Journal of Rangeland Science
Volume:4 Issue: 2, Spring 2014

Environmental pollution with heavy metals is a global disaster that is related to human activities. This study was conducted to determine the extent of heavy metals accumulation by plant species in Lia industrial city (Qazvin, Iran) and to investigate the remediative capacity of native plant species grown in the contaminated soils. Soil and industrial wastewater sampling was done radially along transects with 300 m intervals from exit point of wastewater at three sites. In each sampling point, along 100 m transects within 5×2 m plots, the plant samples and soil samples were collected in depth of 0-20 cm and 20-40 cm from rhizosphere zone. Concentration of copper, zinc and chromium in root and shoot of 11 plant species, soil and wastewater were analyzed in three sits for mentioned metals. Bio Concentration factors and translocation factor were determined to ensure phytoremediation availability. Results showed that the concentrations of metals in the soil and wastewater greatly exceeded the threshold limit values. The contents of metals in soils ranged in the order of Cr>Zn>Cu and in wastewater were in the order of Zn>Cr>Cu, respectively. Results showed that Scirpus maritimus L. and Phragmites australis (Cav.) Trin. ex Steudel presented the highest accumulation of Zn, Cu and Cr in their root tissues which were suitable for phytostabilization (with a high BCF couple with low TF). The lowest extractable Zn (7.24 and 3.29 mgkg-1 for shoot and root respectively, BCF=0.07) and extractable Cu (2.56 and 2.80 mgkg-1 for shoot and root respectively, BCF=0.14) were related to Hordeum glaucum L. Moreover, the relatively lowest values of Cr were measured for Taraxacum officinale L. Results indicated that the species, which had low metal bioaccumulation in their roots and high TF, could play important roles for removal of heavy metals through phytoextraction.

The range conditions explain its health as a management tool. Obviously, the implementation of this important assessment requires the most appropriate study method for each region. In order to select the most appropriate methods of range conditions in Kabirkooh grasslands of Zagros in Iran, five estimation methods (i.e. six-factor, four-factor, vegetation and soil combination, value of pasture and climax) were studied in three key and critical areas. In each area, five stations were selected using the randomized-systematic method. The differences between methods were analyzed using the factorial experiment by the help of the randomized complete blocks design with five replications. The results showed that there were significant differences (p<0.01) between both range conditions’ determination methods and different areas. Regarding Kabirkooh rangelands in current circumstances, four-factor method for semi-arid region is more applicable for the range condition determination. Biomass production and range conditions had a close relationship using Pearson correlation test (p<0.01, r=0.86).

Nowadays, in many rangelands, due to over grazing, and problems that some plants have in germination, the rate of forage production is greatly reduced. So to take advantages of the benefits of such plants, it is necessary to identify and remove barriers of germination and establishment of suitable plants. The present study was designed to investigate different treatments of breaking dormancy and stimulating seed germination of Astragalus adscendens and Astragalus podolobus and offer the most effective treatment to enhance germination and growth rate. The experiment was conducted using Completely Randomized Design (CRD) with four replications. Treatments included hot water for 5 minute, 30% hydrogen peroxide for 5 minute, 98% sulfuric acid for 5 minute and chilling at 4°C for 10 days. Data were collected for seed germination percentage, Germination Rate (GR) and Mean Germination Time (MGT). Based on the results, treatment with 98% sulfuric acid for 5 min for A. adscendens and hot water for 5 min for A. podolobus were the best treatments to break dormancy and stimulate seed germination, so that the germination percentage increased from 44% to 82% in A. adscendens and from 28% to 62% in A. podolobus. In A. adscendens 98% sulfuric acid reduced the amount of MGT from 8 days for control treatment to 5 days. In A. podolobus hot water treatment was more effective on MGT reduction and reduced it from 7 to 5 days. Although sulfuric acid had the highest effect in breaking dormancy, but its application in a vast scale is not easy, therefore the hot water was suggested as the substitution treatment.

To determine the potential habitat of two rangeland species of Salsola rigida and Agropyron trichophorum in Qasr-e-Shirin, Iran, Geographic Information Systems (GIS) and Remote Sensing (RS) techniques were used. At first, several maps (vegetation cover and land uses maps and thematic maps of various organizations) were collected or prepared. For digitizing geology, vegetation and conventional states maps, topographic data layers, soil maps and soil data layers the softwares of ARC/ INFO, ILWIS and TOSCA were used. Land use map of Qasr-e Shirin city was prepared using IRS1 satellite imagery. The current habitats of studied species were determined by visiting the area and limiting it by GPS and marking on map. Three sites for each of species were selected. 10 soil profiles were randomly drilled in depth of 35 cm within each site. The soil parameters such as EC, Texture, pH and organic matter for each sample were measured. The results showed that from the total rangeland area (6270 ha), two locations 1677.3 ha (26%) were fitted for growth of Salsola rigida of which 211 ha (3.36%) from this area belongs to original habitats and 1466 ha remained, was belong to the potential habitat. For the second species, the results indicated that two areas totally 1356 ha were habitat of Agropyron trichophorum which 167 ha (2.66%) were belonged to the current original habitats and the rest of 1189.8 ha (18.97%) was belonged to the potential habitat for Agropyron trichophorum.

Rangeland ploughing and cultivation using dry land farming crops may be a major reason for the destruction of natural resources in the semiarid and sub-humid regions which may significantly change the composition and reduce the stability of the affected communities. In present research, an abandoned ploughed site was compared with a nearby reference site in the semiarid rangelands of Baharkish, Quchan, Iran in spring and summer of 2010. Frequency and canopy cover of all plant species were recorded within 40 quadrates of 1m2 area. Simpson, Shannon-Weiner, Hill and Macintosh indices for biodiversity, Margalof and Menhening for richness and Camargo, Simpson, Modified Nee, Smith and Wilson for evenness were used. Floristic composition, plant life forms, and important value of major plant species were compared with respect to the sites. Land ploughing and subsequent abandonment had increased total number of plant species (richness) but decreased the species heterogeneity (evenness). It resulted to non significant differences in species diversity between the ploughed and reference sites. Ploughing had increased (8%) the important values of respruting plant species. Therefore, patchy distribution of clonal plants had reduced species evenness within the abandoned site. Furthermore, there were some increases in number of therophytes (100%) but hemicryptophytes (24%), chamaephyte (33%) and phanerophyte (100%) species were reduced in the abandoned site. In conclusion, lower evenness and high proportion of annual plants should make the abandoned site more fragile and sensitive against the future environmental fluctuations.

Knowledge on habitat characteristics and nature of regional vegetation in rangelands is a prerequisite for any planning and proper range management along with sustainable development of renewable natural resources. Rangelands in southern and western highlands of Kashan, Iran are of good vegetation diversity but unfortunately, palatable and desirable species are endangered in recent years. This research aims to investigate habitat characteristics and phenology of five range species including Prangos latiloba, Prangos uloptera, Ferula ovina, Astragalus eriopodus and Onobrychis melanotricha. Several field studies were conducted and the distribution of each species in highlands of Kashan was determined using topographic maps, land capability, and GPS. Ten key species were selected in each region to study their phenological stages including vegetative growth, flowering, seed maturity, and seed dormancy. In spring, summer and autumn, 15-day visits and a 30-day visit in winter were performed. Finally, the distribution of each species and phenological stages were presented in maps and graphs. Our results showed that the dormancy period in most species started from early August and continued until late March. As temperatures rise in late March, vegetative growth starts and continues until mid-May. Flowering stage was in a period of mid-May and the end of June; afterwards, seeding stage and seed dispersal have started.

This research aims to evaluate the effects of seed scarification on five perennial Astragalus species including A. effusus, A. vegetus, A. subsecundus, A. brevidens and A. cyclophyllon in the field conditions. Seeds were sown after scarification with sandpaper by hand in the field of Homand Absard Rangeland Research Station, Damavand, Iran in autumn in 2008. The seeds were sown using split plot design based on the completely randomized block design with three replications. In each plot, seeds of each accession were sown on two parallel lines (scarified and control) with 2 m length and 75 cm along with the distance of 50 cm for each accession. Vegetation indices including forage production, canopy coverarea, plant height, number of flowering stems and seed yield were studied over three years. Data were analyzed using split plot for specific years in sub plots and mean comparisons were done by Duncan method. Results indicated significant differences between treatments, species and years for all the traits. Interactions between species and year were significant for all the traits except plant height. Seed scarification caused an increase in forage production, canopy cover area and number of flowering stems. According to the results, mechanical seed scarification has been recommended to be done before planting herbaceous Astragalus. The species A. vegetus (accession Kurdistan) and A. effusus (accession Urmia) were recommended for range revegetaion and rehabilitation in semi dry lands with the annual precipitation more than 300 mm.

Rangelands are known as one of the main income resources for their exploiters. In the recent century, management of Iran rangeland has undergone vast transformations because of vulnerable socio-economic conditions of pastoralists. A study was done to provide a clear picture of the status and utilization of Aq Qala rangelands via assessing internal and external environmental factors affecting the utilization of rangelands. Thus a SWOT was adopted to identify and assess the positive and negative factors in internal and external environments. Data were collected through free and brainstorming interviews with an emphasis on the knowledge and experience of rangelands’ exploiters. After content analyzing of primary collected data, Analytic Hierarchy Process (AHP) and spectral questionnaires were respectively used for range management technicians and exploiters to quantify gathered qualitative information. Based on the results, priority of the main factors of SWOT related to the rangelands utilization was respectively identified for opportunities, threats, weaknesses, and strengths. The results revealed that chance of income extension from livestock productions (weight= 0.102) had the first priority in the opportunities section. In the threats section, drought and its consequences in rangeland exploitations (0.095) had the highest threats from pastoralists and technicians views. Lack of water resources and their uneven distribution (0.028) and the importance of rangelands and their exploitation in the livelihood and economy (0.022) were respectively the main factors in the strengths and weaknesses sections.