Hossein Arzani; vahideh Abdollahi; Javad Motamedi; Majid Akhshi
Abstract
Nowadays, most attention is focused on physical and non-destructive methods, such as NIRS, to measure the chemical composition of rangeland species. Therefore, the purpose of this study is to provide calibration models for Infrared NIRS to estimate the forage quality of shrub species, so that in addition ...
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Nowadays, most attention is focused on physical and non-destructive methods, such as NIRS, to measure the chemical composition of rangeland species. Therefore, the purpose of this study is to provide calibration models for Infrared NIRS to estimate the forage quality of shrub species, so that in addition to saving time and cost, the quality of these plants could be estimated with proper accuracy. For this purpose, 654 samples of vegetative, flowering and seeding stages were irradiated by the DA7200 Perten Instrument to estimate the values of nitrogen (N), crude protein (CP), acid detergent fiber (ADF), dry matter digestiblility (DMD) and metabolizable energy (ME) via NIRS. Then, the data were transferred to the Unscrambler software for multivariate analysis. Before fitting the model, S.Golay and SNV methods were used for normalization of data distribution. Calibration and validation of model were performed using PLS1 method and Cross Validation method, respectively. Then, the predictability of models was evaluated by considering the calibration statistics. A total of 18 calibration programs were developed. Considering the calibration statistics, it could be said that the coefficient of determination was above 80% in all the factors studied. Also, at all growth stages, the correlation coefficient between the reference data and the data estimated by NIR was above 90%. Our results clearly showed that NIR calibrations obtained in this study could be used in current and future programs to assess the forage quality of shrub species used by livestock.
leila abdollahi; Mohammad Faraji; ali haghizadh; Somayeh Dehdari
Abstract
Abstract The effects of droughts on surface water and groundwater resources reduce the amount of water available to different sectors. Hydrological drought initially begins with decreasing rainfall and is usually associated with lower levels of lakes and reservoirs. To this end, in order to ma ke appropriate ...
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Abstract The effects of droughts on surface water and groundwater resources reduce the amount of water available to different sectors. Hydrological drought initially begins with decreasing rainfall and is usually associated with lower levels of lakes and reservoirs. To this end, in order to ma ke appropriate management decisions to prevent the harmful effects of drought, it is necessary to assess the characteristics of this phenomenon by assessing and monitoring the drought. In this research, the time series analysis and SDI shaking technique were used to evaluate the hydrological drought at the hydrometric station at the Marian River during the period from 1982 to 2015. The results of hydrological drought on the sunshine station showed that the highest frequency of droughts was related to mild droughts with 29.41% and severe drought with 11.74% and medium drought of 2.94%. Also, the results of self-correlation series analysis, which showed significant correlation for all months except Azar, before the analysis of its effect was removed by Hamed and Rao (modified by Mann-Kendal), and in December, the ordinary Mann-Kendall test used. In all months of the station, except for the month of Aban and Azar (non significant), during the period of 1982-2015, gradual changes are significant at 5% level, and the sudden changes of the time series are significant at 5% level and have a decreasing trend. Also, the results of the Paty's homogeneity test showed that the sudden changes in the time series were significant at all levels at the 5% level.
Massoud Borhani; rahele sadeghzade
Abstract
. This bulb root plant has essential oil with medicinal property. The great need for this product has led to a large harvest of its bulbs from the rangelands, which has significantly reduced its stands in recent years. The aim of this research is to determine the vegetative characteristics of Allium ...
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. This bulb root plant has essential oil with medicinal property. The great need for this product has led to a large harvest of its bulbs from the rangelands, which has significantly reduced its stands in recent years. The aim of this research is to determine the vegetative characteristics of Allium hirtifolium in Isfahan province. For this purpose, The presence of the plant was determined using field studies of 1395, and the ecological characteristics including topographic(elevation and slope), meteorology (rainfall, temperature, and climatic classes) and soil (Texture, salinity and acidity) were determined. Also using logistic regression model, the main factors influencing the presence of the species were identified. This species occur mainly in Astragalus community. The results showed that the highest presence of the species is in cold semi-arid climate with an average annual rainfall of 300 to 500 mm and an average annual temperature of 11 to 14 ° C. In terms of topographic factors, the species presence is mostly at altitudes between 2400 and 3000 meters above sea level and slopes of more than 20 percent. In terms of soil parameters, this plant is mainly in medium soil texture with a pH of 7 to 8 and an electrical conductivity of zero to 4 dsi Siemens / m. The logistic regression model showed that the two factors of elevation and precipitation had the most effect on presence of species.on species presence showed that topographic and rainfall factors had the most effect on species presence.
Sima Pourhashemi; mehdi boroghani; abolghasem Amirahmadi; MohamadAli Zanganeh Asadi; Mahdi Salhi
Abstract
Due to the drought and land use changes in recent years, dust storm phenomenon in Iran has increased. The purpose of this research is to identify and prioritize dust source areas using bivariate models (probability model of event weight and frequency ratio model) in R software environment and determine ...
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Due to the drought and land use changes in recent years, dust storm phenomenon in Iran has increased. The purpose of this research is to identify and prioritize dust source areas using bivariate models (probability model of event weight and frequency ratio model) in R software environment and determine the importance of each of the environmental factors affecting it in Khorasan Razavi province. To this porpuse, 65 dust extraction points were identified in the study area and a dust distribution map was prepared. Then maps of each of the factors influencing the occurrence of dust including soil maps, lithology, slope, vegetation index (NDVI), distance from the river, geomorphology and land use were prepared. Using the frequency and event weighting models, the weight of each effective factor and the relationship between each of the factors and the points of dust source were determined and, finally, priority maps of the dust source areas were prepared for the case study. Models were evaluated using the ROC curve. According to the results of both models, geomorphology units, land use and slope have the most effect on the occurrence of dust in the region, and both models have a frequency ratio and event weight with a sub-curve of 0.818 and 0.825, respectively. They accept.
ali dastranj; ahmad nohegar; Arash Malekian; Hamid gholami
Abstract
Abstract Vulnerability assessment and vulnerability mapping, is an important strategy to management of karst water resources. Due to the geomorphology of karst developed in karst aquifers and other natural conditions Azhvan-Bisotun area, Emissions are rapidly and widely. The aim of this study is mapping ...
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Abstract Vulnerability assessment and vulnerability mapping, is an important strategy to management of karst water resources. Due to the geomorphology of karst developed in karst aquifers and other natural conditions Azhvan-Bisotun area, Emissions are rapidly and widely. The aim of this study is mapping vulnerability Azhvan-Bisotun karst aquifer in Kermanshah province against surface contamination by using COP model. According to the aforementioned approach, the COP method considers three factors to assess the resource vulnerability: Overlying layers (O), Concentration of flow (C) and Precipitation regime (P). The results show that the vulnerability of the area between zero and 4.5, respectively, at the end of the five-class very high, high, medium, low and very low were classified. In general, the total area calculated parameters C, P and O have the most significant role in the vulnerability zone. The results demonstrate that COP is a useful method to assess the vulnerability of the test sites under consideration.
Morteza Khodagholi; Razieh Saboohi
Abstract
The genus of Astragalus accounts for 31.4 percent of area of Isfahan Province with Astragalus verus Olivier as a foremost species. This study aimed to investigate the contributing climatic variables to distribution of this species. Moreover, the trends of climatic variables and their influence on the ...
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The genus of Astragalus accounts for 31.4 percent of area of Isfahan Province with Astragalus verus Olivier as a foremost species. This study aimed to investigate the contributing climatic variables to distribution of this species. Moreover, the trends of climatic variables and their influence on the species mortality. In doing so, 56 climatic variables relating to January, March, July, and the entire year were utilized. The Principal Component Analysis was employed to trim down the number of variables and their trends were analyzed using the Mann-Kendall test. The correlation analysis was ultimately used to investigate the association between climatic changes and mortality of Astragalus verus. Results showed that cooling temperature contributed most in the distribution of the species. The trend of temperature also indicated that mean temperature followed an upwards trend in most months of the year. Except Ardestan, Isfahan, Eastern Isfahan, and Kaboutar-Abad, annual precipitation declined but not significantly at the level of 1 and 5 percent. The dried up stands observed in Naeen region was estimated to be around 25 percent where the largest decreasing precipitation and increasing temperature was recorded. This estimate was only around 8 percent in Khansar and Chadegan whose increasing temperature and wind speed as well as decreasing precipitation were compensated by having a good growing potential.
Farnoosh zareii; Hamed Joneidi; Parviz karami
Abstract
This research was carried out to evaluate the effect of rangeland conversion to afforestation with Cupressuss arizonica and Celtic caucasica on soil carbon emission. In order to determine the rate of carbon and carbon dioxide emission by tele-alkaline method with a stacking chamber, monthly was performed ...
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This research was carried out to evaluate the effect of rangeland conversion to afforestation with Cupressuss arizonica and Celtic caucasica on soil carbon emission. In order to determine the rate of carbon and carbon dioxide emission by tele-alkaline method with a stacking chamber, monthly was performed with 5 replicates per treatment and for one year. The analysis of carbon dioxide emission was done by one way ANOVA and Duncan's test. The results showed that the rate of carbon emission in Cupressus arizonica, Celtise caucasica and rangeland treatments was 110.49, 104.92 and 91.22 kg/ha/month, respectively and rate of carbon dioxide emission was 406.78, 384.71 and 48.433 kg/ha/month, respectively. The rate of carbon and carbon dioxide emission in 12 months in the area under consideration was also significant at 5% error level, have been with the highest carbon and carbon dioxide emissions in October and the lowest in August. In terms of seasonal distribution, the rate of carbon and carbon dioxide emission in rangeland and Cupressus arizonica treatments was not significant, but in the Celtise caucasica treatment was significant at 5% error level, with the highest carbon and carbon dioxide emission was in autumn, spring, winter and summer, respectively. In total, C.arizonica and C.caucasica reduced about 5/5% and 18% carbon and carbon dioxide emissions, respectively, than the adjacent rangeland did. Therefore, we can reduce the rate of carbon emission by appropriate management plans such as proper land use change.
Seyed Masoud Soleimanpour; Bahram Hedayati; Majid Soufi; Mohammad Javad Rousta; Samad Shadfar
Abstract
One of the important relations in the erosion of gullies is to study the threshold of erosion creation and expansion. In recent decade, creation of new knowledge in determination of relation between variables was led to develop prediction methods in different science and therefore, investigating the ...
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One of the important relations in the erosion of gullies is to study the threshold of erosion creation and expansion. In recent decade, creation of new knowledge in determination of relation between variables was led to develop prediction methods in different science and therefore, investigating the ability to use these methods in erosion and soil conservation is essential. Also, in order to control the erosion of the gully, the mechanism of gullies growth and its dimension expansion, especially increasing in gullies length, has to be carefully determine; for this purpose, the present study aimed to determine the threshold of the most effective factors on increasing the length of the gully, using the K-Means data mining algorithms and the CART decision tree in the Ghazian watershed in the north of Fars province. The results of this study, which include measuring various variables of gullies under field condition and in laboratory, and using data mining techniques, showed that increasing the length of gully in this area depended on the factors of the area above headcut, saturated extract electrical conductivity, forehead slope, canopy cover percentage, and sodium adsorption ratio. It is recommended control of erosion in the foreheads is highly important in reducing the increase in gullies length and sediment production. Also, improving the soils of this area with soil amendments and the restoration of compatible vegetation and the increase in soil organic matter should be considered as the priority of effective actions to control the increasing length of gullies.
Nafiseh Seyyed Nezhad Golkhatmi; Javad Bazrafshan; Arezo Nazi Ghameshlou; Parviz Irannejad
Abstract
North Atlantic Oscillation (NAO) is one of large-scale signal that affects the north hemisphere. Various studies have investigated the correlations between Iran’s precipitations and North Atlantic Oscillation from monthly to yearly scales. This study has considered weekly time scale. The daily ...
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North Atlantic Oscillation (NAO) is one of large-scale signal that affects the north hemisphere. Various studies have investigated the correlations between Iran’s precipitations and North Atlantic Oscillation from monthly to yearly scales. This study has considered weekly time scale. The daily precipitation variable was obtained from the ERA-Interim database (grid) and its compliance with ground reference points (synoptic) were investigated (1979-2016). The results showed that the amount of annual precipitation in regions with more humidity, especially in the Caspian region, is underestimated. Also, the correlation between grid and synoptic precipitation data in the western, northeastern and southeastern area of the country is the highest and in the strip parallel to the western-eastern line (the middle areas) is the lowest (weekly average). This correlation decreases from winter to autumn and spring, respectively. A review of the time series of the sever events of NAO during the year with the weekly scale showed that this signal had two peaks, which was used to select the time period of assessing the relationship between precipitation in Iran and NAO. The results showed that the correlation between grid precipitation and NAO is not completely direct and relative frequency of direct correlation is more than non-direct type and decreases from north to south.
Meisam Samadi; Abdolreza Bahremand; Ali Salajegheh; Majid Ownegh; Mohsen Hoseializade; Abolhasan Fathabadi
Abstract
In order to develop management plans for water and soil conservation, it is necessary to determine the sources of sediment production in watersheds. During the past three decades fingerprinting technique has been used extensively in determining the contribution of different sources of sediment. In this ...
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In order to develop management plans for water and soil conservation, it is necessary to determine the sources of sediment production in watersheds. During the past three decades fingerprinting technique has been used extensively in determining the contribution of different sources of sediment. In this study, was carried out sediments fingerprinting and determine the contribution of each source to sediment production of the Toulbane watershed in Golestan province. To this end, 44 source samples were collected from forest, pasture, agriculture and bank erosion. Also 8 sediment samples were collected using Philips time-integrated sediment sampler. Afterward, the concentration of 34 geochemical properties was examined in the laboratory using the ICP device. Next, the optimal composite tracers were determined to discriminate sediment sources by using statistical tests including mass conservation test and Kruskal-Wallis. The contribution of different sources to sediment production was determined using the multivariate mixing model. Finally, the uncertainty in the case of a low number of data, was examined using the Monte Carlo method. As a result, after statistical tests, 12 tracers were selected as the optimal composite fingerprints. The bank erosion was main source to sediment production with 52.18% and the forest had the lowest contribution to sediment production with 4.39%. The contribution of agriculture and pasture was 33.23% and 10.21%, respectively. According to the uncertainty analysis, bank erosion is the most significant source to sediment production. Also, the high difference between the upper and the lower boundaries in different sources indicates high uncertainty.
Sahar Samadi Khangah; Mehdi Moameri; Masoome Abbasi Khalaki
Abstract
The aim of this study was to investigate the ecological factors affecting the distribution of four Trifolium repense, T. pratense, T. micranthum and T. compestre species in Fandoghlou rangelands of Namin county in Ardabil province. Sampling was conducted in six sites with the presence and absence of ...
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The aim of this study was to investigate the ecological factors affecting the distribution of four Trifolium repense, T. pratense, T. micranthum and T. compestre species in Fandoghlou rangelands of Namin county in Ardabil province. Sampling was conducted in six sites with the presence and absence of species at random. Topographic, climatic, land cover and density of selected species were recorded. From each transect, soil samples were taken from the root activity depth the parameters of acidity, electrical conductivity, soil texture, lime, calcium, magnesium, sodium, phosphorus, potassium, organic matter, propagated clay and soil moisture content were measured. A significant difference was observed between the environmental factors on presence and absence of studied species by one-way ANOVA and comparison of the mean of the measured characteristics with Duncan test. To determine the importance of the variables in different sites and the species distribution, Linear Discriminant Analysis (LDA) was used. Results showed that there were significant different between the factors of electrical conductivity, slope, sodium, organic matter (p<0.01) and factors of elevation, rainfall, temperature, acidity, potassium, phosphorus, clay, silt, dispersible clay and bare soil (p<0.05) in sites of presence and absence of species. According to the results of the LDA, four functions were justified as 78.50, 15.60, 5.80, 0.10 %, respectively and totally 100% of the total variance of the data were justified. Four factors (temperature, electrical conductivity, potassium and clay) were identified as the most important factors in the distribution of the T. repense, T. pratense, T. micranthum, T. compestre species.
elham fakhimi; Hossein Naderi
Abstract
Floristic studies are fundamental for the applied sciences such as rangeland management and conservation. Rangelands of Sadrabad with an area of 40000 hectares is jocated in South West of Yazd province that it remarkable habitat for the floristic studies. In this study the floristic list of the region ...
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Floristic studies are fundamental for the applied sciences such as rangeland management and conservation. Rangelands of Sadrabad with an area of 40000 hectares is jocated in South West of Yazd province that it remarkable habitat for the floristic studies. In this study the floristic list of the region is presented and their life forms and endangered species are distingushed Plants were sampled following the common method in the regional taxonomic studies and their families, genera, and species were determined using indispensable references. The life form of plant species was determined using Raunkier’s method. The results showed that 235 plant species belonging to 39 families and 169 genera exist in this area. Hemicryptophytes, Therophytes, Chamaephytes, Geophytes and Phanerophytes included 36.45, 25.65, 23.47 , 7.82 and 6.55% of the total species, respectively. Furthermore, the endangered species of the region were identified on the basis of IUCN criteria and Red Data Book of Iran. Accordingly, 43endangered species were identified, of which 34 were in lower risk (LR) class, , 7 species were in vulnerable (VU) class, and 2 were put in data deficient (DD) class.
hamed farzi; reza tamartash; zeinab jafarian; Mohammad reza Tatian
Abstract
Restoring vegetation can change the structure and dynamics of vegetation, as well as the change in other parts of the ecosystem such as soil. The success of recovery efforts will be achieved when assessing the characteristics of ecosystems over time and comparing with the control areas. Therefore, the ...
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Restoring vegetation can change the structure and dynamics of vegetation, as well as the change in other parts of the ecosystem such as soil. The success of recovery efforts will be achieved when assessing the characteristics of ecosystems over time and comparing with the control areas. Therefore, the aim of this study was to investigate the effects of reducing plant cover and soil carbonation in rangelands of the southern slopes of central Alborz. Sampling from vegetation during the growing season of May and May was done in a systematic-random manner in 400 plots of 2 m2, along 40 transects of 100 meters. In each plot, crown cover percentage, species presence, functional characteristics of species including vegetative form, distribution type, pollination type and biological form were recorded. During each transect, two soil samples were harvested at different depths of 0-15 and 30-30 cm in different treatment and control areas. A total of 160 soil samples were collected from four different regenerative operations including clamping, seeding, grazing management, grazing and a natural rangeland as a control site. . showed that biological measures significantly changed the canopy cover percentage of three herbs. In the meanwhile, the Graminea strain in the regeneration zone and the legumes of Leguminosae and Cruciferae in the area had a significantly higher mean canopy percentage. The percentage of organic matter and the amount of organic carbon sequstration in the two depths of the soil and bottom of the soil in different biological operations at level have a significant difference.
sadat Feiznia; ahmad reza mokhtari; mohammad jaaferi; mohammad javad ghanei bafghi; ziba khodayian
Abstract
Mining and its various stages is one of the important factors in spreading pollution in natural environments. Contaminations may affect soil and water resources and actually enter the food chain due to absorption by plants. Among mineral elements, lead is more important because of its toxic effects. ...
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Mining and its various stages is one of the important factors in spreading pollution in natural environments. Contaminations may affect soil and water resources and actually enter the food chain due to absorption by plants. Among mineral elements, lead is more important because of its toxic effects. In order to investigate distribution of lead in downstream soils of Kushk Lead and Zinc Mine and identify anthropogenic and geogenic natures of pollution spread, a classified random systematic sampling was carried out. Sampling interval was 500 to1500 meters and soils were sampled in 0-5 and 5-30 centimeters depths. A control sample area with similar characteristics was considered in the vicinity of the region. The samples were analyzed by ICP-MASS method and the lead content of the samples was determined. Using Enrichment Factor and Geoaccumulation Index, the extension and severity of pollution are determined and related maps are prepared. Conclusions show that average amounts of lead in topsoil is about 4 times of subsoil and one kilometer far from mine, lead content of soil is more than 290 PPM that is more than permissible amounts. Moreover, the difference between lead content in topsoil and subsoil shows that the contamination in these areas is anthropogenic. Contamination reduces by going further from mine and the highest amount of emission of lead is around the main watercourse.
faeze Ghasem Nezhad; Fazeli Mehdi; Omolbanin Bazrafshan; Mohammad Parvinnia
Abstract
Drought monitoring by the Standardized Runoff Index (SRI) presents some uncertainties, mainly dependent on the choice of the probability distribution used to describe the cumulative precipitation and on the characteristics of the dataset. In this study, uncertainty analysis for estimation of the hydrologic ...
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Drought monitoring by the Standardized Runoff Index (SRI) presents some uncertainties, mainly dependent on the choice of the probability distribution used to describe the cumulative precipitation and on the characteristics of the dataset. In this study, uncertainty analysis for estimation of the hydrologic drought characteristics (intensity, duration and frequency) was performed. Four distribution functions, two time period (30 and 49 years), six time scales (3, 6, 9, 12, 24 and 48 months) and Latin hyper cube sampling (LHS) method ware used. For each event at per year and month, was generated 50000 random sampling.Then, lower and upper bands of certainty was calculated for confidence level of 95% . In addition to the drought characteristics (intensity, duration and frequency) were calculated for six time scales, four distribution functions and two length of time series . Investigation of the longest duration and highest intensities showed that an increase time scale led to decrease the frequencies of drought classes and as a result increase drought intensity and duration . Further, no significant difference in the assessment of intensity and duration was between various distribution functions, meanwhile significant difference was between normal compared to weibull and gamma for the estimation of drought frequency in short time scales (3 and 6 months). Results of this study emphasized that considering drought intensity and duration, the normal distribution function, 24-month time scale and 30-years’ time series had the largest uncertainty for hydrologic drought estimation.
S.Mahdi Taghipour; Shahram Khalighi Sigaroodi; Amir Alambaigi
Abstract
All rural and nomadic communities reside in natural watershed areas and, based on the specific climatic and geological conditions that each catchment area has, they are useful for living. Today, there is a danger to the livelihoods of non-residents as well as climate change caused by human activities, ...
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All rural and nomadic communities reside in natural watershed areas and, based on the specific climatic and geological conditions that each catchment area has, they are useful for living. Today, there is a danger to the livelihoods of non-residents as well as climate change caused by human activities, in other words, global warming due to the burning of fossil fuels. Accordingly, in this study, using the indices defined in the natural, social, physical, human and economic parameters, we examine the amount of five effective capital in the capacity of watershed adaptation to the climate change phenomenon in the three villages of Haji Abad, Gisur and Noodat Pashang In Gonabad city. In this study, due to climate homogeneity, 3 villages in the dry climate of Gonabad city have been selected. In this research, based on the questionnaire, the size of each of the five indicators and the organized interviews with the target groups in the three villages of the desert region were 3.13, 3.39, 3.14, 3.26, 7.2 was calculated. Also, using the Freeman test, it was found that there is a significant difference between different capital, which, respectively, social, human, physical, natural and economic, have the greatest impact on the capacity of aquaculture adaptation, so it is better to solve The watershed problem has used social and human capital to inflate other (physical, natural, and economic) capital
Zhila Ghorbani; Kiomars Sefidi; Farshad Keivan Behjou; Mehdi Moameri; Ali Ashraf Soltani Tolarod
Abstract
The most current way for measuring the soil fragmentation is determination of mean weight diameter (MWD). In this study, the adaptive neuro-fuzzy inference system (ANFIS) was used to predict of range soil fragmentation affected by different grazing intensities, distance from village and sampling depth. ...
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The most current way for measuring the soil fragmentation is determination of mean weight diameter (MWD). In this study, the adaptive neuro-fuzzy inference system (ANFIS) was used to predict of range soil fragmentation affected by different grazing intensities, distance from village and sampling depth. Present study conducted at 2015 in 3 adjacent rural areas (Alvars, Aldashin and Asbe marz) in Darvishchai watershed in Ardabil County. The studied parameters on the soil fragmentation including different grazing intensities in 3 levels (low, medium and high intensity), distance from village in 3 levels (200, 400 and 600 meters) and the soil sampling depths in 2 levels (0-15cm and 15-30cm). Obtained data were transferred to MATLAB software for the development of ANFIS models. For evaluating the models operation, mean squares error (MSE) and correlation (R2) were used. The result of best ANFIS model in prediction of soil fragmentation was compared with results of regression model. The results show that different grazing intensities, distance from village, sampling depth and their combinations had significant effect on the soil fragmentation. Increase of grazing intensity resulted in increment of soil fragmentation. With increment the distance from village from 200 to 400 meters, soil fragmentation decreased but with increment of distance, increased. Soil fragmentation in all conditions was higher at depth of 0-15 cm than depth of 15-30 cm. ANFIS model had more precision in prediction of soil fragmentation (R2=0.96) relative to regression model (R2=0.76).
Hamidreza Mirdavoodi; Adele Jalili; Ziba Jamzad; Ali Famaheini
Abstract
Classification of species in plant functional types (PFTs) according to Grime’s CSR theory has been found useful in understanding ecosystem functioning and processes and in quantifying variation along environmental gradients. The aim of this study was to assess variations in CSR strategies along ...
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Classification of species in plant functional types (PFTs) according to Grime’s CSR theory has been found useful in understanding ecosystem functioning and processes and in quantifying variation along environmental gradients. The aim of this study was to assess variations in CSR strategies along stress and grazing gradients in Meyghan playa of Arak. The strategy of plant species was determined according to the Grime’s CSR strategies, based on Pierce’s method. Random- Systematic design was applied to sampling. Two-way indicator species analysis (TWINSPAN) was applied to classification of the ecological plant groups, and partial canonical correspondence analysis (pCCA) was used to identify relationship between environment factors, disturbance and the plant groups studied, using the PC-ORD4.17 and CANOCO4.5 software, respectively. Among the factors that affect plant functional types and the structure of vegetation, soil salinity as a stress factor and grazing as a kind of disturbance were studied. Results showed that stress-tolerant peaked in conditions of high salinity. Competitors with a frequency of 14.3% were mostly present in conditions of low salinity and disturbance/light grazing. Ruderals with a frequency of 7.1% were mostly present in condition of overgrazing. The presences of competitor in protected areas with low soil salinity confirmed the theory of appearance of competitive strategy in low/stress-free areas and light/graze-free. Therefore, it may be possible to use Grimes’s PFTs for assessing environmental constraints and predicting whether a species with a specific strategy is likely to be positively or negatively affected by changes in environmental stress due, for instance, to climate change.
Reza Namjooyan; Jamshid Ghorbani; Ghodrat alah heydari; Ghorban Vahab Zade
Abstract
Activities related to the extraction of minerals are one of the factors causing a disturbance in rangelands. Vegetation succession in mining areas depends on the soil seed bank. For this purpose, the soil seed bank was studied in two important coal extraction sites in Mazandaran province to identify ...
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Activities related to the extraction of minerals are one of the factors causing a disturbance in rangelands. Vegetation succession in mining areas depends on the soil seed bank. For this purpose, the soil seed bank was studied in two important coal extraction sites in Mazandaran province to identify and compare seed amount between coal wastes and nearby rangeland as control. Soil and coal wastes samples were taken from 140 plots of 1 m2 in Kiasar coal mine and 115 plots in Karmozd coal mine before the growth season. Samples were kept in a glasshouse for eight months germinated seeds were counted. Results of this study showed that the germination of 28 species in Kiasar and 23 species in Karmozd. 10 and 6 species only presented in Karmozd and Kiasar coal waste, respectively. Annuals dominated the coal waste seed bank in Kiasar while perennials were common in Karmazd coal waste seed bank. In Kiasar, coal waste seed bank had less diversity and richness than that in seed bank of rangelands, but no significant differences were observed between seed bank of coal waste and seed bank of rangeland in Karmozd. Due to the harsh conditions of seed germination and seedling establishment and also low seed density in the seed bank, natural regeneration in coal wastes of these two sites will be a slow process and it needs amendment treatments and the introduction of target plants seeds.
Ali Yazdanpanahi; Khaled Ahmadaali; Salman Zare
Abstract
Biochar, as a soil reclamation material, has received attention by researchers during recent decades. In this study, a greenhouse experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement in order to investigate the effect of natural and municipal waste compost biochars ...
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Biochar, as a soil reclamation material, has received attention by researchers during recent decades. In this study, a greenhouse experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement in order to investigate the effect of natural and municipal waste compost biochars on the chemical properties of sandy soils from Kashan's sand dunes. The experimental treatments consisted of natural and municipal waste compost biochar each with four levels (0, 1, 3 and 5%) with the total of 16 culture media. Chemical analysis was performed for soil, biochar, and for 16 culture media resulting from these combinations in three replications. The results of analysis of variance and comparing means of measured characteristics (EC, pH, Ca, Mg, K, and OM) showed that these characteristics were significantly affected by the different levels of natural biochars. Soil pH decreased in some treatments and treatment No 5 had the most pH reduction. Both biochar treatments increased soil EC, pH, Ca, Mg, and OM by 5.5, 3.9, 2.4, 1.9, and 3.7 times, respectively. In general, treatment No 13 (soil + 5% natural biochar + 5% municipal waste compost biochar) had the highest influence on soil characteristics. As a practical application, the use of studied biochars as sources of Ca, Mg, K, and OM can be considered in soil reclamation projects and fertilizer management.
