Journal of Rangeland Science
Volume:4 Issue: 3, Summer 2014

Festuca ovina L. is a hyperaccumulating plant which has aroused considerable interest with respect to its possible use for phytoremediation of contaminated soils. This study has been conducted to evaluate the potentials of F. ovina L. to serve as a phytoremediation plant in the cleaning up of Cu in the polluted soils and to identify extraction efficiency of Ethylene Diamine Tetraacetic Acid (EDTA) for desorbing copper in relation to chelator dosage. Seeds have been sown in control and Cu contaminated pots (artificially contaminated with 150 mg kg-1 Cu). Results revealed that Cu negatively affected growth and tolerance indices of F. ovina and the root length was the most sensitive parameter among all measured parameters. The treatments used for assessing EDTA efficiency were 1.5, 3, 6, 15+1.5, 3+3 mmolkg-1, control (C: uncontaminated soil without EDTA) and W (contaminated soil without EDTA). Results showed that the application of 1.5 mmolkg-1 of EDTA did not significantly improve the phytoextraction of Cu and statistically, there was no significant difference in Cu uptake between single and split applications of 1.5 mmolkg-1 of EDTA. A sharp increase in root Cu concentration was observed when 3 mmolkg-1 of EDTA was applied. The highest amount of Cu extracted for the plant tissues was achieved at the doses of 6 mmolkg-1 and 3+3 mmolkg-1 EDTA, respectively. Higher Remediation Factors (RF) were obtained for the plants grown in contaminated soil and the highest RFs (0.08% and 0.07%) were recorded after the addition of 6 and 3+3 mmolkg-1, respectively. Application of EDTA showed a relatively decrease in TI (Tolerance Index) value and the lowest value of TI was recorded in 6 mmolkg-1 EDTA treatment. According to the experiment, EDTA has appeared to be an efficient amendment when Cu phyto-extraction with F. ovina was addressed. But further studies would be needed on investigating the reduction of percolation risk by the amount and process of chelate application.

Species selection based on a new method such as a fuzzy method is one of the most important stages in the successful plantation management planning as choosing a suitable species for the site can be the key to success. This paper is based on a fuzzy extension of the Technique or Order Preference which is similar to Ideal Solution (TOPSIS) method. The purpose of this paper is to develop fuzzy TOPSIS method to improve the quality of decision making for species selection. For this propose, the selection of range species was done using Fuzzy-TOPSIS techniques in 2012 in Sarab Sefid rangeland in Boroujerd, Lorestan Province, Iran. In this method, the ratings of various species versus subjective criteria and weights of all criteria were assessed by linguistic variables represented by fuzzy numbers. Fuzzy numbers try to resolve the ambiguity of concepts that are associated with man judgments. A set of pre-defined linguistic variables parameterized by triangular fuzzy numbers was used by the group to evaluate the weights of various criteria and the ratings of each species. To determine the order of species, the closeness coefficient was defined by calculating the distances to Fuzzy Positive Ideal Solution (FPIS) and Fuzzy Negative Ideal Solution (FNIS). Finally, for the application and verification, an empirical study was performed to demonstrate the model and identify the suitable species. Results show that Fuzzy-TOPSIS method is useful for species selection decision making and the proposed system can provide accurate results. Based on this method, Bromus tomentellus was the best species from frequency viewpoint for the range management.

Study on the livestock diet is one of the main priorities in the management of rangeland in Iran. So, this study was conducted to compare preference values of plant species in three age classes of Kaboudeh sheep (one, three and five year old ones) in rangelands of Bavanat, Fars province, Iran. For each age class, four sheep were selected and their grazing times from different plant species were recorded using a timing method (chronometer) for two hours during the day. The effects of livestock age, plant species and their interactions on preference values of plant species were assessed using a factorial experiment (GLM test). Also, one way ANOVA was applied to compare preference values between plant species for each age class of animals. The results showed that the age of the animals and plant species had significant effects on preference values of plant species. Species of Poa pratensis and Avena fatua for young animals and Acer cinerascens for older animals had higher preference values. In addition, species of Poa pratensis and Prangos ferulaceae had appropriate preference values for all three age classes of animals. As vegetation cover in the study area is mostly consisted of the bushes and shrubs in autumn and on the other hand, sheep has little ability to graze this kind of plant species subsequently during the grazing period, they dominantly focus on herbal species. In general, animal diet demands cannot be provided from rangelands and it is required to use the methods of manual feeding with dry forage and supplements. One of the possible alternatives is to harvest and store the annual yield of P. ferulaceae in spring in order to feed the animals in autumn and winter.

In arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. A study was done to analyze the effects of grazing on plant species diversity and Plant Functional Types‘ (PFTs) diversity of arid and semi-arid rangelands. We analyzed plant richness and diversity data from 75 sampling plots located in five bioclimatic zones of Khabr National Park containing a total of 73 plant species. Ward's hierarchical clustering was then used to cluster all plant species into eight PFTs according to the chosen traits. For each site, grazing intensity was estimated in three classes (low grazing, medium and high grazing intensities). We found that as grazing intensity increased, total species richness and diversity were decreased. Considering PFTs as total showed the same pattern for species; however, each PFT diversity and richness didn‘t display a significant different response to grazing. Looking at each PFT relative cover change in different grazing intensities showed that PFT1 and PFT8 were grazing sensitivities while PFT6 and PFT7 benefited from grazing and their relative cover increased consistently in response to the increased grazing intensity. PFT3 and PFT4 had the highest relative cover rates in moderately grazed areas. PFT2 and PFT5 had a complicated response to grazing and their relative cover was the minimum at moderately grazed sits. This finding may imply that grazing has completely negative impacts on the community structure and it seems that it reduces plant species and functional types‘ diversity and richness. It can be also concluded that the analyses on PFTs level possibly give more insight into the grazing response of plant community in arid and semi-arid rangelands than those on species level but there is a need for further studies.

Salinity stress is one of the most important abiotic stress factors limiting the plant's growth. Seed priming is known as a method which improves the germination performance in seeds in stress conditions. The objective of this study was to compare the effectiveness of Hydropriming and Halopriming on germination performance of Secale montanum while growing under the NaCl-salinity stress. Hydropriming and Halopriming were used in the study to prime seeds. For the Halopriming treatments, concentrations of 0, 125, 250 and 500 mM of sodium chloride were prepared. This experiment was carried out in four levels of salinity stress. A significant tow-way interaction (priming × stress) was found for all characteristics. Germination percent in Halopriming showed a significant decrease with the increases in duration and concentration of treatments. Higher root and shoot length values of S. mountanum were observed in Hydropriming treatment but as compared to the control, it was not statistically significant. S. montanum appears to be moderately salt-tolerant. The results of this study indicated that Halopriming had a negative effect on the germination and growth of S. montanum. The disadvantage may be due to the varied plant species, imbibing time and seed moisture. On the other hand, these effects are probably due to an excessive increase and accumulation of Na+ and Cl− ions to the seed tissue. From the present study, it can be concluded that seeds of S. montanum are sensitive to priming technique and priming of this species needs to use the other priming methods.

The objectives of this research were to study the varieties and relationships of yield and quality traits under two harvesting management procedures concerning forage dry matter (DM yield) and 5 quality traits such as Dry Matter Digestibility (DMD%), Water Soluble Carbohydrates (WSC%), Crude Protein (CP%), Acid Detergent Fibre (ADF%) and total ash in tall wheatgrass (Agropyron elongatum). In this study, 17 genotypes were examined in two separate experiments for conservation (1 cut per year) and frequent cutting management procedures (2 cuts per year) in a dry land farming system over three years (2006-2009) in Damavand rangelands, Iran. Results suggested that two cut management procedures resulted in lower yield with high quality. The means of annual DM yield were 1482 and 3053 kg ha-1 for two and one cutting management procedures. Considering the conservation management, the CP and DMD were decreased in the opposite direction to DM yield, WSC and ADF. The local population of 774M (Takestan) with the means of 1740 and 3837 Kg ha-1 for DM yield had a higher production for 2 and 1 cut management procedures, respectively. DM yield was positively correlated with total ash in frequent cutting. DMD was negatively correlated with ADF in both management procedures and positively correlated with CP in frequent cutting. Results of Principle Component Analysis (PCA) showed that the first three components were accounted for 78 and 82% of the total variety for the conservation and frequent cutting, respectively. In both management procedures, DMD and ADF in the PC1 were identified as the important traits. Using Ward cluster method, 17 genotypes were grouped into 3 clusters. For the conservation management, the genotypes in cluster 3 and for frequent cutting, genotypes in cluster 2 coupled with the quality traits had higher productivity.

Interrupting the processes which control ecosystem resources has dramatic impacts on the rangeland conditions. To protect ecosystems and landscape, it needs to understand the ecosystem processes which regulate the ecosystem resources. As main components of ecosystems, patches and inter-patches play important roles in energy and materials cascade. Ecologically, functional parameters such as stability, infiltration and nutrient cycling serve as key factors determining the movement of sediments, nutrients and organic matter as well. The present research aims to evaluate and compare the ecological patches of grasses, shrubs and mixed grasses- shrub using indices of stability, infiltration and nutrient cycling. Therefore, sampling was carried out in Qahavand rangelands located in the south east of Hamadan province, Iran on three patches of grass (Cynodon dactylon), shrub (Camphorosma monspeliaca L. and Astragalus microcephalus) and mixed grasses-shrub (Camphorosma monspeliaca + Cynodon dactylon) to evaluate the aforementioned parameters. Samples were taken along three 50 m transects using LFA (Landscape Function Analysis) method. Three indices of stability, infiltration and nutrient cycling and their individual contributions on the whole ecosystem's functions were determined. Results showed that all three patches vary significantly in function so that the mixed patch (Camphorosma monspeliaca + Cynodon dactylon) may be accounted for the highest values among the others. The study area had a good level of stability and nutrient cycling while infiltration rate was moderate mainly due to much proportion of clay in soil texture. Somehow, results of soil profile study in the area imply good stability and moderate infiltration.

In many studies, topographic factors have been considered as an important factor in establishing the vegetation in different ecosystems. So, it affects vegetation composition and diversity by influencing soil moisture, fertility and soil depth. The aim of this research was to investigate the effects of slope, elevation and geographical aspects on species growth, forage production and vegetation cover in Yazi rangeland, Noor province, Iran. Sampling was done along three transects with the length of 150 m in each unit. Along each transect, 15 plots (1 m2) were established with 10 m distances. In each plot, species name, growth form, cover percent and soil surface percent such as percentages of stones, pebbles and amount of litter were recorded. Also, the rangeland production was measured by the clip-and-weigh method. Data were analyzed and mean comparisons were done using Duncan method. Results showed that the geographical aspects had significant impacts on forage production, vegetative form and species composition. Northern aspects had the highest forage production rate and species frequency. Also, elevation had a significant effect on forage production and vegetative form so that the elevation of 1600-1900 m and 2200-2500 m had the highest and lowest effects. Also, according to forage production and vegetative form in the range of slope classes, it is specified that it has also a significant effect on forage production seen in higher slopes.