Year:2004 | Volume:16 | Issue:4 (61 IN NATURAL RESOURCES)|Papers Count:18

In this study the anti-microbial effects of A. persica’s essential oil were meticuslously investigated in the laboratory. In this investigation after collecting and drying the branches with leaves and flowers, essential oil extrcted by steam distillation, and then anti-microbial effect of this essential oil were investigated according to serial dilution on six microorganisms that is: E.coli, Pseudomonas aerogenosa, Entrobacter sp., Entrococcus, Staph saprophyticus and Candida albicans in test tube and then in solid medium of blood agar for two years with six repeatitions. The conclusions of each of six repeatitions showed that the minimal dilution of the essential oil which is able to control the bacterial growth is 1:128 (on pseudomonas) and maximal dilutions is 1:512 (on E.coli and Candida albicans).

In order to investigate the effect of different geographical origin of pollen grain in intraspecific hybridization and to achieve hybrids vigor, artificial hybridization has been carried out between different local genotype of Populus euphratica Oliv. from some wild growing stands of Iran. Because of long period required for embryo development on maternal plant, 45 days old ovary and ovule were used for in vitro culture. The isolated ovary and ovule were then transferred to the different kind of media (MS, Half MS and DKW). Significant difference (p=0.05) were observed between efficiency of pollinated ovaries (34.03%) and ovalses (47.47%) to produce plantlets. In spite of no significant difference between media used for embryo germination, the highest percentage of embryo germination was observed in MS medium (43.22%). Due to exist several numbers of ovales in each ovary (15-30), the highest number of plantlets was observed in ovary culture. No significant differences were observed between different origin of pollen grain (geographical regions) on percentage of embryo fertilization and germination. One hundred thirty seven plantlets were successfully acclimatized in a green house and transferred to the Field.

Abnormality of anther, the pollen number reduction and male sterility were stimulated under air pollution. Anther of Spartium junceum at different stages of development was collected from control (less polluted) and polluted areas (mainly SO, NO2, CO, HC, and Airborn Particulate Material, AAPM). Then structure of anther, walls and pollen were studied and compared. Groups of control pollen were exposed to Tehran polluted air at 10 and 20 days. Under polluted air, the anthers became abnormal and shrinked. The tapetum layer had a premature growth in pollen mother cell stage and a premature digestion at the tetrad stage. In some anther, pollen was fewer, smaller, shrinked and deformed compared to control. Exposure to gaseous pollutants caused collapse and thinning of the exine surface. Agglomeration of polluted particles on to pellen surface under humodity condition induced cellular material release. Protein content and SDS-PAGE patterns in polluted pollen did not show significant difference compared to control ones. Cytoplasmic material release increased in pollen collected of areas pollution.

Due to particular geographic situation, Iran has arid and semi arid climate in most areas. Rainfall condition and distribution in these areas is influenced by the geographic characteristics which causes of seasonal floods. These floods impose huge and irreparable damages. The aim of this research is decreasing of flood hazard. For this purpose by using time-area diagram, average slope, surface roughness coefficient, time of concentration, rain and runoff coefficient in a hydrologic model has calibrated and evaluated the behavior of watershed basin. Then isochron of basin was determined and spatial distribution condition of sub-basins has been surveyed. Since interaction between sub-basins spatial distribution and turtiality potential has an important role in arise of peak flood discharge in basin outlet. Therefore considering the implementation of flood control activities in the sub basins located in each isochron, their effect on peak flood hydrograph has been analyzed. The results of this research indicate that the number five isochron with 8870 km2 area has had the most effect in peak flood discharge in the basin outlet. In the contrary, the sub-basin located in isochron near outlet have had less important role in peak flood discharge. In general, from the outlet toward middle stream of basin along with increase in areas of isochron, the effects of sub-basins in peak flood discharge has showed an increasing. Thus concentrating on watershed management and flood control activities based on priorities and the areas identified achieving the research goals, will lead to considerable decrease in implementation expenses of the project.

In the present study four methods for shrub production measurement were compared namely: Adelaide technique, double sampling with usage of cover percentage for 20 and 25 percent direct sampling and clipping and weighing method. The result of clipping and weighing method was considered as index. Their accuracy and time consumption were compared. For this purpose four species including Artemisia sieberi, Eurotia ceratoides, Salsola rigida and Aellenia subaphylla were selected. The result showed that the best method for all shrubs (except Aellenia subaphylla) was double sampling with 20% direct sampling. The Adelaide technique can be an accurate method for Aellenia subaphylla, because this plant is big in height with sparse distribution of twigs and branches.Therefore using cover information in the double sampling method is recommended as the best method for shrub production measurement.

Sensitivity of geologic formations to erosion has important role in sediment yield of catchments. Field investigation indicates that a high percentage of sediment can originate from a small part of the catchment. This research has been carried out in two parts. 1- Investigations in Chandabe basin of Varamin as follows: River longitudinal profile, drainage patterns, k coefficient (in USLE model), of formations, area percentage or marl, area covered by different formations. 2- Investigation in flood spreading area including suspended sediment and permeability of the land. The sensitivity of formations to erosion was determined based on the above investigations as follows: Upper Red Formation is the most susceptible to erosion .Lower Red is highly susceptible to erosion. Hezar Dareh Formation, Tehran alluvium and most parts of Karaj Formation have medium susceptibility and Karaj Formation in highlands is resistant formation to erosion.

Using of seasonal floodwaters is very important in arid and semi-arid regions. In these areas, surface flow contains a lot of suspended particles that have an effective role in the reduction of infiltration; Therefore, the objective of this research is the investigating the effect of floodwater spreading on the Qoosheh soil project. In this regards, infiltration rate was measured in 30 points in the floodwater spreading area and in 5 points in the area without floodwater spreading as witness. The samples were collected in the center of triangles (sites for measuring infiltration) in the field to determine chemical and physical characteristics of soil layers, and the parameters such texture, pH, EC, Na+, Mg++ and Ca++. Based on the results obtained in this research, it is concluded that the sediments are caused variation in the soil texture. In the floodwater spreading area, sand percentage shows a decreasing of 2 times, and silt and clay show a decreasing of 2 times compare with the witness. Studying of chemical characteristics of soil also shows that pH and EC had little variation, but Mg++ and Ca++ had an increasing of 2 times and Na+ a decreasing of 2 times compare with the witness. Based on the data collected in the field, after 5 floods, the average of sediment thickness was about 9.0 cm in the back of embankments that caused a decreasing of 9.6 times of infiltration rate.

In order to determine the rate of litter decomposition of hornbeam (Carpinus betulus L.) at two forest stands, litters from Vaz and Asalem with different parent material were collected in autumn. Litters of in each region were put in four vases for 400 days at laboratory conditions. Sampling was carried out in 21 intervals and the nitrogen and carbon content were measured each interval. The result revealed that on the first day, contrary to C content, N content of litter was significantly different (p<0.05). The content of N was 1.13 % and 1.32 % in litter of Vaz and Asalem, respectively. The content of C was 43.38 % in Vaz and 41.12 % in Asalem. The rate of changes in C and N content and also the C/N ratio were statistically different in two regions. C/N of litter reduced from 38.39 to 18.21 and from 31.15 to 18.50 in Vaz and Asalem respectively. The decomposition rate of litter from Vaz region (calcareous parent material) was higher than those from Asalem region (acidic parent material).  

This research was done to study the applicability of kinematic wave approach in design of flood spreading systems and simulation of overland flow over spreading plots. To this, kinematic wave model was studied and was used to simulate the advance phase. It was assumed that flood-spreading plots have no transversal slope and water flows down stream in direction of longitudinal slope as sheet flow. Therefore, one dimensional shallow water flow equation could be applied. Priessman box scheme with an iterative method for time adjusting was selected to discretize the governing equations. To verify and evaluation of the model, three analytical and two numerical models as well as observations were used, respectively. Unfortunately, there was no recorded information about flow on flood spreading plots, to evaluate the model. So, observed data of 31 borders were used to different modeling procedures. Seven borders were omitted from analyses for the lack of accuracy, because of non-kinematic behavior of them. Five borders were used for sensitivity analysis and calibration. The remaining 19 borders were used to evaluate the model. Analyses showed that the model has no sensitivity on time step and time weighting factor of Priessman box scheme. Average relative error and prediction efficiency were, 7.8 and 99.45 percent, respectively.

Artemisia from Asteraceae (Compositae) family has 34 genus in Iran. With respect to its vast cover, density and distribution. It is one of the most important genus after Astragalus. Artemisia species have favorite characteristics from medicinal plants viewpoint.They have considerable amount of essential oils and aromatic compositions. In this research the essential oils isolated by hydrodistillation from the aerial parts of A. annua L, A. scoparia waldst. & kit, A. spicigera C. Koch., and A. absinthium L. that grow wild in the north of Iran were studied. The oils were analyzed by capillary GC and GC-MS. The most oil yield was obtained from A. absinthium (0.92%). The main constituent of the oils were as fallow:A. annua; artemisia ketone (14.3 %), A. scoparia; capillene (48.5%), A. spicigera; camphor (40.0%)، A. absinthium; α-phellandrene (25.5%).

Wood samples of teak (Tectona grandis) , keruing (Dipterocarpus alatus), yellow balau (Shorea laevis) and chengal (Balanocarpus heimii) were treated by Creosote, using ruping method. The dimension of samples were 200x75x20 mm and the retention were 188, 186, 331, 40 kg / m9 respectively. Both treated and untreated samples were installed in sea water (Mahshar in Persian gulf and Bandar Torkman and Noshahr in Caspian sea coasts) according to IRG/WP-4432(1985). In Mahshar coast, after 6, 10, 20, 23, 27 months and in Caspian sea coasts every 6 months and after 11 years the samples were inspected according to recommendation of IRG/WP-4432(1985). In Mahshar coasts (Persian Gulf), during this installation period, the control samples (no treated) of chengal and keruing were sound, samples of balau were severely degraded and Teak samples seriously attacked. All the treated samples after 27 months installation in sea water, were sound. In Caspian sea coasts, expect soft rot on the samples surfaces, both treated and untreated samples after 11 years installation were sound. It is concluded that there are no marine borers in Bandar Torkman and Noshar in south coasts of Caspian sea.

The oil constituents from the aerial parts of Varthemia persica DC. gathered from Tehran provience (Touchal) have been measured by GC and GC/MS . Thirty-two compounds were identified and the main constituents were β-Bourbonene(170/8%), β-Caryophyllene (10.8%), Germacrene D(10%) and Caryophyllene oxide (9.2%).

A vast area of country is covered by sand dunes and shifting sands in which threat the living of habitants in these regions. Biological control is a suitable method for sand dune fixation. So, it is essential to recognize the psammophyte plant species and their habitates. Ammodendron persicum is an species growing in a habitate in Zirkoh Qaen, east of Iran. In this investigation, botanical characteristics and habitate conditions of this plant was considered in terms of botany, topography, geomorphology, climatology, soil condition and plant vegetation. Ammodendron persicum is a prennial, shrub plant belongs to leguminosae family. It is cover about 134320 ha of sand dune area of this habitate. Three vegetation types including: Ammodendron, Ammodendron - Haloxylon and Haloxylon are separated in this habitate.The climatic condition of habitate is arid with average 150 mm of rainfall per year. Occuring high speed seasonal wind in this region causes wind erosion. Geologically, the habitate formed from sand dunes with different shapes and surrounding of habitate with Quarterner (Qt1 and Qt2), aluvial fan, and young and old terraces. The soil of this habitate has pH=7.6. EC= 1 mmos/cm2, non structural, containing lime with neglagable gypsum. The depth of sand is between less than a meter to about 50 meters above sand dunes. There are 22 villages around this habitate with 16604 population in which their economy depend on agriculture. In general this habitate is important in this region in terms of sand fixation and providing possibility of living for habitants. Furthermore, Ammodendron seems to be a good species for planting in other sand dunes areas.

Nowadays, an existing problem in wood industry is how wastes such as sawdust can be used again. One of the solutions going with this is composting Them. In this study it has been tried to consider and evaluate the quality of composting sawdust by adding some material such as brake fern. This study was done randomly in factorial plan, the factors were included sawdust of Populus euramericana and brake fern (in 3 levels), all repeated 4 times; Moreover; 4 cases were considered as control so they were totally 16. In this experiment, the pots were used because we wanted to omit the other environmental factors. The selected pots were sort of size 7 with 4 liter. After preparing 12 pots with sawdust, the provided amounts of brake fern randomly was allocated to the pots. Related to some amount of brake fern. We did so, just because the content of each pot is 4 liter therefore. For 25%, 50% and 75% of the pots content. i.e.1, 2, 3, liter respectively of brake fern were provided added by sawdust. After that, the pots were irrigated. Water added in samples up to some extent that they were not damped. The content of the pots were admixed with trowel that the air condition was done greatly. This work was repeated once a week. The pots were covered by plastic form while by creating the greenhouse condition, so we prevented the loss of energy, After 2 months the factors of N% the organic carbonate percentage. C/N, B% K% pH, EC & Bulk density were tested and measured on provided composts. The results were shown that about N%, C/N, K% & P%, the mixture sawdust of Populus euramericana with brake fern 75% were included the best results. Adding the brake fern caused no significant difference among the compost samples. All the results of EC showed that the plants have no problems to grow. As to bulk density the gained results that they stand in universal range.

Qazaan reserve covers an area of 5066 hectares, situated in the southern part of Kashan. This ecological area consists variety of habitats, including: plains, rocky slopes, debris and streams. Maximum and minimum elevation of study area varies from 3550 to 1600 m above level sea. Mean annual rain and temperature is 181.5 mm and 6.8˚C, respectively. A commented list of the plants of Qazaan reserve area is presented. 398 plant species are reported from the area. They are including two families of Pteridophyta, (Equisetaceae, Adiantaceae) and 396 Angiosperms (including 348 Dicotyledons, 48 Monocotyledons).Altogether, 61 families and 264 genera are known from the area. The families with high number of species are including, Compositae (54 species), Labiatae (41 species), Gramineae (38 species), Cruciferae (29 species), Umbelliferae and Caryophyllaceae (each with 21 species). 312 species (78.5%) are endemincs of Irano - Turanian region, of these 39 species are endemics of Iran, three species Astragalus eriostomus, Cousinia Kashanensis and Ferula kashanica are endemics of Qazaan reserve of Kashan. Therophytes with 147 species (36.9%), Hemicryptophytes with 141 species (35.4%), Chamephytes with 33 species (8.2%), Phanerophytes with 43 species (10.8%) and Geophytes with 34 species (8.5%) are the most important life forms of the reserve.