Iranian Journal of Forest and Poplar Research
Year:2002 | Volume:10 | Issue:1|Papers Count:6

Norway spruce has been planted on a wide range of world it is generally pyramidal in shape and can grow to 40 m in height and to 1 - 1.5m in diameter.Norway spruce has a poor reputation for wind firmness. it is a shallow rooting species on sites with a high fluctuating ground water table or on soils where the effective rooting depth is limted.This study was carried out during 2001 - 2002 in four sites of Guilan Forests .These sites were Aroston, Rec, Picehson and Shenrud. The primary distance between the trees was 2x2 m.The stands age in Shenrud and the other sites was 17 and 27 years, respectively.The investigated growth parameters were: Survival %, mean height, mean D. B. H., density per hectar, basal area per hectar, annual growth rate of diameter, annual growth rate of height, dominant height, number of diameter classes per hectar, annual growth rate of tree volume, stand volume per hectar, volume table (tarif), form factor (f), relationship between quantitative parameters (diameter to height and diameter to volume) and stand qualitative parameters (natural pruning, stem condition and branch angle). The wood mechanical characteristics (density and fibre length) and the stand pests and diseases were investigated as well. In order to study the effects of Picea plantation on soil characteristics, soil sampling has been done inside and outside the plantations. Overall, the soil samples were tested physicaly and chemicaly and the data of the two sites were compared. The results showed that Aroston site was the best one due to its greatest survival (70%), growth rate (basal area: 37 m2 , Volume: 301.25 m3/ha, annual volume growth: 11.1 m3/ha)and wood quality (trachied length: 2.89 mm and specific gravity: 0.36 g/cm3).

Banah is an Iranian endemic pistachio species located throughout the western, southern and central rocky highlands. Alternate bearing along with parthenocarp fruit production is a common specification of Pistacia species such as Banah. Normally, the rate of male to female individuals is 30-50%. In this study, open pollinated flower samples were collected at anthesis, four and seven weeks after. Flower and fruit samples were prepared to die with aniline blue and tolueden blue 0, respectively. Seven-week-old ovules were empty (parthenocarp) grown up to fruit harvest periode. 17% of abnormal fruits were undertaken a sort of either disable embryo or abnormal andosperm leading to empty or half seeded fruits. A most conspicuous abortion was related to strile florets (50%) located in lower part of inflorescence branchlets. Many of strile florets had no embryo sac or an empty one and/or an aborted embryo sac. Thus, about 3% of Banah pistils were normally fertilized and reached to mature stage as a viable fruit. In this research the pollen-pistil interaction in relation to abnormal fruit and flowers ending to abortion or abscission were studied.

Because there is not enough information on the percentage of seed germination of native broad-leaved species of Caspian Forests of Iran, seed sowing is usually done with extra density. For this reason, most of the produced seedlings are thin and have low height and diameter growth rate. In case of sowing seeds with low density, the seedling production is not profitable due to few numbers of seedlings per area unit of nursery. The current trial was conducted, using Randomized Complete Blocks Design with three replicates for each species to obtain an ideal density of seed sowing and increase seedlings quality.Four species were tested including Quereus eastaneifolia, Tilia begonifolia, Aeer velutinum and Fraxinus excelsior. Four seed mass treatments per squar meter of nursery were applied for each species which differ for different species. The plot area was three squar meters. After measuring weight of 100 seeds of each species, the seed mass of each treatment was sawn inside of the plots along five rows. Only the seedlings grown on the three middle rows were considered and studied, leaving the first and the last rows as bufer lines. Space between the rows and between the plots was 20 and 30 cm, respectively. Two seed sowing seasons were planned: spring and autumn. According to the results achieved, autumn was the best, so all of the measurements and evaluations were made in that season. The differences between the seed density treatments were not significant, for all species. Best seed density for Q. eastaneifolia, T begonifolia, A. velutinum and F. excelsior was 500, 100,40 and 50 g/cm2, respectively.

The purpose of this research was to select the suitable poplar clones at seedling stage among 65 clones in a period of five years. The following parameters were investigated: Height and growth diameters, percentage of survival, percentage of cutting spruted in different time of planting, the effects of cutting at the base of shoots on the growth of side tillers, shoot growth rate at 1/1 (one year root and one year shoot), uniformity of seedling growth and major pests and diseases and the rate of sensitivity of each clones. The results demonstrate that at the end of growth period, percentage of survival for Populus alba was lower than the other species. This was due to decrease of root forming and low percentage sprouting of cuttings in Populus alba.Populus alba and section Tacamahaca were less sensitive to adverse environmental conditions (specially moisture) than the other species. The study indicated that Populus deltoides species had the highest growth rate and Populus alba had the least growth when "Cutting at the base of the shoot" technique was applied.Among different group of Poplars studied, section Tacamahaca was more susceptible to pests and diseases (specially wood bore insects) than the other groups, and P.alba from leuce section was among the group having the highest resistance to wood borer attack. Finally, it should be stated that among the clone of each group, there were more differences than what we have expected.