Year:2006 | Volume:19 | Issue:3 (72 IN NATURAL RESOURCES)|Papers Count:12

The dowel, screw and metal corner are the joints that are used in different field of industries to a great extent. This present study has been done to find the best form of joints used in the wooden sheets (such as bookcase, cabinets) from the lateral shear strength point of view. The researched joints are dowel joints in 8 and 10 mm Diam. With smooth or spotted (corrugated) surfaces and those which are soaked with P.V.A. or U.F. resins as well as types of metal corners form and screws with or without resin; this way, we studied the strength of 20 different joints using GSA standards and T- samples. The results proved that screw joints showed the most lateral shear strength comparing to other kinds of joints. The results also indicated that the strength of the samples showed no significance difference between different types of screw joints; however, due to some economic privileges, we recommend screw joint No 5 without soaking in resin.

This research will discuss determination of preservation and recreational values in Sisangan Forest Park and measure of individual’s willingness to pay (WTP) for preservation and recreational benefits based on contingent valuation (CV) and dichotomous choice (DC). For measure of individual’s willingness to pay was used logit model and its estimation parameters are based on methods of maximum likelihood (ML). Results show that 81.7% and 78.8% individuals have willing to pay for preservation and recreational values forms the Sisangan Forest Park, respectively. The mean of willingness to pay for preservation annual value of this park is RLs 6365 per household and mean of willingness to pay for recreational annual value of this park is RLs 2477 per visit. The preservation and recreational annual values was estimated 5.8 and 2.5 million RLs/ha (666 US$/ha and 291 US$/ha) for Sisangan Forest Park, respectively. Also, results revealed that forest parks had considerable preservation and recreational values. Thus, these values provide enough justification for policy makers to maintain the quality of forest park, and avoid degrading forest resources.

Cupressus sempervirense is one of the most important species on the basis of low ecological needs and tolerance against winter dry and summer heat. It is very current in forest plantation in degraded ecosystems and dry and semi- dry shrub lands in Iran. It is an important species for urban green space. In this research the effect of various light treatments were considered on growth and quality of seedlings and amount of weeds. A complete randomized design with four replications was performed. At first 24 quadrates including 24 seedlings in per quadrate (in total 576 seedlings) were indicated. Six different light treatments including 0, 33%, 50%, 67% and 100% and one treatment including the seedlings under tree canopy with four replications were performed. Other situations of nursery including: Soil, irrigation and so was the current methods in nurseries and it was similar for all of treatments. Total height, vitality and survival were recorded in 9 times. The results showed, all of shade treatments causes increase of total height. The most and lowest amount of survival was in 33% and 100% light treatments respectively.

The Eucalyptus species are exotics in Iran, from Myrtaceae family and are planted widely in most countries for their fast growth, tolerant to poor soils and other excellent characteristics. Therefore, Eucalyptus seedling propagation is very important in Iran due to its role in extending forest plantation. Sexual and asexual propagation by seeds and cuttings causes problems due to high variable progenies and presence of rooting inhibitors in adult tissues, respectively. So, in vitro micropropagation techniques were used to prevent these problems. The aim of the study was to investigate the effects of growth regulators on shoot explants sampled from E. melliodora seedlings (internod segments).The experimental design was Randomized Complete Blocks (RCB) with nine treatments (BAP: 0.1, 9.6, 1.0 mgl-1 and 2ip: 0.5 and 0.6 mgl-1) and five replicates and five explants at each plot. The regenerated shoots were treated with GA3 (0.05 mgl-1), BAP and 2ip to increase their length growth. For rooting seven treatments of 2,4-D and NAA were applied at four concentrations (0, 0.1, 0.5 and 1.0 mgl-1) Although the effects of different growth regulators on regenerated shoot growth characteristics (length, number, weight and fresh shoots and bud numbers) were significant, but the effects of both growth regulators and GA3 were only significant on shoots length. The best treatments for explants shooting were: BAP+2ip (0.1, 0.5 mgl-1), BAP (0.1 mgl-1), BAP (0.6 mgl-1), 2ip (0.5 mgl-1) and 2ip (0.6 mgl-1), respectively. The best medium for rooting was the one without growth regulator where there was minimum callus and no aerial roots. Application of NAA concentration at 0.1 mgl-1 resulted in highest rooting. After climate hardening of the plantlets, they were transferred to soil and started a normal growth after a long period.

Madder is the biennial to triennial plant resistant to saltiness. The roots of madder provide us with one of the most reliable reddyes used for dyeing specially carpet fibers. It is one of the agricultural and industrial plants in the province that do not any economic study on present. Cultivation of madder at 2002-2003 was 413 hectar and production 2413 ton that value of production madder is 16 miliard rial. The investigation results show that profitability of madder per hectar is not only higher compared to other products but it is acceptable and satisfactory to farmers (17436188 rial per hectar, total revenue 56091875 and total cost 38655687 per hectar). Mean while marginal and total factor productivities were calculated through production function and the results showed that for each cost unit, madder produces 64 gross revenue units. In this research productivity of manure was more than other factors whith proves the significance of this factor. More over productivity of water was calculated to a limited extend and the results were indicative of wasting this vital substance in the region.

In order to study the genetic variation of wild service (Sorbus torminalis (L) Crantz) in the Sari forest of Mazandaran province, the seeds and leaves of 40 individual trees of two populations were collected. 7 characteristics of fruits and 13 characteristics of leaves were measured. Principle components analysis was used. Results showed that; the average, maximum and the minimum weight of fruits were 1.3, 1.72 and 0.88 gram, respectively. The most rate of length and width of lamina was 11.52 and 8.62 respectively. It has seen no correlation between the number of sound seeds and the weight of fruit. But there was positively significant correlation between fruits weight and sound seeds weight (p<0.05). About all seeds, fruit and tree characteristics, there was only significant and negatively correlation between trunk straightness and fruits weight (p<0.05). Also between leaf lateral incisions and tree seed double branching was negatively significant too (p<0.05). In principle components analysis, width, depth of lateral incisions and shape of leaf base has the most important role in first component and the number and weight of sound seed in second component. The genetic variation in these two populations was low .And it is influenced by unnatural factors such as humans and livestock. So it needs to be protected.

Pistacia atlantica subsp.mutica is a predominant and endemic species throughout the western open forest in Iran which seedlessness is a factor for limitation its regeneration. In this trial some of physiological aspects ending to seedlessness were studied. By reason of separation of male and female trees in this genus, incompatibility was major problem for seed production. So ratio of the male to female trees must be in a normal range of 9 to 12 percentage.Some liable aspects such as pollen tube penetration, embryo sac, endosperm, and embryo development up to 16 weeks after pollination were studied. Moreover, some lethal abnormality and abortions including ovule and ovary malformations were studied too. Collected samples were fixed in Carnoy's solution or FAA and/or glutaraldehyde and stored in 75% ethanol in the fridge up to processing time. Pollen tube was studied using aniline blue dye with UV light reflection. All samples for assessing the tissue or tissue problems were stained with toluodine blue O (TBO) and observed under a light Zise microscope. Data were analyzed by SAS analytical program and excel for graphs preparation. In conclusion, most of fruit abnormality and abortions were seen in the flowers located in lower part of the inflorescence and branchlets. A sort of gametophytic incompatibility was found in stigma tissue, which may be ended all to seed abnormality and abortion. These aspects mainly were megaspore mother cell abortion, stigma tissue failure to protect pollen and pollen tube, absence the embryo sac in the main place at nucellar tissue, embryo sac with unknown material. Moreover, degenerated embryo sacs, absence of embryo, disable embryos, broken growing embryos a while after anthesis, lack of endosperm and degeneration of the endosperm tissue in early and late growing periods. All mentioned factors found to be terminated to seedlessness in Pistacia atlantica subsp. Mutica (Baneh).

Qazvin province with an area of 1.58 km2 has various vegetation. It has different elevation from 300 m in Tarom to 4140 m in Alborz Mountain. In general this zone has about 61% mountainous and %39 those regions. A contribution to the flora, life form, geographical features property and use and harvesting calender is given. In this study 85 species callected and identificated. They belong to 33 families and 76 genera, 1 pteridophyta, 1 spermatophyta, 4 Monocotyledome and 27 dicotyledonae were identified. Lamiaceae with 21, Asteraceae with 10 and apiaceae with 6 species were the most families that have the highest number of species .Hemichrophyta with 33% and throphyta with 28% is the most frequent life form of gazvin province. Most of species are Iran –Torani distribution and collected from 1000 –2500 m.

High percent of medicines are used in developed countries have herbal origin. With regard to the development of saline lands and the shortage of agricultural lands, it comes into great importance to make use of salt tolerant plant. Cultivation of plants in hydroponic environment is a reliable and economical method in order to select the salt tolerant plant. An experiment was carried out in order to study the effect of different salinity levels on Cuminum cyminum and Valeriana officinalis in germination and seedling stages in a completely randomized design with four replications. The seed genotypes used were Mashhad, Serayan and Torbat-e-Jam. Salinity levels applied were zero (control), 50, 100, 150, 200 and 250 mM. The result showed that by increasing salinity level percentage of germination, root length, shoot length, root dry weight, and shoot dry weight, biomass, and shoot/root ratio decreased. This decrease was different among the studied plants and there was significant different between concentrations of salinity (p<0.01). C. cyminum had a high tolerance to salinity in their germination and seedling stages phase, but V. officinalis showed sensitive to increased salinity in this phase. In this experiment, Serayan genotype was more salt tolerant than other genotypes.

In this study mechanical properties of wheat straw flour / recycled polyethylene composite that had been made by using 15,30, 40% fine wheat straw flour(25-40mesh) and coarse wheat straw flour (12-25 mesh) as reinforcer with 2% Maleic Anhydride as coupling agents were investigated. Results showed that the increase wheat straw rate to 30% tensile and bending strength and to 40% tensile elastic moduls improved. But had no effect on impact strength. Also fine wheat straw flour particles had better effect on impact strength and tensile and bending elastic moduls. Wheat straw particle size had no significant effect on tensile and bending strength. Composite made by 30% wheat straw flour particle and 70% high density recycled polyethylene showed the best mechanical strength.

The aim of this research was investigation of relationship between litter quality and aerial parts on carbon, nitrogen, potassium and phosphorous of three range species: Agropyron intermedium, Bromus tomentellus and Stipa barbata. After identification of the species site in Taleghan the end of growing season (2004 autumn) aerial parts and litter in mentioned species were collected in this site. Sampelling was conducted in the key area of each site based on randomized systemic pattern. Number of determined plots was based on the characterstics of the studied sites. Data were analyzed spss under windows. The results showed in Ag.intermedium aerial parts the characterstics of C, N, P and C/N and in Br. tomentellus litter C, P and C/N rather than the other species. But in generally St.barbata litter and aerial parts quality was the best.

This investigation is done to study quantity of salicin and extractive materials in bark and leaf of white willow in the region of Agevlar, Daylaman and Khoshkebijar in Guilan province. After field sampling and bark drying, extraction was done according to TAPPI standard (T204om-88) by using acetone, ethanol and water solutions. Spectrophotometric method was used for measuring of salicin. Data was statistically analysed with SPSS software in levels of 1 and 5%. Results have shown that regions effect on extractive materials and salicin quantity in both bark and leaf, as these values reduce in Agevlar, Daylaman and Khoshkebijar respectively. The mean of extractive materials in bark and leaf are 13/03% and 29/74% respectively. The mean of salicin in bark and leaf of white willow are 7/36% and 8/64% respectively that there is not statistically a significant difference between them. This truth explained that the quantity of salicin in a tree bark and leaf are constant.