Hassan Esmaeili; Javad Hadian; Mohammad Hossein Mirjalili; Hassan Rezadoost
Abstract
Satureja rechingeri, an endemic species from Iran, is distributed in narrow habitats in Ilam andKhuzestan provinces. This study was conducted in 2013 and some morphological characteristics, oilcontent, rosmarinic acid content and ecological features of different populations of S. rechingeriwere studied. ...
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Satureja rechingeri, an endemic species from Iran, is distributed in narrow habitats in Ilam andKhuzestan provinces. This study was conducted in 2013 and some morphological characteristics, oilcontent, rosmarinic acid content and ecological features of different populations of S. rechingeriwere studied. Identified habitats of S. rechingeri are located in sub-tropical areas of Ilam andkhuzistan provinces, within 32-33◦ longitude and 46-49◦ latitude and the plant mainly grows oncalcareous rocks in the northern and southern slopes. The highest coefficient of variation among thetraits of S. rechingeri was obtained for leaf surface area (43.01%) and the lowest (9.25%) wasobtained for the diameter of the calyx. The coefficient of variation for essential oil yield was33.71%. The lowest (2.1%) and the highest (3.51%) average essential oil yields were observed inKaver and Lives populations, respectively. Minimum (0.93%) and maximum (6.2%) essential oilyields were observed among the individuals of the Lives and Kaver populations, respectively.Highest (54.49%) coefficient of variation for rosmarinic acid content was observed in Bone Adabpopulation. Amount of rosmarinic acid of methanolic extract of under study populations showedhigh variability and varied from 0.54 to 7.29% among individuals, while the average rosmarinicacid in populations varied from 1.62 percent (Kaver population) to 4.14 percent (Zarrin Abadpopulation). Diversity of S. richingeri within populations was higher than among them showinglimited segregating of populations.
Nafise Panahi; amirhossein hamidian; Ali Tavili
Abstract
This study was conducted in Halgheh Darreh waste disposal site in Karaj in order to determine theconcentration of Ni and Pb in Halimocnemis pilifera and in region’s soil. Three 50*50 m plots inthe direction of the prevailing wind were selected. The First plot was close to the leachate pondsand ...
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This study was conducted in Halgheh Darreh waste disposal site in Karaj in order to determine theconcentration of Ni and Pb in Halimocnemis pilifera and in region’s soil. Three 50*50 m plots inthe direction of the prevailing wind were selected. The First plot was close to the leachate pondsand the next two plots were located at 500 and 1000 m from the first plot, respectively. Ten randomsamples from root and shoot of the plant and also from the soil were collected. The concentrationsof the metals were determined using a flame atomic absorption spectormetery (AA 240 (FS) VarianCompany, USA) after dry acid digestion. Two-way and one-way ANOVA were used to assess thedifferences of metal concentrations in roots and shoots of the plants, and in the soil of the plots,respectively. Duncan Test was applied to compare the average concentrations of metals in differentplots. The results revealed that the soil of the different plots do not have a significant difference inNi and Pb concentrations. No significant difference was observed between the metal concentrationsin roots and shoots of the plants. The plants in the second and third plots showed to have the highestconcentration of Pb (3.27 mg kg-1) and Ni (4.41 mg kg-1), respectively. Bioconcentration andtransmission factors for Ni and Pb (TF=1.21; 0.75 and BCF=1.11; 0.29, respectively) suggested thatH.pilifera is an appropriate plant to remove Pb and Ni from soil.
Mohammad Mahdi Hoseinzadeh; Reza Esmaili; Mohammad Hasan Jouri; Samaneh Pourkalhor
Abstract
Gully erosion is one of the most destructive types of hydraulic erosion and an important process insoil destruction that in some cases creates long, vast, deep canals. Study area was located in thenortheastern Alborz, Mazandaran province and Nowshar County (Firozkola subbasin a portion ofKojur watershed). ...
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Gully erosion is one of the most destructive types of hydraulic erosion and an important process insoil destruction that in some cases creates long, vast, deep canals. Study area was located in thenortheastern Alborz, Mazandaran province and Nowshar County (Firozkola subbasin a portion ofKojur watershed). This paper examines gully morphometery in relation with physical and chemicalcharacteristics of soil. The morphometery of gullies such as width, depth and slope were determinedin field. Physical and chemical properties of soil such as exchange cation (EC), organic andinorganic carbon, soil acidity and soil texture were determined in the laboratory. Data analyses wereperformed by Detrended correspondence analysis (DCA). The DCA analysis indicated that thewidth and slope are correlated with OC and clay negatively but they have positive correlation withpH. Hence, it's expected that following reduction of OC and clay and an increase in PH, gully widthboosts. Besides, if EC increases and CaCO3 decreases, depth and w/d ratio of gully will increase.
zohreh khorsandi; Mohammad Mahdavi; Ali Salajeghe; Saeid Eslamian
Abstract
Quantification of urban hydrologic response of catchments to rain fall is one of the most importantissues in urban hydrology. Despite its importance, there is scant information by means of whichrequired data can be obtained for quantifying hydrologic response. In this study, urban database wasdeveloped ...
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Quantification of urban hydrologic response of catchments to rain fall is one of the most importantissues in urban hydrology. Despite its importance, there is scant information by means of whichrequired data can be obtained for quantifying hydrologic response. In this study, urban database wasdeveloped for a part of Baharestan City in Isfahan Province and using the information, the urbanunit hydrograph was determined through URBS-UH model for two catchments of Baharestan. Peakof hydrograph of the first and second catchment was estimated 0.0727m3/s and 0.096, respectively.Flood hydrograph of some rain occurred previously in Baharestan was determined through the unithydrograph. Peak discharge of flood was also measured and the efficiency of the developed modelwas examined based on the peak information. Nash–Sutcliffe coefficient of the first and the secondcatchment were estimated 0.89 and 0.79, respectively. The developed model showed good to verygood performance in the pilot area.
bahram choubin; SHahram KHalighi Sigaroodi; Arash Malekian
Abstract
Predicting climate trends, especially forecasting rainfall, provides managers of different fields withsuitable tools so that considering these predictions; they can devise future-state policies. At thisstudy, after selecting the most effective climate indices applying PCA method, the effects of largescaleclimate ...
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Predicting climate trends, especially forecasting rainfall, provides managers of different fields withsuitable tools so that considering these predictions; they can devise future-state policies. At thisstudy, after selecting the most effective climate indices applying PCA method, the effects of largescaleclimate signals in seasonal rainfall of basin Maharlu - Bakhtegan were investigated bothsimultaneously and by delay through statistical methods (Pearson correlation and cross-correlationcoefficient) and by applying stepwise regression model, regression equation for forecasting rainfallwas offered. The results showed that in cross-correlation between the time series of SPI (dependentvariable) at time (t) and climate signals (independent variable) at time (t-k), only SOI indexconcurrently has a significant relationship with rainfall, whereas, most of indices turned significantwith standardized precipitation index with different lag times. In season to season study of thesignals with the standard precipitation index using Pearson's correlation coefficient it was found thatclimate signals of spring and summer are not significantly correlated with SPI. Representationcoefficients (R2) and standardized regression effect (Beta) in stepwise regression model showed thatsimultaneous and with season to season delays signals (for example: SPI index of autumn with fourprevious seasons indexes) at method Pearson correlation have higher relationship with seasonalstandardized precipitation index than the cross-correlation in time (t-k), (which signals of allseasons given is delay together with than SPI of all seasons) show.
Amin Zoratipour
Abstract
Abstract
Estimation of fine suspended load rivers is important in designing reserves, transition volume ofsediment, and estimating lake pollution. Thus, some methods are needed for determining damagescaused by sedimentations in environment and determining its effects on the watersheds. There aremany ...
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Abstract
Estimation of fine suspended load rivers is important in designing reserves, transition volume ofsediment, and estimating lake pollution. Thus, some methods are needed for determining damagescaused by sedimentations in environment and determining its effects on the watersheds. There aremany methods for estimating suspended load, one of these methods that solves the problems ofsediment discharge and can predict it is using Neuro fuzzy or ANFIS (Adaptive Network FuzzyInference System), and ANN (Artificial Neural Network) methods. These make a function betweensediment and simultaneous discharge by use of different algorithms. The goal of this research iscomparing the effectiveness of Neuro fuzzy, neural network artificial and statistical methods forestimating suspended load river in Glinak station of Taleghan Basin. It was found out thatsuspended load estimations of Nero fuzzy method with MAE 1006 ton/day, and correlationefficiency (R) 77%, RMSE 2621 ton/day and Nash-Sutcliff error (NS) 0.51 is better than NeuralNetwork Artificial and Statistical methods and Artificial Neural Network method rather thanStatistical Method are more proper. Also, contracting both neural networks artificial to fuzzy lawscan be illustrated better than other methods, variation of sediment Load River. One more merit ofthis method is that it is not sensitive to few errors in early statistical data and this fact enables betterestimation of neural network model in comparison with statistical model. Finally, Neuro fuzzymethod works better as the percent of train data to test data increases.
Mohammad Rostamtabar; Sadat Feiznia; ziaodin Shoaii
Abstract
More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, ...
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More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, mineralogical investigation has been performed qualitatively and quantitativelyby binoculars in laboratory. After that, sedimentation potential has been calculated by usingpractical formulas. Then, sedimentation potential of each sedimentary unit has been estimated fromaverage results of sedimentary sample and with this method, sedimentation potential of ShafaroodWatershed has been obtained from average results of five sub basins. An equation has beencalculated for each sub basin and by this, an equation for whole watershed was presented. In thisequation, the Y which refers to the amount of delivered sediments has been placed in one side androck unit coefficients on the other side. The coefficient of each rock unit has a rule in sedimentproduction. These coefficients are dimensionless and demonstrate rock unit sensitivity to erosion.The bigger this value, the more sensitive that rock unit is to erosion. In this way, the map ofsensitivity to erosion for each sub basin has been prepared by using (ARC GIS) software.According to average sedimentation potential of Shafarood Watershed, marl units (Pgf), silty sandyshale (Jsh) and sandy limestone (Kusl), have respectively the highest sensitivity and limestone units(P), andesite - basalt (Pev) and tuffy shale (V) have the least sensitivity to the erosion.
Sakine Saedi; Ali Akbar Mehrabi; Ali Tavili; Seideh Heydari
Abstract
Development impact assessment is key to achieving a comprehensive planning aligned with landsustainability. In human and natural systems studies, changes can be simultaneously examined intwo different systems. The purpose of this paper is to understand the effects of dam construction onland prices and ...
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Development impact assessment is key to achieving a comprehensive planning aligned with landsustainability. In human and natural systems studies, changes can be simultaneously examined intwo different systems. The purpose of this paper is to understand the effects of dam construction onland prices and land use change in nearby villages of Taleghan Dam. Descriptive - qualitativestatistics were used in this research and library and field methods were used for collecting therequired information. In order to specify the land value of the four villages of the area of the damfor four decaes, based on the prices of the year 1390, the land vlue formula was applied. Also, TMsatellite images of 1379 and 1386 were used for pinpointing land use changes. The results of thesestudies indicate that dam construction in 1380s and 1390s increased land price significantly andchanges in land price affected upon land use changes in nearby villages of dam and the price of landin the Zydasht village overlooking the dam increased dramatically.Based on the results of thisresearch, it can be stated that the dynamics of the land use of the area was affected by land pricethat for achieving sustainability in the watershed, an effective law must be enforced to prevent landdegradation and control land prices.
Nima Shakeri boroujeni; Hossein Bashari; Mostafa Tarkesh esfahani
Abstract
This study sought to develop a Decision Support System (DSS) for assisting range managers todetect range condition and make informed decisions about Feridan County rangelands. All plantspecies frequencies were measured in 31 range sites with various grazing histories using step pointmethod. Four hundred ...
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This study sought to develop a Decision Support System (DSS) for assisting range managers todetect range condition and make informed decisions about Feridan County rangelands. All plantspecies frequencies were measured in 31 range sites with various grazing histories using step pointmethod. Four hundred points along four perpendiculars 30 meters transects were measured in eachsite and grazing indicator species were identified using grazing gradient analysis. The rangeconditions of the sites were determined by evaluating the frequencies of indicator species alonggrazing gradient using Resource Environment Data Information System (REDIS). The bestmanagement practices and ecological interpretation for each range condition classes were theninserted into the REDIS model. The end users can import the indicator species frequencies of aselected site into the REDIS model and obtain the required information about range condition class,ecological information and management options. According to the results, the frequencies of sixrange species in the study area can appropriately determine range condition classes quantitatively.The model performance was then evaluated by comparing the range condition classes of 12independent sites by REDIS model and ‘Four Factors’ method. The REDIS model had an accuracyof 91 percent. The mangers can save the condition position of a selected site along a conditiongradient in REDIS model; hence they could simply monitor the range condition changes of thestudied site.
Ali Talebi; Shahrbanoo Abbasi Jondani
Abstract
WEPP model needs a great deal of input data. Identifying the model’s sensitive parameters andtheir prioritization increases the accuracy and efficiency of the model. On the other hand, WEPPmodel can simulate processes affecting on runoff, erosion and sediment throughout the year. Thus,model sensitivity ...
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WEPP model needs a great deal of input data. Identifying the model’s sensitive parameters andtheir prioritization increases the accuracy and efficiency of the model. On the other hand, WEPPmodel can simulate processes affecting on runoff, erosion and sediment throughout the year. Thus,model sensitivity must vary based on the storm occurrence time and parameters value in differentsections of the year. To prove this assumption, two spring and autumn storm events related to 2008were selected and sensitivity analysis of the WEPP model was done in three plots with differentconditions in Sanganeh watershed. For sensitivity analysis, the OAT method was used andsensitivity degree of parameters was calculated. Obtained results show that the rate of sand is themost sensitive parameter of WEPP model. This parameter was followed by other parameters likeclay percent, effective hydraulic conductivity, height and intensity of rainfall, day degree ofgrowing, growing season and percent of growing season when leaf area index decreases. Mostvariations are observed in prioritization of sensitive parameter in the plant/ management file. Inmost cases, sensitivity degree of these parameters in autumn event comparing to the spring eventhas significantly reduced in all plots. In general, obtained results show that the rate of sensitivity ofthe WEPP model to different parameters varies during the time. Hence, for using this complexmodel in regions with data limitation, the user must be aware to this issue that regarding storm time,which parameter is more sensitive in the pilot area and need to be carefully measured in the field.
Leila Fazel Dehkordi; Hossein Azarnivand; Mohammad Ali Zare Chahouki; Farhad Mahmoudi Kohan; Shahram Khalighi Sigaroudi
Abstract
To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based ...
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To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based on rainfall data; therefore, the rainfall data were used for measuring SPI andsatellite images were used for calculating NDVI. Also, the percentages of canopy cover in rangetypes were selected from the information of the National Evaluation of rangelands in differentclimatic zones. The correlation between SPI and NDVI and also canopy cover and NDVI wasexamined. The relationship between vegetation index (NDVI) and SPI was determined byregression. The results of SPI showed that in 2000 a severe drought and in 2006 a medium wetoccurred in rangelands of Ilam Province. NDVI value variations have as well confirmed it. Theresults showed that NDVI and life form (annual forb and annual grass) has the highest percentage ofcorrelation. Also examining of result showed that most correlation of SPI and NDVI was in 3 and 6-months intervals. Evaluation of regression models performance in range types described thatmodels in 3 and 6- months intervals was suitable for monitoring drought. The result of regressionconfirmed that NDVI was an appropriate index for monitoring and assessment of drought.
Mehdi Ghorbani; Vahid Jafarian; Mohammad Reza Yazdani; Mahsa Abdolshahnejad
Abstract
Achieving integrated natural resource management fundamentally needs effective and coordinatedrelationship, collaboration, and synergy among various actors who have common but differentresponsibilities. In this sense, the foundation of comprehensive and integrated management is notcompatible with centralization ...
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Achieving integrated natural resource management fundamentally needs effective and coordinatedrelationship, collaboration, and synergy among various actors who have common but differentresponsibilities. In this sense, the foundation of comprehensive and integrated management is notcompatible with centralization and top-down strategies. The aim of this paper is analysis of networkand organizational cohesion of natural resources stakeholders in Semnan province. In this study,relations of existing organizations within the network have been investigated based on interorganizationalinformation transfer and collaboration through social network analysis method andapplying macro-level and middle indexes of institutional network including; the network size,density, ties reciprocity, and centralization at macro-level and core-periphery index at middle level.Policy monitoring emphasized in present paper’s title refers to this question that how successfullynatural resource integrated management policies have been realized at least within the fourth andfifth development programs. Therefore, present study is an attempt to address this questionquantitatively and relying on the results of indexes of structural analysis of natural resourcestakeholders’ network in the pilot area. The results of this study indicate that institutional cohesionis 40 percent (poor) and sustainability of institutional network based on reciprocity is about 47percent (medium). Additionally the core-periphery index showed that the density of institutionalnetwork of Semnan province in core actors’ subgroup is 77 percent and in periphery actors’subgroup is 25 percent. Research findings identify existing capacities for applyin integrated naturalresources management and reveal the necessity of reducing network centralization andstrengthening the relationship among various stakeholders of this section.
Ataollah Kavian; Atta Safari; Aidin Parsakhoo
Abstract
In this study, the sediment yield of forest roads of Darabkola watershed was investigated andestimated using WARSEM and SEDMODEL. Rainfall simulator was applied to measure thesediment of abovementioned roads directly. In order to apply WARSEM and SEDMODEL models,field operations for measurement of different ...
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In this study, the sediment yield of forest roads of Darabkola watershed was investigated andestimated using WARSEM and SEDMODEL. Rainfall simulator was applied to measure thesediment of abovementioned roads directly. In order to apply WARSEM and SEDMODEL models,field operations for measurement of different parameters including road length and width, heightand coverage of road cut-slope, road longitudinal slope, shape and configuration of the road, roadsurface, and etc. were carried out in 63 different segments of the path of forest roads in the studyarea as 11979 meters long. Then sediment yield of roads was measured by rainfall simulator withnozzle of 3 meters high and plot of 2 square meters. Results of the WARSEM and SEDMODLmodels and rainfall simulation showed that sediment yield of forest roads are equal to 9.918, 5.109,and 4.141 kg/m2/year, respectively. Results also showed that there was no significant differencebetween sediment yield of rainfall simulation and SEDMODEL at significance level of %95. It wasalso revealed that SEDMODL is more suitable for estimating sediment yield of forest road withvalues of RD, MD, BIAS, RE and RMSE equal to 21.42, 4.54, 0.04, 17.59 and 0.71, respectively.
Sana Mohebbi; Ghasem Ali Dianati Tilaki; Mehdi Abedi
Abstract
Assessment of rangeland ecological characteristics have been proposed as an important factor inreviewing and monitoring the effects of various management measures and it demands differenttools for quantifying and offering a reasonable criterion for comparison of different managements.For this purpose, ...
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Assessment of rangeland ecological characteristics have been proposed as an important factor inreviewing and monitoring the effects of various management measures and it demands differenttools for quantifying and offering a reasonable criterion for comparison of different managements.For this purpose, the Landscape Function Analysis (LFA) method is capable of displaying thestructural and functional status of pastureland with considering the basic and simple indicators andit can be resorted to as a basis for selecting optimal and sustainable management. In this study, itwas found out that among different types of pasture management in Kojour Noshahr including;exclosure, grazing, plowing and planting management - in almost identical conditions regardingplant types, animal types, soil, geology, and climate the exclosure management was significantly(P<0/05) more favorable than other kinds of managements in terms of structural and functionalfeatures and it was followed by planting and grazing. Meanwhile, the plowed pastures weresignificantly unfavorable (P<0/05) both in terms of structural features and functional characteristics.Therefore; exclosure can be a perfect option to protect rangeland resources in this region.
Elham Meshkati; Hassan Ahmadi; Aliakbar Nazari Samani; M.H Davoodi
Abstract
Landslide occurs inevitably and naturally in many slopes due to sensitive formations, moisture, andother factors. Taleghan watershed is prone to landslide due to the presence of huge Miocene marlmasses. After construction of Taleghan reservoir dam, moisture and ecological condition of theregion changed. ...
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Landslide occurs inevitably and naturally in many slopes due to sensitive formations, moisture, andother factors. Taleghan watershed is prone to landslide due to the presence of huge Miocene marlmasses. After construction of Taleghan reservoir dam, moisture and ecological condition of theregion changed. In this paper, factors impacting upon landslide hazard (slope, aspect, hypsometry,geology, land use, distance to road, distance to lake) were studied and their role and importance onthis phenomenon were verified in a large (maximum distance of 1500 meter from lake) and a small(maximum distance of 450 meter from lake) spatial scale. Thus, GIS maps of the above mentionedparameters were provided using satellite and aerial images and field activities. All maps werecrossed with a resolution of 100m*100m. It was found out that the distance to the lake didn’tinfluence upon landslide in a large spatial scale but it falls effective as the distance to the lakereduces. In fact lake has a local effect and mostly influences at maximum 200 meter distance.
Amir Reza Keshtkar; Behnaz Asefjah; Yusef Erfanifard; Ali Afzali
Abstract
The development and implementation of practical natural resources and catchment managementpolicies require a comprehensive knowledge of the system processes (biological, physical, andsocio-economic), their complicated interactions, and how they react to different changes. Thecurrent research assessed ...
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The development and implementation of practical natural resources and catchment managementpolicies require a comprehensive knowledge of the system processes (biological, physical, andsocio-economic), their complicated interactions, and how they react to different changes. Thecurrent research assessed the ecological, physical, and socio-economic consequences ofbiologically-based management scenarios targeting runoff and soil erosion problems in theDarenari catchment. The Darenari catchment with an approximate area of 554 ha is located in Farsprovince, Iran. Three biological activities and 8 management scenarios were considered. Ecologicalconsequences were studied using the weighted land cover area index (WLCAI). Physical effectswere investigated applying the runoff curve number (SCS-CN) hydrologic model. Economic andsocial effects were assessed applying the cost/benefit analysis as well as examining the outcomes ofa social survey. Then, a fuzzy AHP approach was applied to weigh the criteria and ultimately, thebest management option was chosen using FTOPSIS model. The results showed that social criteriawith the highest weight and scenario No 8 was the best scenario and had first priority. The resultsidicated that the multi-criteria decision making techniques included capability of expressingdifferent aspects of the problem and are the perfect tool for watershed resources management.
AliB. Mirgalili; MohammadR. Fazelpoor; fariba zakizadeh
Abstract
Grazing animals affect rangeland vegetation structure and function both directly and indirectly.These effects can be assessed in exclosures. In this study, vegetation changes inside and outside ofexclosures of Tanglaybid rangelands, located in south-western part of Yazd province, have beeninvestigated. ...
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Grazing animals affect rangeland vegetation structure and function both directly and indirectly.These effects can be assessed in exclosures. In this study, vegetation changes inside and outside ofexclosures of Tanglaybid rangelands, located in south-western part of Yazd province, have beeninvestigated. Vegetation changes study was carried out in 3 key areas inside and also 3 key areasoutside of exclosure and lasted for 5 years (2000-2005). Every key area included 3 transects of 100meters long and 40 meters intervals. The transects were selected vertical to slope, including 10fixed plots (2×1 m2). Vegetation cover, density and frequency percentage of each plot species weremeasured annually. The random- systematic method was applied as a sampling method. Vegetationchanges inside and outside of exclosure were assessed, in a completely random plan, applyingDuncan's test (P < 0.05). The results showed that vegetation cover percentages increasedsignificantly (P < 0.05), inside the exclosure comparing to outside of it. Mean coverage of annualand perennial grasses and also bushes, inside the exclosure comparing to its outside increased 47,38 and 7%, respectively. Thus, in present research, exclosure has positive effects on vegetationcover changes of several species. Frequency percentage results showed that there was no significantdifference, inside against outside the exclosure in 2000, 2001, 2002, 2003, and 2004. Regardingdensity, there was significant difference only in 2001.The results can be considered in futuremanagement of the area's rangelands and similar regions throughout Iran
Mostafa Naderi; Asghar Mosleh arany; Gholamhosein Moradi; Abdosalam Piri; Mehrdad Kuhzadian; Hamid Azimzadeh
Abstract
This research aimed at studying the vegetation and investigating the effects of physiographic,edaphic and geological factors upon distribution of plant communities in Manesht district in Ilamprovince. Sampling was done based on plant types and land unit map. The number of samples wasdetermined by Krebs ...
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This research aimed at studying the vegetation and investigating the effects of physiographic,edaphic and geological factors upon distribution of plant communities in Manesht district in Ilamprovince. Sampling was done based on plant types and land unit map. The number of samples wasdetermined by Krebs method. In total, 125 square sampling plots of 400 2 m area were selected byrandom systematic method. To determine soil factors, two soil samples (0–30, 30-90 cm deep) werecollected from each land unit and physico-chemical parameters were measured. Using TWINSPAN,vegetation of study area was classified and then PCA and CCA were used to investigate therelationship between vegetation and environmental factors. Based on TWINSPAN, four vegetationgroups were recognized. According to TWINSPAN results, four ecological groups were identifiedthat first and second groups with 31 and 46 sample plots, respectively and by Quercus barantti,Crataegus pontica and Acer monspessulanum, as indicator species, are more calciphiles thananother groups. The first three axes of the PCA accounted for 62.83%, 23.45% and 13.72% of thetotal plant cover variability, respectively. Also based on Mont Carlo analysis, first and second axeswith 0.68 and 0.48 eigenvalue, accounted for 28% and 19% of the variability, respectively and thecorrelation coefficient of axes and species is 0.98. According to PCA and CCA, Formation, organicmatter and lime were the most important factors on establishing of ecological groups.
