Year:2002 | Volume:15 | Issue:1 (54 IN NATURAL RESOURCES)|Papers Count:18

Ghavkhoni wetland is a protected area in about 140 km southeast of Esfahan. In this study a total of 63 species were identified. The following families have the highest number of species: Chenopodiaceae, Asteraceae and Brassicaceae. 33 species (52.4%) are endemics of Irano-Turanian region. Of these, 5 species are endemics of Iran: Callingonum bungei, Echinops robustus, Fortuynia garcinii, Paracaryum salsum and Sterigmostemum longistylum. Therophytes with 30 species (47.6%) are the most frequent life from in the wetland. The vegetation of Ghavkhoni wetland was studied, using the Braum-Blanquet school. 83 releves in different association individuals were recorded. Phytosociological data were analysed by FCA and HAC methods, using the computer program of Anaphyto. 14 associations were distinguished, that belong to 7 classes, 8 orders and 10 alliances. The following associations constitute the major part of the natural vegetation of the study area: Halocnemetum strobilacei, Seidlitzio romarini-Salsoletum turcomanicae, Astragaletum squarrosi, Seidlitzietum rosmarini and Artemisietum sieberi. The distribution and zonation of plant communities are mainly affected by ground level, water table and edaphic features including salinity, texture, organic matter and gypsum.

M. scutellata is one of the most important annual fodder botans of leguminous plants which because of its large grains capable of a high fodder potentially. It is of a special importance in nutrition of live stock. The alfalfa can be tilled periodically along with other cereals in the fallow lands in addition to producing a considerable amount of fodder it may prevent soil erosion and cause and increase in nitrogen and organic material of soil and improve its physico chemical properties. In different laboratory trial was made in station of agronomy research center of Khorramabad in split plot formats on the basis of RCBD with Breplication during two years of farming in 1994 and 1995. In this trial treatment row spacing of 30, 40, 50 cm in main plots and seed amount 5, 10-15 and 20 kg/ha in sub-plot. The test showed row spacing of 30cm over row proportion of 40 and 50 cm and seed amount of 20 and 15 kg/ha over 5 and 10 kg/ha. The greatest efficiency of grain and pod was preserved in row spacing of 30 cm and seed amount of 10 kg/ha with yield of 503 and 1336 kg/ha seed and pod.

Considering the influence of extraction method on the oil yield and essential oil composition, we examined three common methods of extraction (i.e. Kaiser, Clevenger and steam distillation) on the oil yield and essential oil composition of Eucalyptus camaldulensis Dehn. from Iran. The oils were producted at the yields of 0.22, 0.60 and 0.60% (based on fresh weights), respectively. The essential oils were then analysed by GC and separate limonene, b-phellandrene and 1, 8- cineile. Twenty two compounds were identitied which among them 1, 8- cineole (63.7, 48.8, 35.6%), p-cymene (15.2, 16.3, 21.3%), spathulenol (3.9, 3.7, 6.7%) and g-terpinene (5.1, 2.3, 2.5%) were the major constituents, respectively.

Twelve populations of Bromus tomentellus which were collected from different parts of the country were studied for various morphologic and karyotypic characteristics. The recorded data were analysed using appropriate model of analysis of variance.Obtaining confident result of differences between the populations for the morphologic and karyotypic characteristics, complementary analysis was performed on the data. The populations were classified for the different karyotypic characteristics and correlations between all combinations of the populations were estimated based on the karyotypic characteristics. Cluster analysis was used to classify the populations based on the morphological and karyotypic characteristics. The least and the most similar populations were identified based on the two sets of the data. A number of statistics were estimated for assymetry assessment of the karyotypes.Regarding the results of analysis of variance on the morphologic data, the populations were significantly different for all of the studied characters. The populations, their chromosomes and their interactions were significantly different for most of the karyotypic attributes. The populations were highly correlated based on the total length of the chromosomes but weak correlations were observed based on the long arm to short arm ratio for some combinations of the populations. Using cluster analysis results, the most distant populations based on the karyotypic characters which may cause infertility in their progenies due to incompatibility were recognized. The most distant populations based on their morphologic characters which may produce enough genetic variation in breeding projects were also identified.

Silybum marianum as a medical plant had an effect on protection of liver diseases and wide use in pharmaciatic industry in the world. Also, this plant has a lot of oil nutrient with high quality without harmful material. Oil is one of the byproducts of this plant that has a valuable pharmaciatic importance.However, this plant selfgrows in wide area in Khozestan province and it has adapted to this area, this plant growing on low level of rainfall and nutrition. Therefore, research to improve agrotechnique practices to use simoustiniouslly medical materials and oil of this plant is of important. In this respect, an experiment was conducted as a randomized complete block desion with 4 replications and 3 plant density (40000, 60000 and 80000 plant/ha) in Ramin Agricultural Research Field. Results obtained indicate that highest grain yield was obtained with 80000 plant/ha, (p<0.05). There was no differences between 40000 and 60000 plant/ha density (p<0.01).Grain oil concentration and grain thoushands weight were not influenced by plant density. However, the potential yield of this plant was 1976 kg/ha; with 30% oil content. These results are hopefull ones in this context.

Fire damaged approximately 720 ha of forest area in Golestan National Park during 1995. In this research, vegetation cover was investigated in 3 sub - sectors and plant community types were determined based on their importance value and index of dominance. Fire -damaged area included transient plant communities surrounded by Hyrcanian deciduous forest trees in the north and semi-savanna steppe vegetation of the Irano-Turanian biome in the south. Dominant vegetation type included members of Rosaceae, e.g. Pyrus boissieriana, Crataegus turcomanica, Prunus divaricata and Cotoneaster ovatus. Juniperus excelsa occupied higher mountainous areas. Gramineae were dominant grasses of the floor. Pattern of secondary succession of vegetation is discussed in early years after the fire incidence. Results of diversity indices of vegetation types showed a greater variation in fire-damaged zone than those of undamaged forest nearby. Grass species grew denser in fire-damaged zones while regeneration of woody species was tardy. Festuca drymeia community had recovered entirely.

Hypericum perforatum is an improtant medicinal plant. This plant has a great potential in phramaceutical industries. In order to produce callus, seeds of "Topas" cultivar were isolated and cultured on MS medium supplemented with 2, 4-0 (12.5 and 2.5 mg/l) and kinetin (0.1 and 1 mg/l). Callus proliferation was taken placed on the same medium for two months. Plantlets were regenerated MS medium containing BAP (2.5 and 5 mg/l) with NAA (2.5 and 5 mg/l). The results indicated high frequency of callus induction and the plantlets regeneration of this species. Increasing of BAP concentrations used higher number of plantlets. HPLC-OAO method was used to analysis secondary metabolites of callus and in vitro plantlets. The results showed that callus with red dot on its surface, lacking hypericin and pseudo hypericin, while in vitro regenerated plantlets had special nodes (black dots) containing hypericin and pseudohypericin. Production of other secondary metabolites (hyperforin, Ad-hyperforin, chlorogenic acid, Iso-chlorogenic acid and apijenin) on in vitro plantlets were higher than callus.

Samples of teak, keruing, balau and chengal were treated (impregnated) by coal tar oil (Creosote) using ruping method. The treated samples were compared with control samples of exotic wood, beech and oak (Iranian wood species) were also installed in sea water according to IRG/WP/4432. During 6, 9, 21, 28, 46 months, the samples were inspected according with recommendation of IRG/Wp/4432. During this installation period, all the control samples (no treated), expect chengal, were seriously attacked by marine borers. All the treated samples, expect balau, after 46 months installation in sea water, were undamaged. Treated samples of Balau after 21 months were attacked by marine Borers.

Total RNA isolated from A. elongatum treated with salt (150 mM NaCI), was reverse transcribed. The resulting cDNAs were amplified by two-step PCR, using one specific primer and oligo-dT. Four distinct bands of DNA were displayed in agarose gel electrophoresis, with approximately 501, 446, 398 and 356 base pairs. These were then excised, reamplified and the DNA used for hybridization, cloning and sequencing. Using southern blot analysis with the common oligonucleotide probe for non-specific lipid transfer proteins (nsLTPs), the band of the largest size was hybridized. After elution of the PCR bands, the cDNAs were cloned in PCR plasmid vector, and two of the clones (Les11 and Les12) with inserts were sequenced. The two clones were shown to be similar in nucleotide sequence and with a longer sequence for Les 11. The nucleotide sequence of Les11 showed 45% similarity to the oligonucleotide used as probe in the southern hybridization.It also showed a similarity of 41.5% to an nsLTP gene (blt 4.9). A new sequence was, however, obtained which included a possible expressed region.

Taxol, a diterpenoid secondary product of the yew species, has been recognized one of the best anticancer drugs to have emerged in the last 15 years. In this study we have measured the taxol content in various parts of the Taxus baccata L. grown on two natural populations (Noor and Gorgan) in Iran at different sampling dates and evaluated effect of environmental factors on taxol levels of the yew tree.Our results indicated that needles and roots contain the highest quantity of taxal in proportion to the other parts of tree (from 0.0285 to 0.055 and 0.023 to 0.047% of dry wt., respectively), the lower average yield were found in the bark and twigs, and the lowest average yield was associated with the branches (from 0.0013 to 0.005% of dry wt.) These results also indicated that the content of taxol in needles. Twigs and bark in both Gorgan and Noor natural populations in September were higher than June and December. Levels of taxol in needles, branches and roots in the native yew of Noor were higher than those of Gorgan. The levels were equal in twigs and reverse in bark. These results demonstrated that environmental factors are effective on taxol content in various parts of yew, and also suggest that foliage from yew trees growing in Iran may provide a renewable source for taxol production.

The determination of organochlorine pesticides in milk has been carried out through solid-phase extraction (SPE) and then separation and detection by a gas chromatographic method (GC- ECD). The procedure used for the extraction was an off-line method which uses a packed stainless-steel microcolumn (10mm x 3mm I.D.) Packed with 40 mg C18 packing. The microcolumn was used for 35-40 extractions. All the calibration curves were linear in the range 0.001-0.2 mg/m. Detection limits and percent recoveries for the above compounds varied between 8-30 ng/m and 30-60 percent, respectively. The developed method was applied to several milk samples including cow's, sheep's, pasturized and powdered milk.

In this paper, the influence of oblique waves attack on the stabilities of a reshaping breakwater roundhead have been investigated. This research has been carried out in the wave, basin of Soil Conservation & Watershed Management Research Center (SCWMRC), the Ministry of Jihad-e-Keshavarzi. Irregular waves were used in this research. The wave angles were 23 & 58 - degree respect to the breakwater centerline. The wave period was 12 sec and the number of wave was 1000 and 2000. The results of the experimental tests were drawn using the nondimensional parameters, showed the significant influence of the wave height on the stability of the breakwater roundhead. Also, it has been shown that the roundhead can be divided into regions having the same damage number. Therefore it is not required to cover all the regions with the same arm or size. Resulting in the reduction of construction expenses.

In this paper, the maximum wave run-up levels on berm breakwaters have been investigated. A berm breakwater is kind of reshaping breakwater, which its initial profile is changed to a (S) shaped one after impinging of waves. Therefore, the relations related to wave run-up levels on composite slopes can not be used for this type of structure. A series of experimental tests were performed in the wave flume of soil conservation and watershed management research center (SCWMRC), the Ministry of Jihad-e-Keshavarzy. The waves were generated using JONSWAP wave spectrum. To investigate the effects of wave and structural parameters on wave run-up levels, three parameters including significant wave height, structure freeboard and storm duration have been Totally 28 tests were carried out and the experimental results were plotted as graphs showing the maximum wave run-up levels versus the surf similarity parameter and deep water wave steepness. According to the experimental results, the maximum wave run-up levels can be determined as a function of a new parameter, called as non-dimensional reshaping parameter (S). This parameter is a function of significant wave height, structure free board, mean wave period, acceleration of gravity and nominal diameter of stones of armour layer.

Erosion damages are not limited only to soil loss and deposition of soil in water resources but nutrient loss is also one of the main damages caused by it. This study, which is conducted in steep slope tea lands with sandy textures, is aimed at finding the amount of nutrient loss (N.P.K) and its economic value. Using Cs.137 technique and zhang equation, average erosion on rate was found to be 3 ton/ha/yr. The amount of total N. and available P and K which were lost because of erosion are found to be 1.21 0.26 and 0.75 kg/ha/yr. The cost of the lost available nutrient amount to 1450 Ris/ha/yr. The results show that erosion plays an important role in the depletion of soil of nutrients and the economic value of the lost nutrients in very high. Nutrient loss is also a major factor in the pollution of water resources. Therefore, earring out soil conservation projects is a necessity.

In late February 1991, the burning of the Kuwaiti oil wells produced and emitted huge amounts of smokes in the region. Because of the importance of environmental impacts and for the completition of related previous studies, the emitted smoke was tracked for several days in February and March by a new image processing method. In this new method, a reference image was for considering the effects of the cloudy regions and another was used for the effects of specific atmospheric and land surface conditions.Therefore the smoke index for Iran and the whole region was determined. According to this index, and considering the burring of about 4 million barrels of crude oil per dag and the amount of spreaded soot by burning a unit of crude oil some analysis was done which resulted in an estimation of soot deposited in Iran. These estimations showed that from the beginning of the burning of oil wells to the end of March, approximately thirty-thousand tons of soot has been deposited in Iran by black rain.

In order to examine the factors affecting the normal growth and survival of plantlets of wild cherry (Prunus avium L.) after transferring from in vitro conditions into soil, an anatomical and physiological study was carried out on leaf, stomata in three conditions, in vitro and ex vitro, after 2 and 4 weeks. The anatomical observation, showed no significant differences between stomata of in vitro and ex vitro plantlets in shape, size and frequency. Stomata of in vitro showed.Malfunctioning in response to light, CO2 concentrations and water deficit comparing to those transferred and acclimatized in soil after 4 weeks. The concentrations of K+, Na+ and Ca2+ in leaves of in vitro plantlets indicated that these, ions could involve in this malfunctioning. The presence of high concentration of nitrogen and sodium in leaves of in vitro cultured of wild cherry could also inactivate ABA, resulting in lack of stomata responses to environmental stresses.

The north forests ecosystem of Iran having unique hyrcanian characteristics is one of the most important plant diversity due to altitudinal changes caused exclusive soil with evident differences comparing with other regions was formed in this ecosystem. This study along with recognizing important soil types due to plant cover was accomplished in Vaz experimental forest where has located in the north forests of Iran. So work units were segregated based on geomorphology, geology, plant cover and etc, and soil base - map was prepared, then a profile were dug in the place of each unig of this map on the ground. The changes of plant cover regarded as the most important indicator, 7 profiles among 27 ones were recognized, through phys-chemical analysis and after final conclusion. This study was performed at the framework of optimal natural resources management project in Vaz experimental forest, acqired results showed that beside plant cover changes in soil types, altitudinal and slope changes have an important role in pedogenesis and transformation of regions soils.