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 ...
Read More
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.
Javad Momeni Damaneh; Yahya Esmaeilpour; Hamid Gholami; Azita Farashi
Volume 28, Issue 3 , October 2021, , Pages 578-592
Abstract
Ferula assa-foiteda L., as one of the most important range plants in northeastern Iran, plays an important role in soil conservation and the economy of rangeland stockholder. However, misuse and destruction of its habitats are among the factors threatening this natural capital. This study was conducted ...
Read More
Ferula assa-foiteda L., as one of the most important range plants in northeastern Iran, plays an important role in soil conservation and the economy of rangeland stockholder. However, misuse and destruction of its habitats are among the factors threatening this natural capital. This study was conducted to identify potential habitats of this species in the two provinces of Khorasan Razavi and North Khorasan, which can be a step towards to facilitate and develop replanting and rehabilitation operations of this species. Spatial data of the presence of this species with a pixel size of 1100 × 1100 m were used as actual suitable places for its growth and layers of environmental information such as climate, soil, geology and physiography were used as predictor variables. First, in Biomaper Version 4, the correlation of prediction variables was examined and independent variables were selected. The potential habitat areas extracted from the species distribution model mapped with the Maxent 3.3 software. The results showed that the used model had good accuracy and reached to AUC of 0.97. In terms of significance, the study of input variables to the model using the Jackknife test showed that, respectively, land unit components, seasonal temperature, geological formation, dominant land slope, habitat height and daily average temperature are suitable for the potential habitat of Ferula assa-foiteda L. species in the level of the study area is of the utmost importance. The results of this study can be used to identify the ecological needs of the species (Ferula assa-foiteda L.) and to develop and rehabilitate their habitats.
Maryam Mirdailamy; Mohammad Rahimi; Shima Nikoo; Ali Akbar Damavandi
Volume 27, Issue 1 , April 2020, , Pages 58-74
Abstract
In the past four decades, land use changes in Iran, have become more frequent as a human desertification factor, which has led to an intensification of land degradation in all types of land uses. In this research, due to the wide range of these changes, we used remote sensing technology to assess land ...
Read More
In the past four decades, land use changes in Iran, have become more frequent as a human desertification factor, which has led to an intensification of land degradation in all types of land uses. In this research, due to the wide range of these changes, we used remote sensing technology to assess land use and vegetation changes in Damghan plain. The area of the study region was classified into three classes including unutilized land, lands with vegetation cover (agriculture and pasture) and urban areas using supervised classification strategy and the changes of the land uses were compared over four periods. The results indicated an increase of 184% and 1.07% respectively in urban land use and unutilized land use and a 15.7% reduction in lands with vegetation (agriculture and pasture). Using the Normalized Difference Vegetation Index(NDVI), the results of classification of vegetation in the region were such that class 1 (index less than zero), from 93.3 to 99.5 percent increase, class II( Between 0 and 0.2), from 5.6 to 0.38 percent, and the third class (index ranging from 0.2 to 0.5), from 1.1 to 0.01 percent, and class four (index ranging from 0.5 to 1) has changed from 0.03 to 0%, which indicates the validity of the findings from the review of the changes in land use, both of which indicate an increase in dry land and a decrease in vegetation. Also by using the Iranian model's climatic indices, the potential of desertification, the results of the 17-year calculations during the period of 1997 to 2013 indicated that desertification had decreasing trend in three classes: weak, severe and very severe, and increasing trend in the middle class. Finally, by combining the findings from the Iranian model and the results of remote sensing method, a weak trend in desertification based on climate criteria in the region was confirmed.
Kian Najafi Tireh Shabankareh
Volume 11, Issue 1 , September 2019, , Pages 83-112
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 ...
Read More
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.
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 ...
Read More
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.
Ghader Karimi; Hasan Yeghaneh; Hasan Barati; Farhang Ghasriani
Volume 21, Issue 4 , March 2015, , Pages 631-642
Abstract
A proper utilization of rangelands could result in preventing degradation, maintaining desirable species and improving range condition, leading to longterm and economic production. This research was aimed to investigate the allowable use of Stipa hohenckeriana in Kordan rangelands. In this study, a reference ...
Read More
A proper utilization of rangelands could result in preventing degradation, maintaining desirable species and improving range condition, leading to longterm and economic production. This research was aimed to investigate the allowable use of Stipa hohenckeriana in Kordan rangelands. In this study, a reference area of one hectare was selected and fenced in the first year of the study. Treatments included four harvesting intensities of 25, 50 and 75% and 0 (control group). Finally, data were analyzed using split plot design in time with 10 replications for each treatment. Data analysis was performed by SAS software. Results showed that the effects of harvesting intensity, different years and their interactions on the forage production were significant at 1% level of probability, indicating that in different years, production rate varied with varying climate conditions. According to the results, an allowable use of 25% is recommended for Stipa hohenckeriana in the study area. The recommended allowable use can be used in determining the allowable use for the study area and areas of similar climate, along with information from other plants.
Ali Ehsani; Hosein Arzani; Mahdi Farahpoor; Hasan Ahmadi; Mohammad Jafari; Adel Jalili; Hamid Reza Mirdavodi; Hamid reza Abbasi; Mojgan Azimi
Volume 14, Issue 2 , January 2007, , Pages 249-260
Abstract
The effects of climatic factors on four dominant range land species of Markazi province, Iran, were studied. Species were Artemisia sieberi, Salsola rigida, Noaea mucronata, Stipa barbata and were monitored from 1998 to 2005. Site is located in steppe lands and called Nemati range, Akhtarabad of Saveh. ...
Read More
The effects of climatic factors on four dominant range land species of Markazi province, Iran, were studied. Species were Artemisia sieberi, Salsola rigida, Noaea mucronata, Stipa barbata and were monitored from 1998 to 2005. Site is located in steppe lands and called Nemati range, Akhtarabad of Saveh. Climatic factors were annual rainfall, rainfall of grazing season plus rainfall of previous year, temperature, solar radiation and wind velocity. Among the main indicators, as results shows, growing season plus previous rainfalls is the most effective indicator on forage production with high and significant correlation. Total yield have positive and significant correlation with growing season rainfall and previous rainfall as well as production of Artemisia sieberi, Salsola rigida. Soil and water regime in dry and semi-dry areas, in growing season, is in a way that plants are dependent on stored moisture. Shrubs, with their deep roots, are more capable of using this moisture. Therefore stored moisture could be known as an indicator of rain quantity. Result of this research showed that rainfall indicator in growing season and previous season is a variable that plays fundamental rule in production, showing a linear relationship. Negative correlation was shown between number of sunny days, total yield and yield of two species, Salsola rigida and Artemisia sieberi.
Javad Torkan; Hosein Arzani
Volume 9, Issue 2 , September 2001, , Pages 605-618