cultivars were the best.3- Because P.alba cultivars have woods with better quality than P.nigracultivars, their economical values are greater than P. nigra culivars as well.

The aim of this research was to select the suitable poplar clones among 52 clones at seedling stage, after four year period. The clones characteristics during different age stages were studied, including, seedling height and diameter growth, survival percentage of one year old seedlings at the end of growth period and seedlings growth at different years. The cutting method was used to propagate the poplar seedlings at 30 and 120 cm columns and rows planting distance, respectively. One year old seedlings (1/1) were produced for the investigation at the first growth period. Number of clones of the species P. nigra, P. alba, P. euramericana and P. deltoides was 27, 14, 7 and 4, respectively. The one year old seedlings (1/1) characteristics at three growth periods were used for further seedling production and poplar plantation with the aim of wood production and reduction of wood import. The SPSS software was applied for data statistical analysis, particularly Duncan test. The results showed that survival percentage of P. alba was the least in comparison with the other species whereas the diameter growth of P. deltoides and P. euramericana and height growth of P. deltoides and P. nigra were the greatest in comparison to the other species. There was significant difference of height growth between the species at different years.

This research was done at two different altitude levels of two northern provinces (Gilan & Mazandaran). The altitude levels for Mazandran provience were 80 and 1100 meter and for Gilan providence were 10, 450, 700-1000 and 1000-2030 meter above sea level (coastal, low, moderate and high level, respectively). After studying the enviromental parameters and writing down their data, the individual trees of Fraxinus excelsior at each sample plot were selected. The environmental studies and their ecological factors indicated that the most of Fraxinus excelsior seeds were hallow due to destroying of natural forest ecosystems. Natural regeneration was not found because of overgrazing by livestocks. Sampling was done from male and female from flower spruting to seed ripening stages, monthly. The investigation was carried out for 3 consecutive years (1996-1998). The samples were extracted then qualitative and quantitative alterations of proteins and enzyme (peroxidase) were studied by polyacrylamide gel electrophoresis (PAGE) and spectrophotometric methods, respectively. Alterations of Na +, Ca2+ , K+ were measured by flamephotometric method. Results indicated qualitative and quantitative alterations of proteins, enzyme and peroxidase is enzymes during sampling. Sprouts had the minimum izoenzymatic bands, peroxidase activity and protein content. During the Thir and Mordad months proteins and peroxidase activity were maximum qualitatively and quantitatively. In rippened seeds peroxidase activity was minimum and izoenzymes were high molecular weight ones. The number of izoenzymes was minimum at that time. Quantitative alteration of proteins was almost similar to the peroxidase alteration. During seed development contents of Na+, K+ and Ca2+ changed regularly. Alteration of sodium was more than K+ and Ca2+. This indicated that this element had an important role in the metabolic development of Fraxinus excelsior seeds. Germination of seeds were studied under different conditions such as seasonal sampling (beging and end of Shahrivar and Mehr months), storage at -8 and +4 centigrade degree for 15 days and nutrional treatments (distilled water and hydrogen peroxide). The best treatments were sampling at the end of Shahrivar (before seed color change), storage at -8 centigrade degree for 15 days and hydrogen peroxide treatment. Percent of germination increased from 0 (in control) to %100 in treated seeds.

In this research, areas that covered with Amygdalus spp. Were distinguished and marked on maps with 1: 50000 scale. Based on three ecological factors such as: elevation, geographical aspects and geological formations. These areas were divided to 126 ecological units. Overall, after deleting the similar units, 57 units were identified and used for tree and site sampling.The stratified sampling method was used. Finaly 126 original plots and 252 sub, plots (200 * 300 m.) were randomly allocatedted to each ecological unit. The following site and tree parameters and characteristics were studied and measured: site altitude, aspect, gradient, geology, soil type and depth, climate and tree height, canopy diameter. height and area percentage, collar diameter of the tallest stem, density and regeneration.Results show that there are four species and two subspecies of Amygdalus in Ilam province, with total area of 118802 hectars. The species A. lycioides and A.scoparia are growing in four climates: moderate dry, moderate semi dry , cold semi dry and cold semi humid. A. orientalis is growing in two climates: cold semi humid. And upper elevations The range of elevation for the species A.scoparia, A.lycioides and A. orientalis is 400 , 1700, 600 , 1900, and 1300 - 2500 m. above sea level, respectively.