Showing 16 results for Morphology
G. Tahmasebi, R. Ebadi, N. Tajabadi, M. Akhondi, S. Faraj,
Volume 6, Issue 2 (7-2002)
Abstract
Small honeybee (Apis florea) is one of the common species in Iran. Apis florea lives in southern Iran and plays an important role in the polination of plants in this region. In a series of studies during the years 1997-1998, the genetic populations of the Iranian small honeybee and the effects of geographic and climatic conditions on the morphological variation and separation of Iranian small honeybee were investigated. For this purpose, 400 samples of worker bees from 40 colonies from 26 cities in 9 provinces were collected and twelve morphological characters were measured, using Ruttner method (1978). To determine geographical and climatological variables, average values collected by synoptic stations and other meteorological stations of Iran Meteorological Organization were used. The principal components analysis was used in the statistical analysis of the data obtained. The results show that there exist two distinct groups of small honeybee populations in Iran. Southwest of Iran hosts a class of bigger bees forming one distinct group while southeast of Iran hosts smaller bees forming the second group. Latitude has a positive correlation with size of body, wings and legs. Amount of precipitation has a nagative correlation with size of body, wings and legs. Temperature, wind speed. relative humidity, freezing days and other parameters did not show any correlations with size of body. The results from this research proved that the more northern areas with higher altitudes and more precipitation have bigger honeybees. This finding is in accordance with the Bergman law about other animals.
M. H. Farpour, M. K. Eghbal, H. Khademi,
Volume 7, Issue 3 (10-2003)
Abstract
Gypsiferous Aridisols are of great importance and extent in arid and semi-arid environments. There is a close relationship between soil genesis and landscape positions. This study aimed to determine the genesis and classification of gypsiferous soils and to investigate the relationship between micro-and macro-morphology of gypsum crystals and geomorphic positions in Rafsanjan area. The study area is located in Nough, 30 km north of Rafsanjan with a mean annual precipitation of 60 mm. Seven representative pedons were selected on different geomorphic positions. Physico-chemical, micromorphological, XRD, and SEM observations were performed on soil samples. Rock pediment geomorphic surfaces, that are in fact peripheries of old closed water bodies in central Iran, are the source of gypsum in the area. Large gypsum pendants and microforms of lenticular, vermiform, platy, and interlocked gypsum plates are found in rock pediment. The amount of gypsum and the size of pendants decrease moving down the slope. Lenticular and interlocked gypsum plates are found in a transition of pediment and playa. Puffy ground is observed on the saline surface of playa. Lenticular and vermiform gypsum crystals increase down the slope, but alabastrine gypsum is the most dominant form of gypsum in the playa surface. Large amounts of soft gypsum nodules are found on the rock pediment surface (western slope). In addition, spindle form of gypsum and palycrete bundles are observed in this position. Wind action played a significant role in the genesis and development of soil in rock pediment. A close relationship was found between morphology of gypsum crystals and geomorphic positions.
S. Ayoubi, M. Karimian Eghbal, A. Jalalian,
Volume 10, Issue 1 (4-2006)
Abstract
Paleosols include soils formed under climatic condition different from the present. Although such soils are widespread in central Iran region, adequate investigations of them are yet to be carried out. Micromorphology is one of the most important tools in plaeoclimatological studies. This investigation was carried out to study microscopic features of two paleosols from Isfahan province to reconstruct the paleoclimatic condition during the Quaternary. The results of this study indicate that strong clay coatings are presented in Sepahanshahr paleosol, indicating moisture regime in the past. This paleosol is polygenetic due to calcite and gypsum accumulation during drier periods compared to clay illuviation condition. Micromorphological features in Segzi paleosol indicate that this area has experienced a swampy environment during the younger Dryas. The overall results from this study indicate that climatic oscillation evidences during Quaternary have been preserved in paleosols from Isfahan region.
H. Yosef-Zadeh, M. Tabari, K. Spahbodi, Gh. Jalali,
Volume 12, Issue 44 (7-2008)
Abstract
In order to predict Caucasian maple (Acer velutinum Boiss. ) seedling growth based on nursery Orimel, Eighty six one year old seedlings located at 1550 meters above sea level in Sari, north of Iran were randomly selected. Collar diameter, height, leaf area, photosynthesis area and leaf area/leaf weight ratio were determined. Then multivariate regression models between leaf characteristics and growth characteristic were drawn. The results indicated that number of leaves and photosynthesis area can estimate the height growth of a seedling. Also, mentioned characteristics of leaf can estimate the biomass of stem as a well as growth characteristics. According to the correlation between growth characteristics and leaf characteristics, it would be concluded that the photosynthesis area of leaf can be suitable for early selection of seedling for reforestation. Also, this result shows the importance of increasing the establishment and growth of maple seedlings in plantation areas.
H Askarian, B Sharifnabi, M Olia, E Mahdikhani, A Akhavan,
Volume 13, Issue 47 (4-2009)
Abstract
Root knot nematodes (Meloidogyne spp.) cause yield loss in all countries, of which, M. javanica, is the most widespread species in Iran. In order to identify M. javanica, 100 infected root and soil samples of root knot nematode were collected from different regions of Kerman province. After purification of populations and identification of M. javanica based on morphological and morphometerical characters of females and second stage juveniles (J2), total DNA was extracted from eggs, J2 and female adults. Specific 670 and 1600 bp bands were amplified in all M. javanica populations using species-specific primer pairs including OPARjav / OPAFjav and Mjavf / Mjavr These specific bands could not be amplified in other species such as M. incognita and M. arenaria. It seems that, application of these species specific primers in comparison with morphological characters would be more applicable, leading to easier identification of M. javanica.
A Razavinasab, A Tajabadi, H Shirani, H Dashti,
Volume 13, Issue 47 (4-2009)
Abstract
To study the effect of nitrogen, salinity and organic matter on growth and root morphology of pistachio (Cv. Badami), a greenhouse experiment was conducted. Treatments consisted of four nitrogen (N) levels (0, 60, 120 and 180 mg kg-1 soil as urea), four salinity levels (0, 800, 1600 and 2400 mg NaCl kg-1 soil) and three organic matter (OM) levels (0, 2 and 4% soil as farmyard manure). Treatments were arranged in a factorial manner in a completely randomized design with three replications. As the salinity levels increased, leaf, stem and root dry weights and root density, were significantly reduced. Addition of N up to 120 mg kg-1 soil, had no significant effect on growth, but the highest N level (180 mg kg-1), due to nutrient imbalance, reduced abovementioned plant parameters. In low salinity levels, N application improved the growth of pistachio seedlings, but at the highest salinity level, N addition didn’t suppress the adverse effects of soil salinity. Due to useful physical and nutritional properties of soil organic matter, addition of OM significantly increased leaf, stem and root dry weights, stem height, shoot/root ratio and root density.
Sh Ghergherechi, F Khormali, Sh Ayoubi,
Volume 14, Issue 51 (4-2010)
Abstract
Gypsum is the most common sulfate mineral in soils of arid and semi-arid regions. Two hundred million hectares of the earth’s surface and about 28 million hectares of Iranian arid soils are covered by gypsiferous soils. The studied soils consist of alluvial plane and eolian plains in northern Iran. Soils were classified as Haplocambids, Aquisalids and Endoaquepts. In this study, genesis, formation and development of gypsum in soils were investigated. Study area includes different geomorphic surfaces from the upper watershed to alluvial plains. Gypsum crystals without considering their size, shape, arrangement are determined as pedogenic. In the weakly-developed horizons, in aridic moisture regimes, formation of euhedral pedogenic gypsum crystals and incomplete infilling of voids was dominant. In the well-developed soils, in xeric moisture regime, gypsum crystals are oriented and the perpendicular in arrangement of crystals along pores is dominants. Gypsum crystals occur in different shapes such as lenticular, tabular, and rosette-like and fan arrangement. Origin of gypsum in weakly-developed soils was weathered gypsiferous marls in upper Atrak basin. The source of gypsum in the soils with shallow ground water is high content of sulfate dissolved in soil solutions. In horizons affected by fluctuation of ground water contaning sulphur, euhedral tabular shape is dominant. In well-developed soils, based on Snowball morphology, gypsum is classified as stage II nodule. Results showed that there is no relationship between formation of the snowball morphology, b-fabric and kind of diagnostic horizons (A, B and C).
S. Shamsi Mahmoodabadi, F. Khormali,
Volume 15, Issue 55 (4-2011)
Abstract
In order to study the effects of different land uses on soil development, a loess hillslope was selected in Agh-Su area, eastern Golestan Province. Six profiles in four land uses including pasture, Quercuse natural forest, Cupressus artificial forest and a cultivated land, were dug and studied. Samples from different horizons were collected for physico-chemical and microscopic analyses. Important physical and chemical attributes such as bulk density (Bd), mean weight diameter (MWD), Organic carbon (SOC), cation exchange capacity (CEC), soil calcium carbonate (CCE) and available P were compared in land uses. Organic matter, CEC and MWD were significantly lower in the cultivated land use. Organic matter content in the forest and pasture area was considerably higher than that of cultivated land use. Soil profile development studies revealed that forest soils were highly developed. Quercus natural forest soils were classified as Calcic Argixerolls. Unlike cultivated soils which showed the minimum development and were classified as Typic Calcixerepts, formation of argillic horizon with dominant speckled b-fabric in the natural forest indicated the high landscape stability. Crystallitic b-fabric of horizons showed the absence of enough leaching of carbonate and the subsequent migration of clay particles. Intense erosion of the surface horizons of cultivated land use resulted in the outcropping of the subsurface carbonate rich horizon preventing soil development. The soils of pasture and Cuprecuse soils had mollic epipedon and were classified as Typic Calcixerolls with moderate development. Micromorphological properties of soils can help consider changes in pedogenic processes occurring under different land covers.
M. Ajami, F. Khormali,
Volume 15, Issue 57 (10-2011)
Abstract
Biological soil covers such as lichens have critical roles in soil stability and prevention of erosion. In order to study the effect of lichen biological covers on aggregate stability and soil conservation, loess hills covered with lichen and uncovered ones were selected in Northern Golestan Province. Five samples were taken from the depth 0 to 5 cm of both two areas for physico-chemical analyses. The undisturbed soil samples were taken for micromorphological studies, too. Analyses of soils revealed that soil organic carbon content increased markedly, compared to uncovered soils. Mean weight diameter also increased about three folds in soils covered with lichen. Fungal hyphae and polysaccharides excretions bind soil particles together and increase size of aggregates. Micromorphological study of thin sections showed that uncovered soils had a weak and massive structure, but soils covered with lichen had a crumb granular and also well -separated angular block and higher proportion of voids. Due to the effect of lichen on upward movement of calcium carbonate, crystallitic b-fabric appeared in the surface layer of covered soils and speckled b-fabric underneath. Excremental pedofeatures are the most common pedofeatures in the covered soils.
S. Sanjari, M. H. Farpoor, I. Esfandiarpour Borujeni, M. K. Eghbal,
Volume 15, Issue 58 (3-2012)
Abstract
Paleosols provide invaluable data on paleoclimatic conditions of the area. These soils widely exist in central Iran. Micromorphology and clay mineralogy are among valuable techniques which are useful for interpretation and identification of these soils. The present research was performed to compare the micromorphology and clay mineralogy of paleosols and modern soils of Jiroft area. After field studies, 4 pedons (located on different geomorphic surfaces including stable mantled pediment, stable and unstable transitional surfaces of pediment and alluvial plain, and stable surface of alluvial plain) were sampled for physicochemical, micromorphological, and clay mineralogical analyses. Clay coatings in argillic horizons of paleosols were found during micromorphology observations. On the other hand, clay coatings in present soils were only found in natric horizons, which were attributed to high amounts of Na in these soils. Moreover, smectite, palygorskite, illite, chlorite, and kaolinite clay minerals were recognized in paleosols, but chlorite was not detected in modern soils. The presence of palygorskite in the soils under study was related to the stability of geomorphic surface. Results of the present research showed that a more humid climate was present at the time of paleosols formation.
M. Liaghat, F. Khormali, S. A. Movahedynaeini, E. Dordipour,
Volume 16, Issue 61 (10-2012)
Abstract
Studies on the soils of western Golestan province show that regardless of increased rain and presence of clay minerals with high cation exchange capacity, potassium extractable with ammonium acetate is low. In order to find the reason for this low amount of available K, clay minerals and micromorphology of the soil porosity were studied. Twenty disturbed and undisturbed samples from each horizon were taken for physicochemical properties, mineralogy and micromorphological studies. Four selected profiles included Gypsic Aquisalids, Typic Endoaquepts, Typic Calcixerolls and Typic Hapludalfs. The results showed that in addition to the clay content and type of clay minerals in soils that can affect soil available K (Kava.), it seems soil porosity can also affect Kava. mainly through their effects on extension of roots, water and nutrients transmission. Favorable content of clay and dominance of smectites in Mollisols and also higher porosity and dominance of channel porosities caused the presence of higher Kava, in these soils. presence of HIS. poor soil drainage, reduction of Fe3+ in smectite crystal lattice in Inceptisols, and also less amount of porosities caused the presence of higher potassium fixation and reduction of Kava. in these soils.
M. Ajami, F. Khormali,
Volume 16, Issue 61 (10-2012)
Abstract
In order to study land degradation from the soil genesis and micromorphological perspective, ten soil profiles were dug and described on five slope positions in both forest and deforested cultivated land. The soil samples were taken from all horizons for physico-chemical analysis and micromorphological studies. Forest soils had a well developed argillic and calcic horizons and also mollic epipedon. These soils were classified as Alfisols and Mollisols. Carbonate leaching into the depth of soil profile and translocation of clays to lower layers and formation of developed soils are by no means related closely with the dense forest cover and its subsequent landscape stability and favorable leaching conditions. Dominant soil orders in this area were Inceptisols and Mollisols. In cultivated landuse, no argillic horizon was observed except in toeslope position. Absence of argillic horizon or its elimination following deforestation is one of the most important and obvious pedogenetic evidences of land degradation after land use change. Outcropping of high carbonatic layers (calcic horizon), disappearance of mollic and formation of ochric epipedon, presence of redoximorphic features attributed to runoff in lowland, decrease of solum thickness, and change of soil color were the other pedogenic indicators for land degradation in the study area. Microscopic observations showed that granular and crumb microstructures with high porosity were converted to massive and compact ones with low porosity in the deforested area. Disappearance of clay coatings besides absence of excremental pedofeatures were the other important micromorphological evidences of erosion and land degradation.
P. Asadi Alasvand, A. Heidari,
Volume 19, Issue 74 (1-2016)
Abstract
Technosols are modified soils affected by human activities. This study investigated genesis, classification and physicochemical properties of four pedons of Technosols developed on refused oil refinery materials and compared them with two unpolluted pedons. Mineralogical studies showed smectite as a dominant clay mineral with other clay minerals. These clay minerals adsorb oil compounds in their interlayer spaces and reduce their mobility and decomposition. Different micromorphological features resulting from oil compounds in soils, including depletion zones, types of coatings (quasi and hypocoating) and features due to horizontal and vertical movement of oil compound in soil showed dynamics of oil compounds and their effects on soil forming process. The refused petroleum compounds decrease pH and increase organic carbon, amorphous form of Iron in soils. Taking into account the presence of high amounts of gypsum and carbonate in polluted soil, the studied soils were classified as Typic Calcigypsids in Soil Taxonomy but in WRB system, due to the presence of impermeable geomembrane within 100 cm of soil surface, they were classified as Linic Technosols, showing the more precision of WRB system in their classification.
M. Zeraatpisheh, Sh. Ayoubi, H. Khademi, A. Jafari,
Volume 23, Issue 1 (6-2019)
Abstract
Landscapes are considered as a series of different land units with a size, shape and location arrangement that are permanently under the influence of natural events and human activities. Understanding the dynamics and heterogeneity of landscapes and environmental changes is of great importance. In order to quantitatively analyze and interpret the factors affecting the changes in the environment and terrain diversity, diversity indices were used to analyze the ecosystem. In this study, the relationships between soils evolution and geomorphic surfaces were investigated by applying pedodiversity indices in a part of a semi-arid region of Chaharmahal-Va-Bakhtiyari Province. In the studied area, three orders were recognized: Mollisols, Inceptisols, and Entisols. The results showed that soil evolution in the studied area was mostly influenced by topography, parent material and the underground water level; that is, in the higher lands, the lowest evolution was observed while in the plain ones, the soil of the higher evolution observed. In addition, the effect of geomorphic surfaces were obvious. Pedodiversity indices increased under the decrease of the hierarchy levels. In addition, the obtained equations revealed the nonlinear relationships in the area of geomorphic surfaces. The positive and nonlinear relationship between pedodiversity indices confirmed the nonlinear dynamic system in the studied soils.
A. Honarbakhsh, M. Fathi, M. Rostami,
Volume 23, Issue 4 (12-2019)
Abstract
In general, rivers are one of the best and most accessible water resources at the disposal of mankind. So, given the effect of the force of water and changes on the flow patterns and consequently, on river morphology changes, the analysis of the flow in the river is important and necessary to organize projects, flood control and water supply structures downstream. In this study, by using numerical models CCHE2D hydraulic conditions Dimeh River Bridge between Oregon Bridge Sudjan was investigated. CCHE Model is a mathematical model capable of simulating the flow patterns and sediment transport in rivers and canals laboratory network. The numerical model in 1998, based on the calculations by the National Centre for Water Science and Engineering, University of Mississippi (NCCHE), was developed and has been applied in many research projects related to water engineering. At the outset, the input data required model provides and numerical model was implemented. In the next step, the results of the model were calibrated and validated using field data measurements; eventually, they were extracted and their model results were compared; it was confirmed that CCHE model could still simulate the flow pattern.
A.r. Emadi, S. Fazeli, M. Hooshmand, S. Zamanzad-Ghavidel, R. Sobhani,
Volume 27, Issue 1 (5-2023)
Abstract
The agricultural sector as one of the most important sectors of water consumption has great importance for the sustainability of the country's water resources systems. The objective of this study was to estimate the river water abstraction (RWA) for agricultural consumption in the study area of Nobaran in the Namak Lake basin. The RWA was estimated using variables related to morphological, hydrological, and land use factors, as well as a combination of their variables collected through field sampling. Data mining methods such as adaptive-network-based fuzzy inference systems (ANFIS), group method of data handling (GMDH), radial basis function (RBF), and regression trees (Rtree) were also used to estimate the RWA variables. In the current study, the GMDH24 model with a combined scenario including the variables of river width, river depth, minimum flow, maximum flow, average flow, crop, and the garden cultivated area was adopted as the best model to estimate the RWA variable. The RMSE value for the combined scenario of the GMDH24 model was found to be 0.046 for estimating RWA in the Nobaran study area. The results showed that the performance of the GMDH24 model for estimating RWA for maximum values is very acceptable and promising. Therefore, modeling and identifying various variables that affect the optimal RWA rate for agricultural purposes fulfills the objectives of integrated water resources management (IWRM).
