Journal of Rangeland Science
Volume:2 Issue: 1, Autumn 2011

Based on the importance and role of species diversity and richness as a measurement of the health of an ecosystem; studying of their components can lead to evaluate the health condition of rangeland. This research was carried out in a part of highland mountainous rangeland of Mount Alborz Range in Iran. Diversity and richness were assessed as an ecosystem health indicator. The study area was located between 2200 to 4200 m altitude in north of Iran. The rangeland vegetation was covered by grass as the dominant species along with forbs and cushion like species. The rangeland was grazed by livestock as summer rangelands. The samples were collected in reference, key, and critical areas using transects. The data were analyzed by stepwise regression in that rangeland condition as dependant variable and vegetation form as independent variables. Plant diversity and richness indices were calculated by PAST Software. The results showed that grass species diversity had the highest correlation with the rangeland condition in key site. The cushiony species and the combination of grass and forbs had high correlations with the rangeland condition in both critical and reference sites. The key and critical rangelands had the highest and lowest diversity, respectively. The critical zone was in disequilibrium conditions so the rehabilitation of vegetation cover is recommended for the similar regions. It was concluded that Long-term enclosure can decline the species diversity and richness. Moderate grazing is the best tool to use the grazing land without severe reduction in abundance and biomass of species.

Vegetation cover is the first barrier for the raindrops resulting to the interception and infiltration loss. Interception as one of the main components of ecohydrology equation plays a major role in the water balance of rangelands. However, few studies have been done on the interception of rangeland plants in Iran. This study was carried out to find the interception rate in Astragalus parrowianus through the rainfall portable simulator devices. In addition, the relationship between plant structural factors such as height, large and small diameters, volume and surface of cover and rangeland physiographic factors including altitude, slope percentage and slope in the interception rate was evaluated. Data were collected and analyzed based on simple linear regression models and multivariate analysis (stepwise approach and descending). Results showed that in first group with a volume of 0.002 to 0.02 m3 and canopy cover of 642 m2, 4.421% of total amount of rainfall interception was happened while in second group with volume of 0.02 to 0.087 m3 and canopy cover of 1640 cm2, the interception rate was 1.85% out of total precipitation. In the first group, the interception rate showed a significant correlation (P≤1%) with large diameter (r=-0.73) and the canopy cover at 5% level (r=-0.51). Interception rate in the second group at 1% significant correlations with canopy cover (r=-0.93), diverse small diameter (r= -0.874), large diameter (r=-0.76) and plant volume size was calculated (r=-0.83). From the regression equations obtained in each group, the interception rate can be measured in Astragalus parrowianus without clipping and weighing.

Range management needs information on distribution of livestock. The better the distribution of the livestock, the more uniform the use of the rangeland. This study was conducted to record the path of the herd steering by the shepherd. A GPS was attached to a three year old ewe which was moving with the flock. The path of flock movement was recorded for three years on a monthly basis during the grazing season. Results showed that the path was not changing within the years. On the contrary, the pattern of monthly movements showed variation. Area at the vicinity of the watering point and the sheep pen, as a sign of overgrazing for those areas, was used every day. Calculation of the grazed area showed that almost half of the range was used and the other half was left ungrazed. The map and attribute data such as speed of the movement and timing of the daily orbit could help the range manager to find a way out of over grazing problem.

In order to study the effects of three operations of rangelands on the properties of vegetation in rangelands, this research was conducted in Chaat Gonbad, Golestan province, Iran in 2004. Chaat area is located in 50 km of border road of Dashlibroun to Maravetappeh in North of Attract River (border of Iran and Turkmenistan). The Altitude is 70 m, annual rainfall is 170 mm and annual temperature is 8.16°C. Most of rains fall in spring. In this study, four operation systems including contour furrow, pitting, enclosures and control area (without any operations) were conducted. Samples of vegetation factors were done randomly in 20 plots of 1m2. Data were collected for the forage production, vegetation cover% and canopy height. Data were subjected to analyses of variance and comparisons were made using Duncan method. The results showed significant differences among four operation systems for all traits (P<0.01). The results showed that contour furrow had more efficiency for plant characteristics compared to other operation systems.

The diversity and richness of species are of important components to evaluate the health of ecologic system of rangelands. This research was conducted to investigate the biodiversity in riparian and neighboring areas via comparison of indices in Javaherdeh rangeland of Ramsar. Plot-transects was randomly used to estimate diversity, richness, dominance, and evenness indices in two regions. Multi Linear regression method was used to analyze the relationships of three indices to rangeland condition. Results of floristic list showed that there were 66 species belong to 19 families and 56 genera. Gramineae and Compositae families with values of (23.24 and 12.1%) had the highest and Boraginaceae and Hypolepidaceae with 2% had the lowest frequency, respectively. Result showed that richness species index in riparian area and diversity index in neighboring area had high correlation with the rangeland conditions. Hence, ecologic management could be used as a tool for evaluation of indices as reflectors of disturbance in rangeland.

Some of arid regions problems of Iran are saline and sodic soils. In improvement and reclamation of Iranian arid rangelands, some foreign species of Atriplex had been imported and adapted for many years ago. The most adapted species was Atriplex canescens. At the present research, some environmental factors, vegetative characteristics (Na, Ca, Mg and K), soil properties (moisture, EC, pH, solute Na and K, hard pan, CaCO3, CaSO4, etc), topography, climate (rainfall, temperature, frost) and management characteristics (pruning, enclosure, grazing, irrigation) were studied on Atriplex canescens in two sites in Hossein Abad-e-Hapeshloo of Shahriyar, Tehran province, Iran. At first, field survey was done and proper sampling method was selected. Based on distance between and within furrows, one hectare reference area was selected for each of low and high freshness sites, respectively. A random-systematic sampling method was used for vegetation and soil characteristics, along three transects with a length of 100 m vertical to furrows, nine plots were established. Along each transect, three profiles were dug and samples were taken from two depths (0-30 cm and >30 cm). The wet and dried soil samples were weighted and soil moisture was estimated. Then, some physical and chemical soil properties were evaluated. Results of soil analysis showed significant diffrences between two sites for pH in lower depth, Ec in the higher depth, CaCO3 and sand in the both depth, silt in the lower depth and clay in the higher depth. The amount of Ec, ESP, CaCO3, clay and Na were increased in lower depth of soil, in contrast, for silt, sand and K, the higher values were obtained in the above layer. For others yraits there was no significant difference between two sites. The mean of vegetation characteristics were more in high freshness site. It was concluded that physical (soil texture) and chemical soil parameters (lime, pH and others) had significant effect on shrub freshness. Moreover, it was likely that management parameters including grazing, irrigation and environmental parameters including topography and water logging had important roles in improper growth of Atriplex shrubs.

Medicinal species of mountain’s kelavs, scientifically named (kelussia odoratissmia Mozaffar.) is an endemic species in Iran. Kelussia odoratissima is a perennial species and belongs to the umbelliferae. From the ancient times, the local and nomad societies had believed that the species traditionally have anti-ache, anti-inflation and anti-cough effects. Seed and root of this species are boiled used to cure the common cold and intense coughs and its organs are been used to treat the stomachache, rheumatism and blood refining. The main purpose of this study was to introduce of K. odoratissima as an endangered medicinal species in Kohgiluyeh region, Iran. Geologic, topographic, climatologic information derived of the maps of them. Soil and plant cover data had been collected using quadrates establishing and analyzed. Result showed that soil texture was sandy clay loam and sandy loam that had %3.25 organic carbon. Annual rainfall was 865 mm that larger portion of it was snow. The Habitat of K.odoratissima was in the range of 2450 to 3000 m of sea level. The region geologically had Asmari, Pabedeh and Gourpi formations. Generally, the habitat of K. odoratissima was in snowy regions of central Zagros with minimum height of 2500 m, mean rainfall was more than 500 mm, with frost period more than 4 months, minimum temperature of -15°C and maximum temperature of 25°C, low depth to half-deep soil with the medium texture and with different slopes.

In order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. Physical and chemical properties of soil are effective in distribution of plant species in local area. To determine the effects of some soil properties on species distribution of Eurotia ceratoides and Stipa barbata in Baghedar summer region of Bafgh, three types of vegetative plants were identified including Artemisia aucheri-Eurotia ceratoides, Artemisia aucheri-Eryngium bungei and Artemisia aucheri -Stipa barbata. Then data of 20 plots were collected for each type in the desert. After drilling 27 soil profiles and providing samples of 0-30 and 30-60 cm from soil depth, pH, EC, CaCO3, organic carbon, CaSO4, and gravel parameters and distribution of soil grain were determined in the laboratory. One-way analysis of variance was made using SPSS software. Analysis of variance showed that clay and CaCO3 in the soil first depth and CaCO3 and Gravel% in the soil second depth have significant differences in three vegetation types. Then to determine parameters affecting on separating vegetation types, principal components analysis was performed on 17 variables (16 soil variables and slope percentage) using PC-ORD software. Results of PCA indicated that in the first axis slope%, clay in the second depth and CaCO3 and sand in the first depth, explain 61% of the variations and for the second axis included sand in the second depth and electrical conductivity and organic matter in the first depth, explain 38% of the variations. The results of the research show that Eurotia ceratoides was more dispersion in areas where the lower and upper layers of soil had less clay and CaCO3 and Stipa barbata is seen in lower layers of soil having more clay and more CaCo3 and less organic carbon and EC in upper soil layers.

The efficiency of three statistical models, AHP surface-weighted density bivariate (semi-quantitative models), stepwise multivariate regression and logistic multivariate regression models were compared in Chehel-Chai watershed in Golestan province, Iran. In current study the hazard map was prepared according to the top model of landslide hazard map. Chehel-Chai watershed is located as one of Gorganrud river sub basins in Golestan province. The distribution map of the area landslide was provided using the stereoscopically interpretation of aerial photos and field observations and nine effective factors including elevation, slope, aspect, lithology, distance from fault, stream and road, land use, and precipitation rate were chosen concerning the expert view and source review. The hazard potential of landslides was also prepared using three models. The differences were compared between models of hazard classes with Chi-square test, the agreement rate of risk maps with kappa index and the evaluation of the model accuracy with total quality index (QS). The risk map was provided based on the risk equation by the combination of the risk maps, the element frequency and the element vulnerability degree. The results showed that all models had 99% reliability level and there were a high separation among the risk classes. Kappa index was variable between 0.0 to 0.2 representing that the correspondence between them is negligible. The weighted (AHP) bivariate statistical model was selected as the best model for the basin with QS equal to 3.62. 12.13% of the surveyed basins were located in high loss class and very high loss class, respectively. It was concluded, 41% of Chehel-Chai watersheds were at moderate risk and from it 13% was in high classes risk that must be considered in risk management, landslide risk and land logistics of this mountainous area.

Livestock grazing is one of the most important kinds of land usage that has a high potential to decrease or increase carbon storage in rangeland ecosystem. This research was investigated the effects of enclosure on soil carbon storage in a rangeland with dominant plants of Artemisia aucheri. Hence, two rangelands of enclosure (Shahtappeh-Chah Mahmood) and no enclosure (Chiro) were chosen in Semnan province, Iran. For soil sampling, 20 plots of 1x1 m2 along with two vertical transects with 100 m length were used in each region. Then, two profiles were dug in 0-15 and 15-30 cm depths in soil of baseline and inter-path of plants in each plot. Data were collected for pH, EC, CaCO3, saturation moisture, soil texture, organic carbon (OC%) and s organic matter (OM%), Soil bulk density and Soil carbon storage and the mean was compared by t-test. The results showed that there was a significant difference (P<0.05) between OC% and OM% of baseline in enclosure and no enclosure rangeland. Soil OC% and OM% in baseline in the first depth was more than the second depth in two study areas. There was a significant difference (P<0.05) between soil OC% and OM% in baseline and inter-path of plants in two depths of enclosure and no enclosure rangelands. Soil bulk density (gr/ha) in baseline and inter-path of plants in 15-30 cm was more than 0-15 cm. In enclosure and no enclosure rangelands, grazing had no significant effects on soil organic carbon storage of baseline in each depth. So, the total carbon in 0-30 cm in each region was 47.46 and 40.85 ton/ha, respectively. There was a significant difference between carbon storage of baseline and inter-path of plants (P<0.05) in two depths in enclosure and control rangelands. It was concluded that higher carbon sequestration occurs in the soil, the soil biological and mechanical activities can increase.