Year:2002 | Volume:15 | Issue:2 (55 IN NATURAL RESOURCES)|Papers Count:17

In this investigation, 608 ha of Palangdarreh region in south west of Qom province were floristically studied, based on physionomic-ecologic method. Totally, 407 species in 246 genera and 58 families were identified, and seven herbaceous and three shrub communities were determined. Dominant species were: Amygdales scoparia, Acer monspessulanum, Pteropyrum Olivier, Artemisia siberi, A. auucheri, Salvia multicaultis, Rheum ribes, Astragalus verrus and Tanacetum polycepyallum. The most and the least biodiversity was observed in Artemsia aucheri and Astragalus verrus community formations respectively. It is concluded that geographical orientation, gradient and altitude are the most important factors in vegetation composition of Palangdarreh region.

The genus Fritillaria (Liliaceae) comprises 125 species. In this investigation almost the composition of the nectar sugars of 30 species were analysed by PC and / or GLC. F. imperialis (subgenus Petilium) did not show detectable sucrose but the species in meleagris group (subgenus Fritillaria) Presented equal amount of fructose and glucose. The amount of fructose was much more than glucose in Crass folia, Caucasica and Kotschyana groups. Based on this study the classification of the genus Fritillaria to different subgenera and groups based of nectar sugars composition confirms the taxonomy of the genus based on morgholigical characters.

Quantitative and qualitative alternations of peroxidase and amylase after temperature treatments (-20, 4, 27, 500 c) were determined and compared with controls (sampling at 12' c). Quantitative and qualitative studies were done with spectrophotometric and gel electrophoresis methods, respectively. Investigation indicated that:1) Isoenzymatic pat terns of branch, leaf and seed were not same in sampling time.2) Qualitative alternations of isoenzyme in seeds are more than branches and leaves after temperature treatment.3) Enzyme activity of seed branches and leaves was not same.4) Peroxides and amylase activity of branch is very more than seed and leaf.5) Results indicated production of a specific enzyme band in branch, leaf and seed after frost stress. This investigation can be used as a model for monitoring.

Variation in anatomical and morphological characters of Ae.triuncialis populations of Iran was studied based on herbarium specimens, natural populations and field grown samples. Variation between populations of this species and the validity of different source of characters for delimitation of infra specific categories has been studied and discussed.

Artemisia annua from asteracea (compositae) family is an important aromatic plant of Iran. The aerial parts of this plant have aromatic compounds. In this research, plant materials were collected from five areas: Asalem (A1), Kapourchal (Anzali) (A2), Tamijan (Roudsar) (A3), Lahijan (M) and Ramsar (A5). After drying plants at room temperature far away sunlight, their essential oilswere extracted by hydro distillation method. Percentage of the oils was 0.41% (A1), 0.34% (A2), 0.35% (A3), 0.51% (M) and 0.27% (A5). The oils were analyzed by GC and GC/MS. They showed some differences and similarities. In sample A1, Artemisia ketone (19.36%); in sample A2, Camphor (21.52%); in sample A3, b-selinene (17.77%); in sample A4, Artemisia ketone (14.31 %) and in sample A5, b-selinene (13.42%) were the major components.

Fritillaria zagrica is an endemic species of Iran. It is distributed all along the Zagros mountain chain and is characterized morphologically by the distinctly dark purplish - brown flowers with a yellow apex. Its karyotype consists of two metacentric five subtelocentric and five telocentric chromosome pairs. In all metaphase plates only one pair of satellite – bearing chromosomes was found. C - banding pattern is characterized by the following major C - bands: centromeric bands occur in the short arms of chromosome pairs Nos. 2-3, 5-8, 10 and 12, and on the long arms of pairs Nos. 2, 4, 8-10 and 12; distinct intercalary bands exist in the short arms of pairs Nos. 1 and 6, and on the long arms of pairs Nos. 4, 6 and 11; telomeric bands occur on the short arm of pairs Nos. 1-3,7 and 9-11 and on the long arms of pairs Nos. 2-3. Bands at secondary constrictions are found on the short arm of pair No. 3. the short arms of chromosome pairs Nos. 3 (including satellites) and 1 and were entirely heterochromatic. Apart from these, there are some indistinct or dot - like bands in the complements, varying in number and general appearance from cell to cell. Heteromorphy for band width was observed in the pairs Nos. 2-3, 6, and 8. In addition to the normal complement (A chromosomes), 0-4 accessory B-chromosomes were observed in poplations GBK 20 and GBK 38. These chromosomes were of equal size and each had a terminal band, which suggests that they were probably telomeric and identical. Interphone nuclei exhibited a relatively heterogeneous matrix of chromo centers, varying in number and size. There were often a small number of big and distict chromocentres which at least in part may be related to B-chromosomes.

Essential oil of Mentha spicata L. was extracted by steam distillation method and its antimicrobial effects on Escherichia coli, Staphylococcus aureus, Pseudomonas, Klebsiella Pneumonia, Bacillus subtilis, Bacillus licheniformis, Streptococcus faecal is, Candida albicans and Saccharomyces cerevisiae were studied. Disc diffusion method was conducted to evaluate the zone of microbial growth inhibition at various concentrations of the essential oils. The antimicrobial effect was also studied against microbial suspensions to find out MIC (Minimal Inhibitory Concentration) and MBC (Minimal Bactericidal Concentration). The essential oil from Mentha spicata L. Was found to have remarkable antimicrobial property against all the microorganisms but P. aeroginosa. The oil exhibited its best antimicrobial activity within a maximum of 35 minutes. 15 components were identified by Gas Chromatography and Mass Spectrometry (GC and GC/MS) analysis of the oil, out of which Limonene (48%), Piperitone (20.27%), Caryophyllene (7.9%) and Menthol (4.7%) constitute major parts of the oil. Monoterpenes such as Limonene seem to have antimicrobial role.It seems necessary to explore antimicrobial properties of new harmless antimicrobial agents from natural sources as substitutes for prevailing chemical drugs.

Using floodwater in arid and semi arid areas of Iran is important especially in the recent years. Lateral intake is a method of floodwater diverting. In arid and semi-arid areas, floodwater has large amount of sediment that will be carried into the intakes and decreases the channel conveyance. There are several methods of sediment control in lateral intakes. Most of these methods are used in permanent river and irrigation canals. Also the amount of sediment inclusion into the intake and pattern of sedimentation has been analyzed. Experiments have been done for a 60-degree intake channel. Slope and width of main channel, width of lateral channel and bed material of main channel are constant in all experiments. For the selected bed material, there is only bed load sediment transport. Experiments have been done for three discharges and three depths for each discharge. The volume of sediment entered into the lateral channel and the volume of sediment transported in main channel have been measured. The pattern of sedimentation has been determined using topography information of entrance of lateral channel. The results showed that the volume of sediment transported into the lateral channel and the width of sedimentation area decrease with using sill.

In this paper, a theoretical model is presented to determine the coefficient of wave transmission through a series of upright perforated sheets. The sheets are installed normally to the direction of wave propagation. The model is based on the bulk dissipation of the incident wave energy by a single or a number of perforated sheet (s). The result of the model has been compared with the results of a series of experimental tests. The tests were performed in a wave flume using regular waves. The comparison had been shown that the wave transmission coefficients can accurately determined using the theoretical model.

In this study, the plant association as well the anthropogenic impacted area such as grazing and vegetation types was considered. The study carried out in 2500 hectare of Chelave forests of Amol city. These forests located at 800m to 1900m above sea level. here, traditional animal husbandry has experienced since some decade ago plant associations were identified, carried out by using Braun-Blanquet method. 65 sample plots (Releve) were selected, using the plant form and slope factors. Six associations and two subassociations, as well as one variant were recognized. Vegetation types and elements at the degrated forests and the cattle resting areas were also recognized. By comparing the natural forest associations with the impacted forest considered that a great change has occured within the targeted forests and some invasive woody species such as Crataegus ambigua, Mespilus germanica and Prunus avium has increased and the number of climax species decreased. Hence the main composition of the forest association was changed. By comparing of diversity indices of the sites in Chelave, it was found that, in spite of the exception, the wood species have had more diversity rather than original plant associations in disturbed forests. It could be occurred because of appearance of pioneer and invasive species and more uniformity in the distribution of individuals among above mentioned species.

Filling of locks in low lifts, generally accomplish by slots in gates and energy of flow dissipates by stilling basin and baffles. In this new system gate has been designed in the form of box and openings are made in two, upstream (U/S) and downstream (D/S) walls and flow control is done by these gates. This system includes a few orifices in U/S and some under sluice in D/S. Some laboratory tests have been done for determining discharge coefficient (Cd). Results show that (Cd) for this system is different from (Cd) for orifices and sluice gates. Generally the latter (Cd) is lower than the former. This is due to difference in orifice edges and hydraulic loss between two walls. An equation has been developed in this research for multi dabble orifices.

In this paper, a new analytical method for solving kinematic wave equations on converging planes, in which convergence of flow lines complicates the continuity equation, is presented. Veal (1966) derived the continuity and momentum equations in unsteady state for converging planes and numerical solutions for some special cases. Numerical solution of Veal’s equations has been reported by Woolhiser (1967, 1969) and Singh (1996) as well. This research is based on Agiralioglu method (1984) for determining the equilibrium(concentration) time on converging planes, by nondimensionalizing of Veals equations and determining the ratio of converging pal ne time to equilibrium to that of a rectangular plane. In the new method presented in this paper, location of wave front and the corresponding equilibrium discharge (Qe) at each time step are calculated. For translation of the calculated discharge at wave front location to the outlet, a reduction factor based on the varying degree of convergence in each time step is proposed.Multiplication of this factor by the Qe yields discharge at the outlet. This procedure must be iterated until the wave front reaches the outlet. Results of applying the new method and Woollier numerical technique to a representative problem are compared. The outcome indicates that the two methods present similar results, where the proposed in this paper is analytically-based and has no stability condition.

The poplar is one of the salicacea family or willows, which is a hydrophile and phototropism plant. It grows in the even texture soil with suitable ratio of clay, silt and sand particles. The runk length of this plant with special genetic and physiological properties and also it's phototropysm property has more growth with respect to it's stem, therefore it is a quich growing plant. The poplar plant has 5 subgenara such us: Louce, Agires, Tacamahaca, Turanga, Lecoides. In this research 55 colons of endemic and nonendomic species of 4 parts and 6 groups have been evaluated for 3 years in the selection nursery of the sarabtaveh research station in Yasuj. Different growing properties of colons under that climate condition and parameters needed for production of specific stem cutting, scion and suitable colons have been considered for choosing comparative popoltums. Characteristics which were considered are: measuring and determining of height and diameter of scions in the end of growth period, growing percentage for different planting time, scion existing percentage, the effect of ground cutting on plant growth, monotony of growth, recognition of diseases and plant pests, degree of colon's resistance and sensitiveness. The studied scions have been produced by simple stem cutting. Quantitative and qualitative in formations were collected in the end of growth season, after first growth period, scions have been cutted on the ground and in the later years by repeating nursery and ground cutting of one year scions and also repeating in later nursery, three kind of nursery (1/1, 1/2,2/3, years) have been produced. The result shows that: for the specific conditions of surveying place, two groups of poplar (Agires and louce) have the most growth with respect of the other four groups. Existing percentage of the Populus alba group is lower than others. The effect of unfavorable environmental conditions and resistance to diseases and pests of two groups: P. alba and Takamahaca is better than other groups, while other groups are sensitive and have reduction of growth. Ground cutting of one year scions to access sensitive scion caused different reaction of colons. The most growth was related to P. euramricana and P. deltoides groups and the lowest growth was for p. alba and p. ciliata. P. ciliata has the most sensitive to pests and diseases especially for xylophagous while P. alba group is more resistance to them. The endemic poplar has lower growth with respect to P. deltoides and P. euramricana groups.

This study is focused on evaluation of temperature effect during frozen storage on movement of trace elements in different tissues (exoskeleton. carapace and abdominal muscle) of two commercially important shrimp species (Penaeus merguiensis and Metapenaeus affinis).Moreover relationships between total length and sex of specimens with concentration of trace elements in selected tissues were assessed. Concentrations of Cd. Cr, Cu Fe. Mn, Ni and Zn in samples were determined by ICP-AES. Only in the case of Niand Zn sex related differences could be observed. With the exception of Cu. the tracemetals distributed significantly different between the tissues. The only significant differences between species were found in bioaccumulation of Mn. Size dependent relationship was observed only for Ni. Associatons between Mn and Fe were positively and highly significant in all the cases. The levels of all the metals in muscle of the shrimps from studied region were comparable to other world areas. Mean Cu and Zn levels in edible parts of M. affinis slored at - 10°c exceeded some existing guidelines, while the concentrations at – 300 were Same what lower hatlower than them.

The study, carried out in the ash (Fraxinus excelsior L.) stands, reveals that this species is distributed from lowlands to uplands (sub-Alpine) and from western to eastern parts of the Caspian forests and is well adapted to semi-humid to very humid climates with mild to very cold winters. Ash grows well on rich to relatively rich, humid with well to poor drainage, acidic to alkaline and silty loam to clay – loam soils and on different parent materials. So, it is found on various soil types such as gley, pseudogley, brown (forest br., washed br., acidic br., limestone b.), alluvial and culluvial with hydromull to mostly active mull humus types. In west of Gilan province, ash forms the association of Fraxino - Buxetum in plain and Fraxino - Aceretum in sub - alpine areas (to border of Rusco - Fagetum). It appears as Fraxino - Alnetum in wet plains of Mazandaran, and as Fraxino - Carpinetum in alluvial plains as well as in cool and humid valleys of Golestan Mountains. it is also found as: - Fraxino – Ouercetum castaneifoliae in upper limit of the Mediterranean vegetation region within valleys of the Alborz mountains. - Fraxino – Ouercetum atropatanae in highlands (upper limit of the Caspian Forests); -Fraxino - Tilietum at connection part of three climate types: Middle Asia, center plateau of Iran and eastern part of the Caspian Sea.Generally, ash dominant association is not estabished in forest types of Fagus orientalis, Quercus castaneifolia - Carpinus betulus and Parrotia persica, except on cool valleys with moist, rich and drained soils, creating mixed stands with other high demanding broadleaved species.