Ali Ehsani; Hosein Arzani; Mahdi Farahpur; Hassan Ahmadi; Mohammad Jafari; Mortezah Akbarzadeh
Volume 19, Issue 1 , June 2012, Pages 1-16
Abstract
In this study, potential and actual evapotranspiration were estimated by Penman- Matis using climatic data of Saveh Station, and plant and soil characteristics were estimated by Cropwat 8.0 software. Our results showed that potential evapotranspiration in growing season was 6.16 times greater than the ...
Read More
In this study, potential and actual evapotranspiration were estimated by Penman- Matis using climatic data of Saveh Station, and plant and soil characteristics were estimated by Cropwat 8.0 software. Our results showed that potential evapotranspiration in growing season was 6.16 times greater than the average of actual evapotranspiration. Actual evapotranspiration was 1.18 times greater than the average precipitation of growing season. It means that plant species have used the stored moisture for actual evapotranspiration. According to the estimation of actual evapotranspiration in a ten-year period, a model was provided for forage production as Ya= 74.30+ 2.698 (ETact). Accordingly, average forage production of the studied site was estimated as 257 kg/hec. It could be said that actual evapotranspiration as an index for climate yield is one of the fundamental factors in improving water use efficiency. Application of the mentioned climate index in different estimation models of long term forage production could be considered in order to determine the rangeland grazing capacity and developing rangeland insurance as a replacement for the usual methods of production.
Tayebeh Sohrabi; GHolamreza Zehtabian
Volume 19, Issue 1 , June 2012, Pages 17-31
Abstract
Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources ...
Read More
Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources and agriculture and annually huge amount of our water and soil resources are degraded. Since the advent of the farming activities until the present, human needs have been based upon farming activities. Considering the growing population and the social and economic developments, most of rangelands have been subject to rainfed cultivation. Therefore, to prevent further degradation of soil in these regions research should be conducted on agricultural lands and the exploitation methods. For this reason, Taleghan was selected as the study area. Map of the area, including soil maps, land types and the current land use were produced by GIS. After determining the main treatments, soil samples were taken in every part of the area and in agricultural area and soil factors were measured within two groups of soil improvement factors including nitrogen, phosphorus, potassium, humus and lime and soil degradation factors including acidity, sodium adsorption ratio (SAR) and salinity in two depths of 0-10 and >10 cm. These factors were studied in a split-plot design. The results showed significant differences among treatments. According to the results of soil improvement and degradation factors, orchards and rangelands are in an ideal condition and monoculture treatment decreases the performance of the products.
Esmaeil Sheidaye Karkaj; Javad Motamedi; Kayvan Karimizadeh
Volume 19, Issue 1 , June 2012, Pages 32-44
Abstract
Suitability of rangeland application in watersheds for optimum use of land is of particular importance which is done with using systemic analysis method. In this method, ecological capability of land is determined for each common land uses. Therefore, in Khanghah Sorkh watershed, homogenous unites ...
Read More
Suitability of rangeland application in watersheds for optimum use of land is of particular importance which is done with using systemic analysis method. In this method, ecological capability of land is determined for each common land uses. Therefore, in Khanghah Sorkh watershed, homogenous unites were determined after identifying the ecological resources and then land capability for rangeland use was assessed in whole watershed. According to the results, 18 ecological homogenous units were distinguished in a scale of 1:25000 as large parts of the lands were devoted to the land use classes of 2-3. Potential and actual ecological land capability of the study area was low for class 1 of rangeland use. In this regard, 24 percent of the land, in terms of geological structure, especially due to the sharp slope, was considered as ecosystem conservation and was offered for wildlife grazing. Meanwhile, 3.8 percent of the rangeland was determined as class1, 11 percent class2, and 19 percent class3. Accordingly, balanced range management and natural range management methods are respectively offered for 3.8 percent (76 ha) of rangelands in the watershed with class 1, and 54.6 percent (1091 ha) with classes 2 and 3. Range improvement practices or artificial range management method is also offered for 41.7 percent (833 ha) of the lands in order to convert inefficient dryland farming to cultivated rangelands.
Jallal Abdolahi; Hossean Arzani; Mohammad hosein Savaghebi; Mojgan Azimi; Hosein Naderi
Volume 19, Issue 1 , June 2012, Pages 45-59
Abstract
Our country’s rangelands are mainly located in arid and semi-arid regions. Due to the low amount of precipitation and high rate of evapotranspiration, water stress is considered as the most crucial environmental stress for vegetation in this region. This study was conducted at Khud-e-sofla ...
Read More
Our country’s rangelands are mainly located in arid and semi-arid regions. Due to the low amount of precipitation and high rate of evapotranspiration, water stress is considered as the most crucial environmental stress for vegetation in this region. This study was conducted at Khud-e-sofla rangelands for nine years (1378- 1386) to investigate the effect of precipitation fluctuation on canopy cover and production of important plant species. For this purpose, four dominant species were selected and their canopy cover and production were monitored every year in permanent and random plots, respectively. Precipitation data were collected from the nearest synoptic station. According to the data of precipitation, cumulative rain amount was calculated at various periods. The relationship between variables of plant parameters and cumulative rain amount was analyzed by step wise regression method in SPSS 13. The results showed that plant species often reacted to the precipitation fluctuations. However, various species reacted differently to the precipitation fluctuation in terms of cover and production. The total vegetation cover as well as canopy cover of Artemisia aucheri hada negative and significant correlation with winter precipitation.Whereas, precipitation of January to April and the past year precipitation exhibited a high correlation with canopy cover of Iris songarica and Stipa barbata. The forage production was also influenced by seasonal precipitation. According to the results, total yeild and the yield of Artemisia aucheri, Lactuca orientalis, Stipa barbata could be estimated by precipitation data While, estimation of forage production through the precipitation data was not enough accurate for Iris songarica.
Sadigheh Mohammadi; Ali Salajegheh; Mohammad Mahdavi; Reza Bagheri
Volume 19, Issue 1 , June 2012, Pages 60-71
Abstract
Due to the variation of ground water properties in temporal and spatial scale, these properties can not be assumed constant over time and space. This research was conducted to assess spatial and temporal variations of ground water table in Kerman plain during a 10-year period (1375-1385) by using the ...
Read More
Due to the variation of ground water properties in temporal and spatial scale, these properties can not be assumed constant over time and space. This research was conducted to assess spatial and temporal variations of ground water table in Kerman plain during a 10-year period (1375-1385) by using the best geostatistical estimator. Firstly, available statistical resources related to the ground water table of this plain (including 67 wells) were collected. After controlling for quality, accuracy and normality of the data, different interpolation techniques were used including kriging (with and without logarithm), cokriging, inverse distance (with exponents of 1 to 5). The best technique was selected based upon MAE and MBE criteria and provided spatial zonation maps in the beginning and end of the period. Spatial zonning maps were prepared at the beginning and end of the study and ultimately, iso-falling map was provided in Arc GIS 9.1 package. Our findings showed that Gaussian variogram model was the best for spatial structure of these data and inverse distance method with exponents of 5 and 4 were the best interpolation methods in the beginning and end of the period, respectively. Zonation maps showed a falling trend of the ground water level in majority of the plain. Maximum falling data (32 meters), was recorded respectively for the northern outlet of the plain with an effective range of 17 and 62 pizometers and western outlet with an effective range of 8 pizometers. Also, the results showed an upward trend of water, as 7 meters, in effective range of some wells with 50 and 52 pizometers in Kerman city due to being located in sewage and waste water zone of the city.
Rasool khatibi; Yaser Ghasemi Arian; Esfandyar Jahantab; Mohammad Haji hashemi
Volume 19, Issue 1 , June 2012, Pages 72-81
Abstract
Soil properties are of the effective factors in distribution of vegetation, especially in arid and semi arid regions as the effect of geology, topography and climatic factors appeare in soil properties. In this study, soil properties of rangeland vegetative types was studied in Dejinak-e-Khash in the ...
Read More
Soil properties are of the effective factors in distribution of vegetation, especially in arid and semi arid regions as the effect of geology, topography and climatic factors appeare in soil properties. In this study, soil properties of rangeland vegetative types was studied in Dejinak-e-Khash in the southern of Taftan. Soil and vegetation sampling were done in key areas of each site by random- systematic method. Plot size was determined with minimal area method. Also, the size and number of transects for sampling were determined according to species and vegetation changes. Physicochemical properties of soil including soil texture, pH, electrical conductivity, lime and organic matter were measured. After measuring soil and plant factors, statistical analysis was performed on plant species, vegetation types and soil factors by SPSS software. Finally, the best equation and correlations were determined between vegetation types and soil parameters. Results showed that the percentage of organic matter, clay and absorbable potassium were the most important factors in distribution of key range species in the study area. In general, the results showed a significant relationship at 95% probability level for Artemisia siberi with potassium and clay, for Salsola nitraria with soil pH, and for Acanthophyllum microcephalum with total nitrogen. Also, the distribution of Hammada salicornia was significantly affected by all factors except P and EC at 95% probability level.
Mirtaher Ghaemi; Mortezah Akbarzadeh; Shahram Abedi
Volume 19, Issue 1 , June 2012, Pages 82-94
Abstract
Study of exclosure effects on vegetation changes under grazing and no grazing conditions in rangelands is of particular importance in range improvement programs. The reseach was performed in Semi- Steppe area of Bilehvar, Khoy from 1998 to 2006 . The vegetation cover was measured every year inside fixed ...
Read More
Study of exclosure effects on vegetation changes under grazing and no grazing conditions in rangelands is of particular importance in range improvement programs. The reseach was performed in Semi- Steppe area of Bilehvar, Khoy from 1998 to 2006 . The vegetation cover was measured every year inside fixed plots along the transacts. The results indicated the increase of total canopy cover inside the exclosure occurred during 9 years of the study, where the highest increase rates were observed with perennial cereals (>3.5 times), and with perennial broad-leaf forbs (>2.5 times). Outside the exclosure, the total canopy cover approximately remained unchanged and vegetative forms showed less changes. Inside the exclosure, favorable species appeared with a vegetation composition of about 19% . The proportion of increasers in the vegetation composition increased to more than double, however non-favorable species decreased to half. Outside the exclosure, desirable species were rare and the proportion of increasres increased to 28%. Average vegetation cover of annual plants inside the exclosure was higher than that of the outside, while average vegetation cover of the forbs compared to annual cereals were more predominant inside and outside the exclosure. During the study (9 years) in Bilehvar, a significant correlation was found between precipitation changes and canopy cover of the most species.
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.
Hosein Babazadeh; Elnaz Norouzi Aghdam; Hosein Aghighi; S.Amir Shamsnia; Davud Khodadadi dehkordi
Volume 19, Issue 1 , June 2012, Pages 120-132
Abstract
Soil surface moisture and it's spatial and temporal variability is one of the most importantenvironmental variables. Due to the difficult, costly and time consuming measurements of field studies, this parameter has not been used widely in climate models. Nowadays, with the increasing development ...
Read More
Soil surface moisture and it's spatial and temporal variability is one of the most importantenvironmental variables. Due to the difficult, costly and time consuming measurements of field studies, this parameter has not been used widely in climate models. Nowadays, with the increasing development of science, adoption of new technologies for proper management of limited water and soil resources is necessary. The objective of this research was to analyze the application of MODIS images for estimating the soil surface moisture in arid and semiarid rangelands with ephemeral vegetation cover using TVX. Field data measurments of soil surface moisture and some daily meteorological parameters in three station of Mashhad, Golmakan and Neyshaboor of Khorasan province were used for more accurate estimate of soil surface moisture from 2003 to 2005. NDVI, Brightness Temperature of the bands (BT31, BT32) and Land Surface Temperature (LST) were derived from MODIS images and TVX slope was calculated. Different regression models were fitted to assess the relationship between TVX slope and soil surface moisture. According to the results, soil surface moisture in arid and semiarid climate showed a good correlation with TVX slope.
Seyed Jafar Seyed Akhlaghi; NaseR Ansari; Saeid Yusof Kalafi
Volume 19, Issue 1 , June 2012, Pages 133-148
Abstract
Although the factors affecting the degradation of natural resources have been more or less identified and introduced, little research has been done on these factors from the view point of socio economic and cultural features. It seems that before any action, degradation of natural resources ...
Read More
Although the factors affecting the degradation of natural resources have been more or less identified and introduced, little research has been done on these factors from the view point of socio economic and cultural features. It seems that before any action, degradation of natural resources must be stopped through a cessation program for natural resources degradation. This research was based upon documental, field and desk research method through three types of study including documents surveying, collecting information and field study using observation, companionship and questionnaires in Ardebil province. Ten sampling regions with a surface area of 122020 ha including 68 rural and nomad settlements and 273 households were selected. Our results showed that totally 19 main factors in three groups of livestock (45.9 %), harvesting (20.6 %) and land use change (33.5 %) were effective in degradation of natural resources of Ardebil province. In this research, determination of the destructive factors on the basis of separate vegetation regions gave valid results for natural resoures provincial managers
Ebrahim Farahani; Amrali Shahmoradi; Samira Adibi
Volume 19, Issue 1 , June 2012, Pages 149-158
Abstract
Stipa hohenackeriana Trin & Rupr is a perennial plant of the gramineae family. This species covers a wide range of habitats in Tehran province. The habitat characteristics of this species including topography, climate, vegetation type, soil, associated species, plant phenology and root system were ...
Read More
Stipa hohenackeriana Trin & Rupr is a perennial plant of the gramineae family. This species covers a wide range of habitats in Tehran province. The habitat characteristics of this species including topography, climate, vegetation type, soil, associated species, plant phenology and root system were investigated. The results showed that these habitats were located in altitudes of 880 to 2400 m above sea level. The average rainfall in the habitats was 150 mm to 378 mm. The annual average temperature, annual minimum temperature and annual maximum temperature were 15.5 to 24.4°C, -2 to 12°C and 32 to 42 °C, respectively. This plant was observed in a range of shallow to very deep soils at slopes of more than 0.5 percent. Soil acidity measurement showed levels of 8.1 to of 8.71 and the electrical conductivity of the soil were 0.19 to 0.98 ds/m. In most habitats, this species has emerged as the dominant. Average canopy cover, density and frequency were 8.43%, 9050 plants / ha and 90%, respectively. The ratio of root to shoot weight was 0.226. This plant has a highly branched root system. Phenology of the species in different habitats showed that the growth started from mid-March to mid April. Production stage of pods was in late May. Flowering was from late May to late June. Seed production occured from late May to late July. According to regional climatic conditions, the seeds were matured .From early September to early October the plant was in summer dormancy. This study showed that chemical compounds of crude protein and crude fat were maximum at early growth stage but gradually decreased in the coming stages.
Fazel Amiri; Hosein Arzani
Volume 19, Issue 1 , June 2012, Pages 159-177
Abstract
Rangeland evaluation is defined as identification and assessmnet of actual and potential production in order tohave a sustainable utilization ofthisvaluable resource. One of the important indirect applications in multiple use of rangelands is Apiculture. In this study, site priority for apiculture was ...
Read More
Rangeland evaluation is defined as identification and assessmnet of actual and potential production in order tohave a sustainable utilization ofthisvaluable resource. One of the important indirect applications in multiple use of rangelands is Apiculture. In this study, site priority for apiculture was investigated in rangelands of Ghareh Aghach at Semirom in order to have a sustainable utilization of these rangelands. Suitability model for apiculture was formed from integration of three criterias of vegetation cover, environmental factors and water resources availability using FAO method (1991) and Geographic Information System. Afterward, priority of the vegetation types for apiculture was determined through AHP method. Samples were randomly collected along threetransects of two hundred meters longin each vegetation type. Presence and absence, cover percentage, diversity and vegetation composition of pollen and nectar plants were measured using 1m2 quadrates. To determine the priority of the factors, question sheets were used. The results of priority indicated that apiculture suitability of the vegetation types was different. According to the results, index weight of vegetation cover factor (0.687) was more than that of environmental factors(0.244) and water resource availability (0.069). As.ad-Ag.tr-Da.mu and Co.ba-As.sp vegetation types with a weight of 0.092 showed the highest priority in terms of apiculturalwhileAg.tr with a weight of 0.028 had the lowest priority among vegetation types. Generally, the results of apiculture model showed that 29% of land units (vegetation type) was classified as high suitable (S1), 59% with moderate suitability (S2), 6% with low suitability (S3) and 6% non suitable for apiculture. Considering the suitability and priority areas for apiculture is very important in improvement of range condition.
Mostafah Zare; Mohammad Fayyaz; Gholamreza Goudarzi; Ali Farmahini farahani
Volume 19, Issue 1 , June 2012, Pages 178-190
Abstract
The preference value is defined as selection of available species by livestock in the free grazing. This study was conducted in semi steppe rangelands of Anjedan located 35 Km far from east Arak. These rangelands are of important centers for keeping livestock which is under heavy grazing with a poor ...
Read More
The preference value is defined as selection of available species by livestock in the free grazing. This study was conducted in semi steppe rangelands of Anjedan located 35 Km far from east Arak. These rangelands are of important centers for keeping livestock which is under heavy grazing with a poor condition. The soil of the study area is loamy with high stone and gravel. This study was performed to determine the preference value of important species for sheep to support palatable species in range management plans. Direct observation (timing) method was used to calculate the time spent on livestock grazing and presence during grazing season for 3 years. Afterward, data were analyzed by SAS software in a complete random block design and Duncan test was used for mean comparisons. The results showed the preference value in different season grazing months significantly differed (p<0.01). Generally, annual grasses and forbsshowed maximum preference value. Plant litters, Bromus tomentelus, Artemisia aucheri, Buffonia koelzii respectively ranked next in terms of preference value.