Esfandiar Jahantab; reza yari; Yaser Ghasemi Aryan; Maryam Saffari Aman; Hadi Moadab
Volume 29, Issue 3 , October 2022, , Pages 161-170
reza yari; Gholamali Heshmati; Hamed Rafiee
Volume 28, Issue 4 , November 2021, , Pages 745-758
Abstract
Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly ...
Read More
Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly important as one of the ways to reduce the pressures on people. The development of ecotourism to conserve natural resources should be commensurate with the natural and social potential of the region. Due to the importance of conserving natural resources, the purpose of this study is to evaluate the ecotourism potential of Chaharbagh summer rangelands in Golestan province based on the FAO limiting method and using GIS. The factors assessed include two ecological categories (climate, altitude, slope, soil, water resources, distance to attraction places, value attractive vegetation) and infrastructure (distance to city, amenities, roads, and access routes). The results showed that the total area of the region is 25.36% (2249.29 ha) with medium potential and competence (S2), 28.65% (2542 ha) with low potential and competence (S3), and 45.98% (4079) hectare lacks ecotourism competence and potential (N). The results also showed that water resources, soil, slope percentage, vegetation attraction value, access routes, and distance to attractions are factors that reduce the potential and merit of tourism and altitude factors, distance to city and facilities, welfare as well as climate (temperature) are factors that increase the potential and merit of tourism. Chaharbagh rangelands have suitable facilities and potentials in terms of tourism, and observing the principles of tourism and preserving natural resources, in addition to creating employment and income for the residents of the region, can help the protection and sustainable development of the region.
Maliheh Keyghobadi; Hossein Piri Sahragard; Mohammad Reza Pahlavan Rad; Peyman Karami; reza yari
Volume 27, Issue 3 , October 2020, , Pages 561-576
Abstract
Species distribution models (SDMs) are the basis of informed decisions in vegetation management by quantifying the relationship between species distribution and influential environmental variables. The present study aimed to evaluate the GAM and CART models' performance in estimating ...
Read More
Species distribution models (SDMs) are the basis of informed decisions in vegetation management by quantifying the relationship between species distribution and influential environmental variables. The present study aimed to evaluate the GAM and CART models' performance in estimating the potential habitat distribution as well as recognizing the ecological needs of plant species in the Khezri rangelands of Bayaz plain of southern Khorasan. According to the regional condition and field observation, in an area of about 14500 hectares, vegetation sampling was done using the randomized-systematic method. Eighteen environmental variables including land characteristics, Normalized Difference Vegetation Index (NDVI), and salinity index were used as an estimator to generate maps of predictor variables. After modeling the habitat distribution prediction using CART and GAM methods in R 3.5.2 software, the accuracy of the models was assessed using the subsurface area (AUC) statistics. After determining the threshold by the TSS method, the continuous utility map was converted to the presence/absence map and the degree of conformity of the maps with the kappa index was calculated. Based on the results of the used models, the variables of the base level of the channels network, the vertical distance to the channels network, the depth of the valley, the wetness index, and the relative position of the slope are effective in habitat suitability for species establishment. In general, the GAM method has high accuracy in estimating the habitat distribution range of all species studied (Kappa≥ 0.9). According to the maps obtained from the GAM model, the highest and lowest potential habitats belong to S. rigida and T. serotina species. Therefore, the GAM method can be useful in accurately identifying the ecological needs of plant species and therefore their distribution useful at the local scale. As a result, it is suggested that this method be used as part of a management support system in the protection and restoration of vegetation in the rangelands of the Bayaz plain.
Reza Yari; Hosein Azarnivand; Mohammad Ali Zare Chahouki; Jalil Farzadmehr; Firoozeh Moghimi Nejad
Volume 21, Issue 2 , August 2014, , Pages 247-259
Abstract
This research was aimed to evaluate the environmental factors affecting the distribution of vegetation in Sarchah Amari ranglands, Birjand. After field visits, five vegetation types were selected based on physiognomy method and soil and vegetation sampling was done in key area of each vegetation ...
Read More
This research was aimed to evaluate the environmental factors affecting the distribution of vegetation in Sarchah Amari ranglands, Birjand. After field visits, five vegetation types were selected based on physiognomy method and soil and vegetation sampling was done in key area of each vegetation type along the transect and within square plots with systematic-random method. Depending on the type and distribution of plant species, the plot size was calculated to be 1.3 and 16 m2 and 45 plots were established in each vegetation type along transects. The percentage of vegetation cover was measured in all plots but soil sampling was done in the first and last plots of each transect at soil depths of 0-30 and 30-80 cm. Soil characteristics including soil texture, percentage of lime, saturated moisture, gypsum, pH, electrical conductivity, sodium, calcium, potassium, magnesium, chlorine and topographic features including slope, aspect and altitude above sea level were measured. Soil and vegetation data were analyzed by PCA and ANOVA. The results of PCA showed that among the environmental factors, EC, the percentage of sand, slope, gypsum, organic matter and the soluble sodium were the most important environmental factors affecting the distribution of vegetation. Overall, these factors could explain 89.73% of the vegetation distribution. The results of ordination (PCA) showed that 70.74% and 18.63% of vegetation distribution were explained by the first and second axes, respectively. The first axis variables included the percentage of sand, electrical conductivity (EC), percentage of gypsum, sodium and the organic matter of first depth. According to the algebraic sign of variables, the distribution of vegetation was positively correlated with the percentage of sand while it showed a negative correlation with electrical conductivity (EC), gypsum, sodium and organic matter in first depth. The second axis variables of the ordination diagram included the percentage of slope and organic matter of second depth and according to the algebraic sign of variables, the distribution of vegetation had a negative correlation with the percentage of slope and soil organic matter of second depth.
Hosein Azarnivand; Yaser Ghasemiaryan; Reza Yari; Mohammad Ali Zare Chahouki; Esfandyar Jahantab
Volume 19, Issue 2 , September 2012, , Pages 297-305
Abstract
The aim of this study was to investigate allelopathic activity of aerial and underground organs of mountain sagebrush (Artemisia aucheri) on seed germination features, root length, shoot length and seed vigor of Festuca ovina.For this purpose, species of mountain sagebrush were collected from Taleghan ...
Read More
The aim of this study was to investigate allelopathic activity of aerial and underground organs of mountain sagebrush (Artemisia aucheri) on seed germination features, root length, shoot length and seed vigor of Festuca ovina.For this purpose, species of mountain sagebrush were collected from Taleghan rangelands in Tehran Province and then were dried in direct sunlight and grinded.Powder derived from aerial and underground organs to the amounts of 3, 6 and 9 grams were separately mixed with 900 grams of sand in completely randomized blocks with four replications. In each pot, 10 seeds were planted at a depth of 2-3 cm. Germination percentage, germination velocity, seed vigor, root length, and shoot length were measured. Data analysis was performed using MSTATC software and mean comparisons were carried out using Duncan's test. Results showed that there were no significant differences among measured factors. Also, the shoot and root lengths showed significant differences at probability levels of 5% and 1%, respectively. According to the results, Artemisia aucheri caused a reduction of root length in Festuca ovina.
Reza Yari; Ali Tavili; Salman Zare
Volume 18, Issue 4 , September 2012, , Pages 624-636
Abstract
Management activities like crescent intake and enclosure affect the soil surface indicators and rangeland functional attributes. To have a continuous and sustainable utilization of rangelands these changes must be recognized and managed. Indicators of soil surface characteristics and rangeland functional ...
Read More
Management activities like crescent intake and enclosure affect the soil surface indicators and rangeland functional attributes. To have a continuous and sustainable utilization of rangelands these changes must be recognized and managed. Indicators of soil surface characteristics and rangeland functional attributes assist researchers in judging the effects of their applied management activities. The aim of this study is to investigate the effects of management activities like crescent intake and enclosure on soil surface indicators and rangeland functional attributes. For this purpose, three regions including freed enclosure, enclosure and crescent intake were selected and the effect of any aforementioned activities on soil surface characteristics and rangeland functional attributes were investigated by using Landscape Functional Analysis (LFA) method. In this method, for determination of three functional attributes (stability, infiltration and nutrient cycle) 11 soil surface indicators were applied as follows: ground cover, litter cover, litter (degree of decomposition), cryptogam cover, soil surface resistance to distribution, eroded materials, erosion features, soil microtopograghy, soil surface nature, slake test and soil texture. Data analysis was performed with SPSS software, Kruskal-Wallis nonparametric test and a Duncan multiple range test. According to the results, the indicators and functional characteristics of the rangeland have been changed due to the management activities. As significant differences were found among all 11 soil surface indicators except erosion feature and cryptogam cover in three studied regions (P<0.05). Also significant differences were found among three rangeland functional attributes in three study areas. Our results indicate that crescent intake and enclosure could improve rangeland functional attributes.
Reza Yari; Hosean Azarnivand; Mahammad ali Zare Chahouki; Jalil Farzadmehr
Volume 19, Issue 1 , June 2012, , Pages 95-107
Abstract
In this study, the relationship between species diversity and environmental factors in the pastures in the Sarchah Amari ranglands of Birjand was investigate. For this purpose, after classification of vegetation types through physiognomy method, sampling from vegetation and environmental factors were ...
Read More
In this study, the relationship between species diversity and environmental factors in the pastures in the Sarchah Amari ranglands of Birjand was investigate. For this purpose, after classification of vegetation types through physiognomy method, sampling from vegetation and environmental factors were accomplished in the key area of each vegetation type by random-systematic sampling. Plot size and the number of plots were respectively determined by minimal area and statistical methods. Afterward, in the key area of each vegetation type, three 300 m transects were established and 15 plots with 20 m intervals were located along each transect. Sampling of vegetation was carried out in all plots while soil samples were taken at the beginning and end of each transect from two depths of 0-30 and 30-80 cm. The list of plant species and canopy cover percentage were recorded in each plot. Percentage of soil gravel, clay, silt, sand, moisture saturation, pH, lime, organic matter, gypsum, electrical conductivity and soluble salts (sodium, potassium, chloride and magnesium) and topographic features (slope, aspect and altitude) were measured. For data analysis, species richness and evenness were calculated using different diversity indices (Simpson and Shannon -Wiener index of heterogeneity, Kamargov and Smith- Wilson as the homogeneity index). To determine the most important factors influencing variations of species diversity, principal components analysis was used. The results showed that electrical conductivity, gypsum, organic matter, slope, and sand were the most effective factors on diversity in the study area.
Asghar Farajollahi; Mohammad ali Zare Chahouki; Hosein Azarnivand; Reza Yari; BahraM Gholinejad
Volume 19, Issue 1 , June 2012, , Pages 108-119
Abstract
In this study, the relationship between environmental factors and distribution of plant communities in rangelands of Bijar protected region was investigated. Vegetation types were determined by using physiononmy method. Plot size was determined with minimal area method and after primary sampling the ...
Read More
In this study, the relationship between environmental factors and distribution of plant communities in rangelands of Bijar protected region was investigated. Vegetation types were determined by using physiononmy method. Plot size was determined with minimal area method and after primary sampling the number of plots was determined by statistical method. In each vegetation type, sampling was done along four transects of 300 m length. 15 plots of 1m2 were established along each transect at 20 meter intervals. The type and the amount of existing species and the percentage of vegetation cover were determined in each plot. In each community, 6 profiles were dug within sampling unit. Soil samples were taken from 0-20 and 20-100 cm according to the boundary of separated horizons and type of existing plant species in study area. physiographic features including altitude, slope and aspect were measured and among soil properties, clay, silt, sand, lime, pH, EC, organic mater and gravel were measured. After collecting data, the Principal Component Analysis (PCA) was used to determine relationship between vegetation cover and environmental factors by PC-ORD software. The results indicated that there were relationships between measured factors and distribution of vegetation. Texture, gravel, lime, altitude and slope had the most influence on distribution of plant communities.
Ali Tavili; Salman Zare; Reza Yari
Volume 17, Issue 3 , October 2010, , Pages 466-475
Abstract
Nowadays, with regard to the global view of desert issue and necessity of using adaptable species in combat desertification, it is urgent to identify and remove the constraints of their production and establishment. Ammodendron persicum is one of the important and compatible species in desert ecosystems. ...
Read More
Nowadays, with regard to the global view of desert issue and necessity of using adaptable species in combat desertification, it is urgent to identify and remove the constraints of their production and establishment. Ammodendron persicum is one of the important and compatible species in desert ecosystems. The current research was carried out to investigate the effect of different treatments on seed dormancy breaking and germinationstimulation ofAmmodendron persicum in order to determine the most effective treatment in enhancing of germination and primary growth of seedlings .The experiment was done in a Randomize Complete Block Design (RCBD) with 8 treatments and 4 replications. Different treatments were applied including scarification plus sulphuric acid (H2SO4 98%) for 10 and 15 minutes, scarification with sandy paper, scarification plus putting the seeds in hot water for 10 and 15 minutes, KNO3 (0.1 and 0.2 %), a complex treatment of scarification and KNO3 (0.1 and 0.2%) and distilled water as control treatment .To analyze the data, ANOVA was used and Duncan test was applied to compare the means. The result showed that scarification with sandy paper had the highest effect onseed dormancy breaking and seed germination stimulation of A. persicum as germination percentage increased from 3% in distilled water to 68% in scarification treatment.