Zahra Zamani; Reza Tamartash; Qodratolah Heidari; Zeynab Jafarian Jelodar
Volume 30, Issue 4 , February 2024, , Pages 489-504
Abstract
Abstract Background and objectives According to the studies, environmental factors can affect the secondary metabolites in plants, including the essential oil and its chemical composition. therefore, it is essential to understand the effect of these factors and which of the environmental factors ...
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Abstract Background and objectives According to the studies, environmental factors can affect the secondary metabolites in plants, including the essential oil and its chemical composition. therefore, it is essential to understand the effect of these factors and which of the environmental factors have a more effective role on the quantity and quality of secondary compounds extracted from plants. the purpose of this study is to investigate and compare the effect of physical and chemical properties of soil and climate factors including temperature and rainfall on the chemical composition of the essential oil of the medicinal species of Stachys lavandulifolia in the northern and southern aspects of Bagh tilak rangeland of Sari. MethodologyThe present research was conducted in Baghtilak rangeland, which is one of the summer pastures of Mazandaran province. in order to take samples, plant samples were taken according to the patchy distribution of the plant in the region, the aerial branches of the plant were randomly collected in three selected spots with three repetitions from the northern and southern aspects in late June.then the soil samples were also collected at the base of the plant from a depth of 0-30 cm. after the samples were transferred to the laboratory, the essential oils of the plants were extracted by clevenger and their composition was determined by GC and GC/MS. Soil samples were also measured and evaluated based on existing guidelines. also, the required meteorological information was obtained from the Kiyasar meteorological station. in order to analyze the quantitative and qualitative data of soil and essential oil, the normality of the data was first checked using the Kolmograph-Smirnov test. after confirming the normality of the data, using the independent T-student test, the comparison of plant chemical compositions and soil quality indicators in the two northern and southern spects was performed by SPSS version 22 software, and the relationship between the plant chemical composition data was analyzed. It was done with soil quality indicators and climatic data by PCA principal component analysis method in PC ord5 space. Results The results showed that the yield of essential oil in the southern aspect is significantly higher (P≤0.05) than the northern aspect. Also, among the compounds obtained from the essential oil, the compounds α-Pinene, α-Fenchene, p-cymene, Sabinene, Thymol, α-Thujene, Limonene, GermacreneD, bicyclogermacrene, cis-sabinene hydrate with the highest amount have a significant difference from they showed themselves in two aspects. the data obtained from principal component analysis into main components in relation to soil and climatic factors with essential oil compounds indicate that soil chemical factors including EC, OM, Mg, MWD, bulk density, sand and silt have a stronger relationship compared to other factors. also, in this analysis, soil factors such as apparent specific gravity, pH, Ca, sand, and the climatic factor of temperature have a positive and direct relationship with Sabinene, β-Pinene, Myrcene, α-phellandrene, p-cymene, Limonene, cis-sabinene hydrate compounds, thymol, Germacrene D, bicyclogermacrene and Phytol. also, soil factors such as EC, OM, bulk density, silt, Cao, P, Na, SAR and precipitation climatic factor have a negative and inverse relationship with Cyclofenchene, 1-8-Cineole, cis-ocimene, α- Terpineol, Terpinene-4-acetate, Bicyclo, Caryophyllene and Hexadecanoic acid were established. Conclusion The result of this research shows that the quantitative and qualitative performance of medicinal plants is affected by factors such as the type of species, climatic characteristics, soil characteristics and topographical conditions, and the effect of environmental factors on the components of secondary metabolites can be due to the different effects of these factors on The biosynthetic pathways of these compounds in the plant. also, the present study showed that the yield of essential oil obtained from the Stachys lavandulifolia plant in the southern aspect of Baghtilak rangeland is significantly higher than the northern aspect, so it is recommended to consider more for the exploitation of this aspect.
alireza Jamshidi; Navazollah Moradi; Marzieh Rezai
Volume 29, Issue 1 , February 2022, , Pages 112-132
Abstract
Changes in different solute compounds in edaphic factors affect the spatial distribution of plant species, especially hemicryptophytes.Soil salinity is one of the most common desertification factors in arid and semi-arid regions that contributes to the degradation of the soils of regions susceptible ...
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Changes in different solute compounds in edaphic factors affect the spatial distribution of plant species, especially hemicryptophytes.Soil salinity is one of the most common desertification factors in arid and semi-arid regions that contributes to the degradation of the soils of regions susceptible to desertification and eventually leads to a decreased soil ecological potential which is considered as one of the most significant factors that intensifies desertification. In order to explore the impact of principal components of soil on the diversity of plant types in the forest regions scattered along the coastal belt of the Persian Gulf and Oman Sea, current research was conducted on saline soils in Hasan Langi Village. Analysis of correlation coefficient between different traits of the plants in the respective vegetation (percentage of coverage, height and density and diversity) and the soil parameters of the habitats indicated that these vegetative parameters were mostly correlated with acidity, texture, and total calcium and magnesium. Principal component analysis (PCA) demonstrated that components 1 and 2 explained a total of 85% variance suggesting the largest impact of soil factors on differentiation of vegetation. In total, the factor of diversity was most correlated with calcium and magnesium in the second depth while other vegetative characteristics were directly correlated with the amount of sodium and potassium as well as electrical conduction in the first depth and the amount of calcium in the second depth.
Elham Nouri; Alireza Moshki; Mohammad Matinizadeh; Ali Asghar Zolfaghari; Saeede Rajaei
Volume 27, Issue 4 , December 2020, , Pages 631-671
Abstract
Due to their various roles in the plants’ life, the Arbuscular mycorrhizal fungi (AMF) has been studied from various aspects. In Iran, study on this type of fungi is still at its infancy. Also, the variety of plant species and populations in Iran necessitates a more in-depth analysis compared to ...
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Due to their various roles in the plants’ life, the Arbuscular mycorrhizal fungi (AMF) has been studied from various aspects. In Iran, study on this type of fungi is still at its infancy. Also, the variety of plant species and populations in Iran necessitates a more in-depth analysis compared to other countries in the world. The present study aimed at investigation of the effects of grazing intensity on the diversity and populations of these microorganisms that are symbiotic with the plants and also determining the factors affecting the soil. Three rangelands were considered with three different grazing pressures: no grazing pressure, managed grazing and heavy grazing. Following the sampling of the soil around the rhizosphere of the dominant plant species, the samples were transferred to the laboratory to be analyzed. The results of this study revealed the significant differences in the diversity of AMF species in different sites, and the highest frequency percentage was related to the Septoglomusconstrictum species identified in the heavy grazing region(42.2%).Also, grazing caused changes in the mycorrhizal symbiosis percentage and these factors had a direct correlation, and this could be an evidence of the reduced diversity of AMF, because despite of the existence of spores in the soil, each plant species can only correlate with specific species of AMF. It can be said that appropriate grazing cannot have a negative effect on the population and diversity of AMF, because species diversity indices in a managed grazing region are in a stable state; and, by the proper management of the grazing system and preventing the premature or excessive grazing, its harmful effects can be prevented.
Masoud Borhani; Zahra Jabeolansar
Volume 26, Issue 3 , September 2019, , Pages 741-753
Abstract
Correlation between vegetation and environmental variables is the most important issue related to the structure and function of rangeland ecosystems. Environmental factors such as climate, topography, and soil can alter the dynamics of plant communities. In this study, the effects ...
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Correlation between vegetation and environmental variables is the most important issue related to the structure and function of rangeland ecosystems. Environmental factors such as climate, topography, and soil can alter the dynamics of plant communities. In this study, the effects of environmental factors on vegetation of some rangeland sites in Semirom region of Isfahan province were evaluated. Sampling was carried out at 52 rangeland sites in a random-systematic way. At each location, 40 plots of one square meter were placed along four transects, and the percentage of vegetation cover in each plot was measured using ocular-estimate method. The grid layers of bioclimatic and topographic variables were prepared in ArcGIS 10.1 and values for each range site were extracted. Soil samples were collected from range sites and some physical and chemical properties of the samples were measured. Redundancy Analysis (RDA) was used to evaluate the relationships between environmental factors and the plant species cover. Cluster analysis was also used to group the studied range sites based on environmental factors. According to the results, annual mean temperature, isothermality, mean temperature of wettest quarter, soil texture, pH, organic matter, and elevation were identified as the most important ecological factors affecting plant species cover.
Farhad Fakhri; Mohammad jafari; Mohammadhosein Mahdian; Hosein Azarnivand
Volume 12, Issue 3 , August 2019, , Pages 235-248
Mohammad Khosroshahi; Majid Hasani; Shirin Mohammadkhan; Abbas Attarpour; Seyed Aziz Karami; Abolfazl Khalilpour; Ebrahim Farahani; Hamidreza Abbasi
Volume 10, Issue 4 , August 2019, , Pages 409-428
Hosein Arzani; Jalal Abdollahi; Mehdi farahpour; Mojganolsadat Azimi; ali Ashraf Jafari; Mahmoud Moalemi
Volume 12, Issue 3 , August 2019, , Pages 263-286
Jamshid Khatir Nameni
Volume 12, Issue 3 , August 2019, , Pages 311-334
Mansoureh Kargar; Zeynab Jafarian; Reza Tamartash; Seyed Jalil Alavi
Volume 25, Issue 3 , November 2018, , Pages 512-523
Abstract
Ecologists and environmental managers emphasize the use of predictive models to examine the species distribution patterns. The purpose of the present study was to investigate the efficiency of the generalized linear model (GLM) and generalized additive model (GAM) in determining the ...
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Ecologists and environmental managers emphasize the use of predictive models to examine the species distribution patterns. The purpose of the present study was to investigate the efficiency of the generalized linear model (GLM) and generalized additive model (GAM) in determining the relationship between vegetation and environmental factors in Khetteh Riz Rangelands. Environmental factors studied included soil characteristics, topographic factors and climatic factors. A classified-random sampling was performed and three dominant species, Bromus tomentollus, Ferula ovina, and Agropyron repens, were identified. The results showed that in the GLM model for Ferula ovina species, the variables of phosphorus content and slope were effective. For species Bromus tomentollus and Agropyron repens, the variables of annual moisture, rainfall, silt, and slope were effective. In the GAM model, the available moisture, silt and organic matter were the factors affecting the distribution of Ferula ovina. The silt, potassium, pH, and annual moisture content were the factors affecting the distribution of Agropyron repens. In addition, slope and silt were the variables affecting the distribution of Bromus tomentollus in the GAM model. The values of AUC, calculated for the GLM (0.63) and GAM (0.70), indicate the accuracy of the model to be acceptable.
Mahshid Souri; seyedeh Khadije mahdavi; sahra Tarverdizadeh saqzi
Volume 24, Issue 2 , July 2017, , Pages 360-369
Abstract
This research was aimed to investigate the effects of range improvement treatments on vegetation performance. The study was conducted in Silvana rangelands, West Azerbaijan province. In this study, four improvement treatments including contour furrow, pitting, gabion and mortar stone dams were selected. ...
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This research was aimed to investigate the effects of range improvement treatments on vegetation performance. The study was conducted in Silvana rangelands, West Azerbaijan province. In this study, four improvement treatments including contour furrow, pitting, gabion and mortar stone dams were selected. A control site (with no improvement treatment) was also selected. Vegetation sampling was done in a random-systematic manner in key areas of each site. Vegetation parameters including production, canopy cover percentage, litter and density were measured Data were analyzed by one-way ANOVA. Then, the mean values of parameters were compared with each other using the Duncan test. Statistical analysis was done in SPSS software. The results of one-way variance analysis indicated that the study mechanical improvement treatments had significant difference in terms of performance of plant parameters. According to the results, among the study treatments, contour furrow and mortar stone dam had the most positive impact on increasing and improving the performance of plant parameters, compared to other treatments in Silvana region.
Mohammad Khosroshahi; Morteza Abtahi; Mohammadtaghi Kashki; Sakine Lotfinasab; Fateme dargahian; Zohre Ebrahimi
Volume 24, Issue 2 , July 2017, , Pages 404-417
Abstract
So far, different statistics have been presented for the area of deserts in the world and Iran by individuals and organizations. The reason for this difference is mainly due to the disagreement among experts in providing a comprehensive definition of desert and factors affecting its formation. In this ...
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So far, different statistics have been presented for the area of deserts in the world and Iran by individuals and organizations. The reason for this difference is mainly due to the disagreement among experts in providing a comprehensive definition of desert and factors affecting its formation. In this paper, the factors of natural environment, such as climate, vegetation, geomorphology, soil, geology and hydrology, whose effects are directly or indirectly involved in the emergence and general appearance of the desert, were investigated. Therefore, to identify and define the desert ranges in terms of the study factors, a number of indicators were defined, based on which desert zones were identified for each factor individually. Then, digital maps were produced by overlaying the layers. Results showed that the largest area of desert regions in Iran with a surface of 693690 and 567711 square kilometers is influenced by climatic and vegetation factors, respectively, and the least area of desert regions with a surface area of 208041 and 272,258 km is affected by the geological and geomorphologic factors, respectively. From the aspect of soil science, the area of desert regions in Iran covers a surface of 514930 km2. The total area of deserts was calculated to be 9007293 square kilometers, which accounts for 55 percent of the total area of Iran.
zahra jafari; Hamid Niknahad gharmakher; maryam ghasemi; isa jafari
Volume 24, Issue 1 , May 2017, , Pages 80-88
Abstract
Todays, conversion of forests and rangelands to croplands has made concern about soil and environmental degradation and global climate change. Knowledge of the effects of land use change on soil properties is necessary and can be a solution for identifying sustainable managements in any region in order ...
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Todays, conversion of forests and rangelands to croplands has made concern about soil and environmental degradation and global climate change. Knowledge of the effects of land use change on soil properties is necessary and can be a solution for identifying sustainable managements in any region in order to prevent soil degradation and reach to sustainable production and environmental purposes, either. In the past decades, large part of Avard rangelands has been converted to croplands. In recent years, gardening on these low efficiency agricultural lands has been suggested. The aim of this study was to investigate the effects of gardening on some soil physical and chemical properties compared with rangeland and cropland in Avard region. At first, the study area was identified by field survey and then, three composite soil samples were obtained from depth of 0-30 cm of key area of each treatment (rangeland, walnut Garden, walnut – apple garden, cereal farm, and frijol farm). Some soil physical and chemical properties including texture, aggregate stability, bulk density and porosity, organic carbon, pH, and electrical conductivity were measured in laboratory and soil erodibility index was calculated by using the modified clay ratio relation. Data analysis was performed by SPSS.16.0 software and one way analysis of variance. In order to compare the means of studied parameters, tukey test at a significance level of 5% was applied. The results demonstrated that soil aggregate stability and electrical conductivity were significantly improved (P<0.5) as a result of gardening on the low efficiency agricultural lands, but other soil properties such as soil organic carbon were not significantly improved (P>0.5). According to the results, it can be concluded that the best land use in the study area is natural rangelands. Establishment of orchards in the low efficiency arable lands of the study area is recommended, either.
savan shahrokhi; Mahshid Souri; javad moetamedi; Alireza Eftekhari
Volume 24, Issue 1 , May 2017, , Pages 98-109
Abstract
Global warming has devastating effects on the lives of organisms, causing damage to natural ecosystems, floods, droughts and climatic and ecological imbalance. Resonance effects of greenhouse gases in the atmosphere as a result of carbon dioxide concentration causes warming, melting polar ice caps, ...
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Global warming has devastating effects on the lives of organisms, causing damage to natural ecosystems, floods, droughts and climatic and ecological imbalance. Resonance effects of greenhouse gases in the atmosphere as a result of carbon dioxide concentration causes warming, melting polar ice caps, massive flooding, and deforestation. Biological carbon sequestration is soil and plants' ability to absorb carbon dioxide from the atmosphere and store it in plant and soil. Therefore, it is a method that helps to reduce atmospheric carbon and to mitigate the consequences of climate changes. In this project, the effects of restoration rangeland practices (contour furrow) on carbon sequestration were investigated in Khalifan region of Mahabad. For this purpose, in each study site (contour furrow and control), four 100-m transects were established. Along each transect, five plots spaced 20 m apart were set up systematically. At the beginning and end of each transect, a profile was excavated at two depths (0-15 and 15-30 cm). Soil and plant samples were transferred to the laboratory. Plant biomass was measured in all plots by cutting and weighing method. Carbon sequestration rate was determined for each of the samples. The data were analyzed by ANOVA and T-test. The results indicated that the highest rate of carbon sequestration in the study sites belonged to the litter. The results demonstrated that the rate of carbon sequestration in both biomass and soil in contour furrow site was higher in comparison with control site. This can be due to the positive effect of contour furrow practice on the amount of participation storage in soil, run off and erosion control and increasing the vegetation.
Seyedeh khadijeh Mahdavi; Mahshid Souri; Ahmad Choupanian
Volume 22, Issue 2 , August 2015, , Pages 289-297
Abstract
Increased concentration of carbon dioxide in the atmosphere is the main cause of climate change, having harmful effects for human beings. Reducing the amount of this gas by inhibiting industrial development and the use of artificial methods is not suitable due to the lack of economic justification. Therefore, ...
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Increased concentration of carbon dioxide in the atmosphere is the main cause of climate change, having harmful effects for human beings. Reducing the amount of this gas by inhibiting industrial development and the use of artificial methods is not suitable due to the lack of economic justification. Therefore, taking advantage of carbon storage potential in plant tissue and soil has attracted much attention in recent decades. According to the different climatic zones in the country, studying the carbon sequestration in each of these areas should be taken into consideration. Therefore, the potential of soil carbon sequestration in the mountain rangelands of Kermanshah Province was studied in three height classes and four aspects. Then, soil samples were taken from two depths of 0-30 cm and 30-60 cm in the habitats of Astragalus gossypinus and Astragalu sparrowianus. Soil organic carbon, bulk density, electrical conductivity, pH, moisture content and soil texture were measured in both soil depths. Stepwise regression results showed that soil parameters including texture, bulk density and pH, were the most important factors, affecting soil organic carbon. Based on the results of data analysis in a completely randomized factorial design, significant differences were observed for soil carbon sequestration among height classes and aspects at 1% level of significance. According to the results of mean comparisons based on SNK test, the highest amount of carbon sequestration was observed in the third height class and north aspect. Our results clearly showed that Astragalus parrowianus had a higher potential in soil carbon sequestration as compared to Astragalus gossypinus.
sedighe zarekia; hosein arzani; mohamad jafari; noloufar zare
Volume 22, Issue 4 , March 2015, , Pages 745-756
Abstract
This research was aimed to investigate the effects of different grazing systems and intensities on soil and vegetation properties. Initially, the canopy cover percentage, density, and species height were measured using systematic random sampling. To investigate the changes in soil parameters in ...
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This research was aimed to investigate the effects of different grazing systems and intensities on soil and vegetation properties. Initially, the canopy cover percentage, density, and species height were measured using systematic random sampling. To investigate the changes in soil parameters in each area, 15 soil profiles were taken from 0 to 20 cm depth by systematic random sampling method. Data were analyzed in a completely randomized design. Also, continuous and heavy grazing during the year led to the removal of key species and changes in species composition. According to the results, continuous and heavy grazing resulted in increased soil potassium and phosphorous content. However, pH in none of the study sites was not statistically significant. Nitrogen and organic matter content did not differ significantly among the study sites. In addition, no grazing at exclosure increased the soil permeability. Although exclosure and rotation grazing at a moderate grazing intensity could desirably increase the vegetation cover, it had no significant effect on soil chemical properties. Generally, since arid regions are fragile ecosystems, the management of these areasshould include economic and biological considerations.
Azin Jafarian; Mohammad Jafari; علی طویلی
Volume 21, Issue 1 , June 2014, , Pages 51-61
Abstract
Ecological effects of Haloxylon plantation on natural vegetation and soil properties were investigated in this study. For this purpose, three regions with 1 to 5-year-old, 5 to 10-year-old and over 20-year-old Haloxylon (Haloxylon persicum) and a control area for each region were determined. Vegetation ...
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Ecological effects of Haloxylon plantation on natural vegetation and soil properties were investigated in this study. For this purpose, three regions with 1 to 5-year-old, 5 to 10-year-old and over 20-year-old Haloxylon (Haloxylon persicum) and a control area for each region were determined. Vegetation sampling was conducted along a 300-meter transect to record crown cover percentage, density, production, litter, gravel ،bare soil ،species diversity and dominant species. In addition, soil sampling was performed at depths of 0-30 and 30-90 cm to measure soil properties including EC, pH, percentage of organic carbon, soluble calcium, magnesium and sodium, and silt, clay and gravel percentage. The study was performed through random-systematic sampling. Data were analyzed using independent t-test in SPSS software. Results indicated that Haloxylon plantation led to increase in percentage of crown cover, litter, and standing crop production. It also caused improvement in species composition, condition and trend as compared to the control area. Plantation of Haloxylon with different ages affected and increased soil electrical conductivity.
Asghar Kohandel; Hossein Arzani; Morteza Hosseini Tavassol
Volume 17, Issue 4 , November 2011, , Pages 518-526
Abstract
Different grazing intensities change the chemical and physical properties of soil and plant composition of rangelands. Accordingly, effect of livestock grazing intensities on soil and vegetation characteristics were investigated in the southeastern of Hashtgerd using Principal Component Analysis. Principal ...
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Different grazing intensities change the chemical and physical properties of soil and plant composition of rangelands. Accordingly, effect of livestock grazing intensities on soil and vegetation characteristics were investigated in the southeastern of Hashtgerd using Principal Component Analysis. Principal Component Analysis is a statistical method for defining new variables based on a linear combination of original variables. Three 5-ha areas were selected in the study area under treatments of no, moderate, high and continuous grazing intensities. Afterward, vegetation and important physical and chemical soil characteristics including moisture, specific gravity, soil porosity, infiltration, mechanical resistance, nitrogen, phosphor, potassium, pH, EC, soil texture and organic matter were measured in three grazing treatments for two years (2004 and 2005). According to the results, increase of grazing intensity increased forbs while grasses and shrubs decreased. Among soil properities, soil porosity and Mechanical resistance decreasid and pH, EC and K had the highest relationship with grazing intensity.
Masoud Borhani; Hossein Arzani; Zahra Jaberolansar; Mojgan Azimi; Mahdi Farahpor
Volume 17, Issue 1 , September 2010, , Pages 1-20
Abstract
Range condition is known as an important indicator for assessment in range management. Many techniques have been exploited for determining this indicator, from which four-factor method has been used in this study. Some communities at stepic regions of Isfahan province were selected. In each selected ...
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Range condition is known as an important indicator for assessment in range management. Many techniques have been exploited for determining this indicator, from which four-factor method has been used in this study. Some communities at stepic regions of Isfahan province were selected. In each selected community, an area was chosen as key area, and a total of eight sites were selected in the key areas. Soil erosion, canopy cover, plant composition, and plant vigor were monitored for each site. The results revealed a significant difference between the sites in terms of the above mentioned parameters, as well as their rainfall (p<0.01). Moreover, there was a significant correlation between annual precipitation and range condition score. The correlation showed different patterns within years in each site, where the difference between years was significant in terms of plant vigor and canopy cover, but non-significant in terms of soil erosion and plant composition. There was also a positive correlation between the trend of individual parameters and the overall condition score. Cluster analysis grouped Aluyjeh, Northern Shahreza, and Charmshahr sites in one branch, Mooteh, Shoorabad, and Golpayegan in another, and finally Komeshcheh and Southern Shahreza in a third branch. The lowest rank for canopy cover, canopy production and soil erosion belonged to Komeshcheh and Southern Shahreza sites. Aluyjeh, Northern Shahreza, and Charmshahr sites were in better condition than the previous group, yet in poor conditions, and the rest of the sites showed the best conditions among study sites. Generally speaking, Isfahan's stepic rangelands are ranked as poor to very poor, while their condition showed a constant trend.
Nejatali Salar
Volume 16, Issue 2 , December 2009, , Pages 224-233
Abstract
Regeneration of black saxual (Haloxylon aphyllum) is an important project for sand dune fixation in desert area of Iran. Success of this project is largely depending on climate conditions and soil physical properties. In order to determine some inhibitor factors of black saxual growth, a project were ...
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Regeneration of black saxual (Haloxylon aphyllum) is an important project for sand dune fixation in desert area of Iran. Success of this project is largely depending on climate conditions and soil physical properties. In order to determine some inhibitor factors of black saxual growth, a project were conducted in a 2 ha black saxual site in Semnan, Iran. Morphological traits as: plant height, canopy cover, collar diameter and collar first sympodial interval and growth index were recorded on 5 year old shrubs. At the mean time soil properties as: EC, pH, SP and Texture (silt, clay, sand), were measured. The relationships among plant growth indices and soil properties showed a negative correlation (P£0.05) between growth index and saturation percent (SP). It was concluded that SP factor was the most important factor to inhibit black saxual growth in Semnan province, Iran
Aliasghar Naghipour Borj; Ghasemali Dianati Tilak; Hosein Tavakoli; Maryam Haidarian Aghakhani
Volume 16, Issue 3 , December 2009, , Pages 375-385
Abstract
Climate change and increase of global warming is one of the most important challenges in sustainable development, which is due to increase of concentration of greenhouse gasses in atmosphere. CO2 is the main part of greenhouse gasses. In order to mitigate atmospheric CO2 and create balance in greenhouse ...
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Climate change and increase of global warming is one of the most important challenges in sustainable development, which is due to increase of concentration of greenhouse gasses in atmosphere. CO2 is the main part of greenhouse gasses. In order to mitigate atmospheric CO2 and create balance in greenhouse gasses, atmospheric carbon must be absorbed and sequestrated in different forms. Rangelands ecosystems have approximately half of the worldٰs land area and they store over third of trrestrial biospher carbon. In order to evaluate the effect of grazing intensity on content and distribution of soil carbon sequestration and plant biomass, a study was carried out at Sisab semiarid rangelands of North Khorasn province. After survey, three sampling area has been specified (reference, key and critical). The content of above ground and under ground biomass carbon, litter carbon and soil organic carbon (in two depths 0-15, 15-30 cm) was determined in three area. The result showed that the total carbon sequestration in reference area was 39.79 ton/ha, in key area was 28.97 ton/ha and in critical area was 24.43 ton/ha. The results of carbon distribution showed that the soil organic carbon content was >97% of total carbon sequestration, In addition the carbon content in underground biomass was higher than above ground biomass. It was concluded that the grazing intensity cause to decrease of vegetation cover, content of plant biomass and decrease of carbon sequestration in soil and vegetation biomass, and soil is the most impotant sink for organic carbon storage in this rangelands.
Daruosh Ghorbanian; Sudabeh korouri; Parvin Salehi; Amar Rafiei Emam; Mohammad Mousavi
Volume 15, Issue 4 , January 2009, , Pages 525-539
Abstract
This project was done as a part of ecological and phonological studies of Haloxylon sp. This study was done in artificial habitat (Mohsenabad in Garmsar) and natural habitat (Chahjam in Shahrood) of Haloxylon sp. General information about condition of Haloxylon sp. habitats was gathered. Haloxylon ...
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This project was done as a part of ecological and phonological studies of Haloxylon sp. This study was done in artificial habitat (Mohsenabad in Garmsar) and natural habitat (Chahjam in Shahrood) of Haloxylon sp. General information about condition of Haloxylon sp. habitats was gathered. Haloxylon stands were examined from different points including viability of seeds, dry matter in green, yellow and green- yellow stands. Phonological studies were done. In addition, soil physical and chemical properties were determined. Results indicated the direct and significant effect of precipitation and temperature on growth of Haloxylon sp. The other important factors were insufficient amount of major elements, unsuitable texture, the low distance between stands that caused strong competition between trees to get nutrients. The presence of rare green stands indicated their genetical resistance. It seems that the origin of these stands are form central desert region of Iran.
Daruosh Ghorbanian; Mohammad Jafari
Volume 14, Issue 1 , January 2007, , Pages 1-7
Abstract
In this study one site with good coverage of Salsola rigida species selected in desert region of Shahrood area. Four plots of 100 m2 were chosen in this site and two soil profiles were digged in each plot; one profile under Salsola rigida plants and another in the space between this species. Soil samples ...
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In this study one site with good coverage of Salsola rigida species selected in desert region of Shahrood area. Four plots of 100 m2 were chosen in this site and two soil profiles were digged in each plot; one profile under Salsola rigida plants and another in the space between this species. Soil samples were collected from three depth of 10-25 cm, 10-25 cm and>25cm. For asessing elements of biomass and their effects on the soil, plant sample were analysed in laboratory. Results indicated that organic matter percentage as well as N, K and HCO3 increased significantly. An increase of Ec, Caco3 and Na are the main detrimental factors for expanding Salsola rigida species.
Mohammad Jafari; Fatemeh Panahi; Hasan Ahmadi; Hamid reza Abbasi; Mohammad Musavi; Mohammad ali Zare; Ali Tavili
Volume 13, Issue 3 , February 2006, , Pages 278-283
Abstract
The desertification phenomenon with all the problems it causes , most great effect will remain in soil, so by assessing soil variations we can reach the intensity of desertification. In the Iranian model for desertification assessment some indices including EC, soil depth, soil texture and the amount ...
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The desertification phenomenon with all the problems it causes , most great effect will remain in soil, so by assessing soil variations we can reach the intensity of desertification. In the Iranian model for desertification assessment some indices including EC, soil depth, soil texture and the amount of subsoil gravel are recommended in order to assess the intensity of desertification. Here, we chose fields in different environments such as Soleyman, low desertification risk, Gazeran, desertification risk & Hossein Abad Mish Mast, already desertified field. We selected 5 profiles in each station and studied topsoil and subsoil layers in each profile and measured soil’s physical and chemical properties in the laboratory. We used spilt plots design to regard different properties of soil in each station in topsoil and subsoil and their effects on each other. In order to appoint the desertification potential in each area and in each soil unit we used the formula following: where x is score of soil indicator and x are scores of Ec, depth, and texture and subsoil gravel rate. The obtained results based on this formula indicate that the desertification of each area is moderate. Statistical analysis showed a meaningful difference for gravel and texture. The results of Duncan test selected Soleyman and Gazeran stations in one unit subset. The method used here is designed according to soil information bank and apt to arid and semiarid climate. Of its defects we can point the unreality of its scoring because there is just 4 degrees for the intensity of desertification which limits the range of scoring. Certainly in order to evaluate the desertification phenomenon we should match the results with other sections’ results. Their results will help to precede the desertification evaluation and present indices fit to Iran pattern and conditions.
Javad Torkan; Hosein Arzani
Volume 9, Issue 2 , September 2001, , Pages 605-618