Plantation of fast-growing species such as Poplar is one of the important methods for wood production in the countries with low natural forest areas.Physiological differences of POPULUS DELTOIDES clones planted through three decades in Shast Kalate research forest are unknown. Peroxidase enzyme in this research was used for clone separation as a biochemical marker that is sensitive to environmental alteration especially temperature and its direct participation in lignification process. Sampling was done from one year old seedlings of five clones and quantitative and qualitative activities of peroxidase during five months (September through May) were measured using Worthington and PAGE methods, respectively. The results showed that peroxidase quantitative activity and isoenzyme pattern of clones were different among the months which indicated the role of this enzyme in cold hardiness and lignification of the clones.

POPULUS DELTOIDES is an important species of Salicaceae family and is distributed in Northern America. This species has been cultured widely in Northern provinces of Iran during recent decades. Survival and growth response of P. DELTOIDES seedlings to flood stress was examined at three levels of: control, shallow flooded (3 cm) and deep flooded (16 cm) in a completely randomized design for 120 days. The experiment was set up under outdoor conditions at the campus of Natural Resources of Tarbiat Modares University, Noor, Iran. P. DELTOIDES survival in the control and the flooding groups did not differ statistically and was more than 90%. By increasing flooding depth, height growth decreased but there were no differences between shallow flooding and the control. Flooding produced adventitious roots and with increasing flooding depth, adventitious root biomass enhanced. On the other hand, flooding decreased collar diameter growth, leaf area, specific leaf area, root length, root biomass, and total dry biomass of seedlings. Overall, the results showed that P. DELTOIDES was tolerant to flooding and can be used for restoration of plains exposure to periodic floods like plateau and riparian areas.

Propolis is a compound, produced by bees after collection of plant resin and mixing with beeswax. This rubbery material, due to its phenol and flavonoid, is one of the strongest natural materials with antibacterial properties which is used by bees to protect against external invades. The aim of this study is to investigate chemical analysis and antibacterial activity of poplar resin and propolis (produced by bees) extracts. In this study, the effect of ethanol and ethyl acetate extract of propolis and resin on three human pathogenic bacteria and two plant pathogenic bacteria have been investigated. Antibacterial activity of extracts was estimated by the well diffusion method. The extract compounds were qualitatively investigated. Results showed that, ethanol and ethyl acetate extracts of propolis and resin have antibacterial activity against plant and human pathogenic bacteria, however, antimicrobial effect of resin extract was higher than propolis extract. On the other sides, Plant pathogenic bacteria showed more sensitivity than human pathogenic bacteria to extracts. This is the first report of antibacterial effect of resin and propolis extract of poplar on plant pathogenic bacteria in Iran.

Parts of artificial forest with 10 hectars area were selected in northern forests of Iran. This forest were estabilished in two forms (pure and mixed stands) with POPULUS delta ides in 1987.20 plots were selected for consideration (10 plots in each stand). The diameter at breast height and height of trees, length and diameter of crown, healthy, vitality, volume and growth of trees and soil in all plots were considered. 12 trees (6 trees in each stand) were cut for wood physical and chemical analysing. The results are following:Thickness of liffer layer was more in pure POPULUS stand. The situations of soil in two stands were similar. The growth of trees was more in pure POPULUS stand. The quality of trees in pure stand was better than mixed stand. The fiber lumen was more in wood of pure stand, therefore, the burst and tensil resistence and breaking length in this stand was more than mixed stand. The wood density in mixed stand greater than pure stand. As the percent of lignin and extraction material in pure stand is less and its cellulos is more than mixed stand, therefore pure stand is more suitable for pulpwood. As a whole, because the mixed stand having variety production resistence against pestes and fungi and more uses of soil and space better than pure stand, but the base of different conditions of climate, site and uses of wood the selection of pure or mixed stands is different. In this area the pure stands of POPULUS in some objects especial for pulpwood more better than mixed stands.

In order to develop somatic embryogenesis for genetic manipulation process of POPULUS DELTOIDES Bartrex Marsh eastern, isolated leaf disk explants were cultured on MS medium supplemented with 2,4-D (2,4-dichlorophenoxyacetic acid), BA(benzyladenine) and glutamine. High number of somatic embryos formed on both the midveins and secondary veins. MS medium containing 2 mg/l 2,4-D and 0.1 mg/l BA with 20 J.LM glutamine showed highest number of globular-shaped embryo (11.6). Most of the embryogenic calli were formed on the cut edges of the leaf disks in MS medium containing 5 mg/12,4-D and 0.1 mg/1 BA for all glutamine concentrations. MS plant regeneration media supplemented with 2 mg/l BA and 0.1 mg/1 NAA (Naphtalene Accetic Acid) produced high percentage (72.5%) of plantlets on callused leaf disks explants. Rooted plantlets in WPM basal medium were successfully acclimatized on soil medium (1:1:1 peat, perlit and vermiculite) and transferred to the field.

Threes, six and 12 years old sample trees of Populos DELTOIDES 77.51 were randomly selected and felled at the safrabasteh research station located in Gilan province. Sample tree transferred to the Alborz research center- Karaj for Laboratory studies; The Laboratory studies included determination of physical, anatomical and chemical composition of revealed that with increasing trees age, fiber length and fiber diameter increased. There was significant differences among three ages studied at I percent probability.

Poplar collection project was carried out in frame of the national project for gathering native and exotic poplar clones and establishing of selection nursery, using 57 different species and clones in year 1984 in the Alborz research center, Karaj. Five seedlings from each clone (two years old) were planted in lines with 5m×8m spacing. During the study years, more new clones from five poplar sections were gradually added to the previous ones. Therefore, the total number of poplars in the collection became to 69 samples. Irrigation, weed control and branch pruning have been done during growing seasons. Phenological studies of different Poplar clones have been done from mid December to mid February, every year. In the first three months of growing season, phenological phenomena have been observed and recorded by binocular, twice a week and during the other months it has been done once a week. In this paper, we revealed information of phenological study for 28 POPULUS euramericana and POPULUS DELTOIDES clones. Results showed that vital activity in poplar trees starts between late February until late April and ends up between late October until middle of December. Vital phenomena (blooming, flushing, maturity and dispersal of seeds and leaf fall) have appeared in different times among different clones and different years depending on air temperature. By checking of blooming and flushing dates during the study period we can conclude that the beginning of the vital activities tends from April to March and from March to February. This means that spring begins sooner in the last years of the experiment. In the other word, the length of the growth season during these years has been increased by several days in Kkaraj climatic conditions.

Background and objectives: The possibility of using agricultural lignocellulosic waste as a complementary raw material for the production of wood composite products can have a good economic justification. This will be possible if the manufactured product has the desired and standard quality, however, considering that the type of wood material can have a determining effect on the physical and mechanical properties of the final product, therefore, conducting laboratory and research studies in order to recommend A raw material is essential for consumption in industry. The use of agricultural lignocellulosic waste in wood composite products industries has been the subject of various research activities in different parts of the world in recent years. In this research, in order to improve the mechanical and physical properties of wood-plastic, nanoclay particles have been used as reinforcements and corncob wastes have been used with poplar wood.Methodology: The amount of polypropylene and combination of materials were 60 wt% and 40 wt% respectively. The Nano-clay was added in three levels 0, 2 and 4 wt% and the amount of coupling agent was fixed and set to 2 wt% for all treatments. The control samples were made using poly propylene material. Results: The results showed that the tensile and flexural strengths were increased by the addition 25 corncob and 75 poplar wt% particles. For tensile and flexural modulus, adding 2 wt% of nano-clay led to an increase in strength and modulus but there was a decrease when 4 wt% nano-clay was used. The impact strength increased by adding nano-clayConclusion: According to the mechanical and physical properties of all the treatments, the samples which were made of 25 corncob and 75 poplar wt% particle with 2 wt% of Nano-clay had better results compared to other samples.

Increasing carbon storage in forests is the goal of sustainable management, in recent years, it has been recognized as one of the important tools in mitigating the impact of climate change. Carbon trading is one of the market-based tools as a cost-effective and convenient way to climate change and environmental issues. The aim of this study is to determine the economic value of carbon in poplar plantation. Carbon content was measured in the plantation of POPULUS DELTOIDES and adjusted carbon price was determined using the non-stationary regression model. Net present value of carbon was calculated and finally sensitivity analysis of price and carbon interest rate were performed. Results show the plantation stock was 180. 2 m3/ha (57. 6 t/ha) and carbon content was 32. 2 t/ha at age 36 years. Net Present Value calculated at different ages and the sensitivity analysis showed that the net present value increased with increasing price and interest rate.

In this study, in order to investigate the effect of seasonal changes on some physiological and biochemical characteristics of POPULUS deltoids, leaf and root samples were collected with four replicates in spring, summer, and autumn in Langroud region in 2010. Results showed that during the summer, with an increase in temperature and decrease in relative humidity, the amounts of chlorophyll a and b, soluble sugars, and activity of catalase and polyphenol oxidase enzymes in leaves were significantly increased compared to the spring leaves, whereas increment in the activity of peroxidase enzyme was not significant. On the other hand, the amount of soluble sugars, activity of catalase and peroxidase enzymes in roots did not show any significant change in the summer compared to the spring roots. However, the activity of polyphenol oxidase enzyme increased significantly. The amount of proline in leaves and roots increased significantly in the spring when the temperature was minimum compared to the other two seasons. The amount of Fe, Cu, and Mn increased significantly both in leaves and roots in spring compared to the other two seasons. Accumulation of Fe and Mn in roots was higher than those of leaves and the accumulation of Cu in leaves was higher than that of the roots in spring and summer.