Evaluation and Determination of the Appropriate Method for Assessing Optimum Utilisation Rate of \u3cem\u3eEurotia Ceratoides\u3c/em\u3e in Upland Grasslands of Iran

Determination of optimum utilisation rate for different range species is an important factor in assessing range grazing capacity. The vast rangelands in Iran with diverse vegetation types require an accurate, economic and quick method to determine the optimum utilisation rate for different range species. This experiment was conducted to determine the most appropriate method to determine the optimum utilisation rate for Eurotia ceratoides, which is one of the important grass species in upland grasslands in Iran

Multivariate and an ordination approach to classify the attractiveness of the plant species in pastoral lands

To identify the foraging plants by honeybees and determine apicultural potential, a sample collection of species was carried out with the commencement of rangeland plants at 6 different stations in the Freidan summer rangelands during 2010. Attractive index (AI) of each plant was determined by direct observations based on the average number of bees visiting and the length of time that each bee spents on the flowers. By using ordinate method, the AI data were classified into four main groups. The most import vegetation families utilized by the bees in the area were Compositae Labiatae, Umbeliferae, Cruciferae, Gramineae, Liliaceae and Caryophyllaceae. The results of the assessment carried out on the plant diversity showed that between 88 plant species, 70 species were utilized by the bees. These species were unpalatable for grazing animals and were dominant in degraded rangelands. The Class I group comprised of Papaver dubium, Onobrychys sativa, Astragalus gossipianus, Thymus kotschyanus, Eryngium billardieri, Echinops cephalotes and Alhagi camelorum. The Class II group comprised of Eremurus persicus, Peganum harmala, Astragalus sp., Centaurea sp., Scariola orientalis, Medicago lupulina, Ferula gummosa and Mentah longifolia. The Classes III and IV comprised of the species, Euphorbia, Tragopagon caricifolius, Centaurea, Salvia sp, Acantholimon erinaceum, Convolvulus arvensis, Achillea falcate and Cynodon dactylon. The results indicated that the more extensive uses of the pollen of these plants by the honeybees were associated with the higher attractiveness of the flowers and the presence of more nutritive materials in the pollen and nectar

Using remote sensing data for vegetation cover assessment in semi-arid rangeland of center province of Iran

To determine suitable indices for vegetation cover and production assessment based on remote sensing data, simultaneous digital data with field data belonged to summer rangeland of southern part of Isfahan province were analyzed. During 2 years of monitoring, annuals, grasses, forbs and shrubs vegetation cover and total production data from sixty 1 square meter plots in each site were collected. The Global Positioning System (GPS) was used to measure coordinates of plots and transects. Geometric correction and histogram equalization were applied in image processing and image digital numbers were converted to reflectance numbers. In the next stage, all vegetation indices were calculated from ASTER (Advanced Spaceborn Thermal Emission and Reflection Radiometer) image data and compared with vegetation cover estimates at monitoring points made during field assessments. A linear regression model was used for selecting suitable vegetation indices. The results showed that there are significant relationships between satellite data and vegetative characteristics. Among indices, NDVI vegetation index, using high infrared and low red ASTER bands, consistently showed significant relationships with vegetation cover. Estimation of vegetation cover with NDVI vegetation index was more accurate predicted within rangeland systems. Using produced model from NDVI index vegetation crown cover percentage maps were produced in four classes percentage for each image. Generally introduced indices, provided accurate quantitative estimation of the parameters. Therefore, it is possible to estimate cover and production as important factors for range monitoring using ASTER data. Remote sensing data and Geographic Information System are most effective tools in natural resource management

Sediment yield assessment at basin scale using geospatial technique

Soil erosion and sediment yield from catchments are key limitations to achieving sustainable land use and maintaining water quality in nature. One of the important aspects in protecting the watershed is evaluation of sediment produced by statistical methods. Controlling sediment loading in protecting the watershed requires knowledge of soil erosion and sedimentation. Sediment yield is usually not available as a direct measurement but is estimated using geospatial models. One of the geospatial models for estimating sediment yield at the basin scale is sediment delivery ratio (SDR). The present study investigates the spatial SDR model in determining the sediment yield rate considering climate and physical factors of basin in geographic information system environment. This new approach was developed and tested on the Amammeh catchments in Iran. The validation of the model was evaluated using the Nash Sutcliffe efficiency coefficient. The developed model is not only conceptually easy and well suited to the local data needs but also requires less parameter, which offers less uncertainty in its application while meeting the intended purpose. The model is developed based on local data. The results predict strong variations in SDR from 0 in to 70 % in the uplands of the Basin