JOURNAL OF RANGELAND SCIENCE
Year:2017 | Volume:7 | Issue:2|Papers Count:9

Extensive flood damages all over the world necessitate its control and operation. Hydrologic impacts of land use change appear in many ways such as total runoff, and flood peak flow. This study was performed in 2014 and aimed to investigate the impacts of land use changes on the occurrence of floods in the catchment of Boostan dam in Golestan province, Iran. For this purpose, Watershed Modeling System (WMS) was used to compare land use areas in 1996 with those in 2006 using the corresponding maps. After the calibration and validation of model in each period, rangeland and forest degradation and its effect on the flooding of catchment were evaluated using two representative parameters of peak flow and volume of flood. Land use maps of both time periods were compared and the achieved results revealed that the total area of rangeland was increased whereas good rangeland areas were decreased, fair rangelands were increased and poor rangeland areas were remained relatively constant that mean a decrease in high quality rangelands in the catchment. Also, the forest areas that decreased intensified flood. But peak flow and flood volume of the whole catchment have been mitigated. In spite of negligible change in total Curve Number (CN) of the catchment, rangelands in downstream and near residential areas converted to the agricultural lands and upstream agricultural lands converted to high and medium density rangeland. This means that distribution of land use changes was in such a way that influential upstream watersheds in flooding were associated with the reduced CNs. So, the implemented biological measures have reduced the flooding potential of the catchment. Sensitivity analysis of the model showed that 5% decrease in CN can cause 40% decrease in peak flow of the catchment and in contrast, 5% increase in CN can enhance flood peak flow up to 60%.

Biodiversity plays a crucial role in stability and productivity of natural ecosystem. The main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. Therefore, fifty different Land Unit Tracts (LUT) were identified in Khod-Neuk basin, Yazd province, Iran, in 2010. Vegetation and soil samples were taken in the LUT’s representative stands.Two way indicator species analysis (TWINSPAN) method were used to identify ecological groups on the basis of presence-absence and canopy cover of plant species. The diversity indices including species richness, Shannon-Wiener evenness index, Simpsons’ dominance index, Shannon-Wiener diversity index and Simpsons’ diversity index were analyzed in vascular plants based on species canopy cover data. Then the relationship between land unit distribution and diversity indices was assessed using Canonical Correspondence Analysis (CCA). Results showed that ecological groups were quite different in terms of species composition and plant diversity indices. So that, ecological group 2 had the lowest dominance index and the highest scores of other indices and ecological groups 1 and 5 had the lowest richness and along with ecological group 3 had the lowest species evenness values. Ecological group 5 had the lowest and the highest scores of Shannon-Weiner diversity index and Simpsons’ dominance index respectively. The second group located in the mid altitudes with high saturation percentage and low Na, lime and Sodium Adsorption Ratio (SAR) had the highest diversity indices. Therefore, these groups are enough to delineate rangeland into ecological units which could be used for management purposes.

Smirnovia iranica(Sabeti) synonym: Smirnovia turkestana (Bunge) is a deciduous perennial bushy species of the Fabaceae (Papilionaceae) family. The species grow on sand dunes of desert areas, having a deep vertical root and very long horizontal or lateral roots. They have an important role in natural vegetation of desert and sand dune stabilization. Limited growing areas, grazing due to good palatability, and foliage quality of the plant have put this species under threat. Seed preservation under cryogenic conditions at -196ºC is an important approach to conserve seeds for a long period. In this study, seeds of theS. iranica were collected from natural habitats of the plants and three pre-cryopreservation treatments including PVS2, Desiccation, and 30%Glycerol were applied before transferring the seeds into liquid nitrogen (LN) at -196ºC for 1 week, 1 month, and 1 year (in 2015). Subsequently, the seeds were removed from the liquid nitrogen, imposed to heat shock and evaluated under laboratory, greenhouse and natural habitat conditions. The cryopreserved seeds of various cryopreservation periods germinated normally under laboratory and greenhouse conditions. In laboratory conditions, there were no significant differences between periods of seed storage in cryogenic conditions for seed germination trait. The highest seed germination percent (84%) was observed in the desiccation pre-cryopreservation treatment. In pre-cryopreservation treatments as well as cryogenic storage periods under greenhouse conditions, seed germination and seedling establishment were significantly different. In natural habitat, the cryopreserved seeds germinate and grow to normal seedlings and plants. The results showed thatS. iranica seeds can be successfully stored in cryogenic conditions for a long period.

Fire is one of the incorporate vegetation management practices for grasslands and semi-arid rangelands. It may affect symbiotic relationship between range plants and mycorrhiza. Accordingly, this research was aimed to investigate the effects of a spring prescribed fire on the symbiotic relationships between mycorrhiza and 6 plant species. The study was conducted in a semi-arid steppe rangeland called Dehbar, Torghabeh in Mashhad, Iran. A prescribed fire was applied on 20th April 2015. Soil and plant samples were taken one month later. Colonisation and spore density were measured on the root of 6 different species. Spring fires significantly increased fungi spores in the rhizosphere of all plant species with the highest and lowest frequencies (42 and 24 per gram dry soil) obtained forPimpinella tragium and Artemisia aucheri, respectively. Fire effects on colonization varied from high to no effect ranges. The increases in the mycorrhiza propagules after a prescribed burning during the growth season might be due to a suddenincrease of nutrients from plant ashes. Although the studied plant species were different in terms of morphology (canopy and root type), phenology and life form (geophyte, perennial grasses and shrubs), the spring fire increased the colonization rate for plant species that had just started vegetative plant growth (Stipa barbata, Artemisia aucheri and Pimpinella tragium) but it had no effects regarding the plant species (Poa bulbosa, Agropyron trichophorumand Astragalus gossypinus) that were fully grown at the time of burning and/or had terminated seasonal growth period at the time of soil sampling. Therefore, in terms of plant-mycorrhizal symbiosis, a prescribed spring fire might increase the competitive advantage of perennial late season species as compared to annual early season species which are mostly ephemeral or invasive plants.

Drought is a major problematic phenomenon mostly for semi-arid areas of Iran.During drought periods, reduction in vegetation levels causes such problems as soil erosion, surface runoff, flood risk, etc. Therefore, the assessment of drought effects on plant covers is the most important issue. This research was conducted in 2015 using the extracted vegetation indices from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor data during 2000-2008. In Esfahan province, monthly rainfall data from 25 stations were used to derive the Standardized Precipitation Index (SPI) at 3 month scale, March to September. SPI was used to validate three index results in drought estimation.The result of calculating SPI showed that droughts occurred in 2000, 2001 and 2008. The result of Pearson correlations between SPI and Vegetation Indices showed that the highest correlation was related to VCI index and the lowest correlation was related to TCI index.The result of NDVI index in 2000, 2001 and 2008 indicated that the poor vegetation cover was increasingly occurred. Based on the results of this study, it can be concluded that the NDVI and VCI indices concerning MODIS sensor can be a good alternative for estimating the drought with respect to meteorological indices and consequently can give a better idea on drought conditions in the study area. It was shown that remote sensing data can be practically useful in analyzing the drought events in Esfahan province.

There are many remediating methods for the polluted soils but only phytoremediation is a cost effective, environmental friendly, aesthetically pleasing approach that is most suitable for many countries. The purpose of this study was to investigate the potential of native plants for phytoremediation of contaminated soils with lead, zinc, cadmium and nickel in the rangelands around National Lead & Zinc Factory, Zanjan, Iran. Sampling was done at 11 sites on May, 2014 and plant samples were collected from 14 native plant species. Three soil samples were taken at each site. Soil samples were taken from the rooting zone. Extraction of Pb, Zn, Cd and Ni from plants was done by acid digestion. Plant samples were digested in the di-acid mixture (3: 1) of nitric acid (HNO3) and perchloric acid (HClO) and soil samples were digested with 4M HNO3 acid. Metals of Pb, Zn, Cd and Ni were extracted from plant and soil samples were determined using Inductively Coupled plasma Optical Emission Spectroscopy “ICP-OES”.In general, the results showed that no hyperaccumulators of Pb and Zn were identified in the area. All plants were classified as low lead accumulators, excluder and moderate accumulators, low zinc accumulators or excluders; though Pb and Zn concentrations in the plants were higher than standard range. Standard range of lead and zinc in rangeland plants is 0.2-20 and 1-400 mgkg-1, respectively whereas the species of Brassica juncea and Scariola orientalis were classified as Cd hyperaccumulators and Scariola orientalis and Echium amoenumwere classified as Ni hyperaccumulators. The normal value of Cd and Ni in these plants were 0.1-2.4 and 0.02-5.0 mgkg-1, respectively. Thus, these native plants had an implication of carrying out phytoremediation in the rangeland soils around National Iranian Lead & Zinc Factory, Zanjan.

Allelopathy is one of the main factors limiting the plants growth. The present study investigated the effect of aqueous extract of leaves and fruit ofArtemisia sieberi that is an important species for rangeland rehabilitation on seed germination and seedling growth of three alfalfa species (Medicago sativa cv. Nikshahri, Medicago polymorpha and Medicago scutellatacv. Robinson) in laboratory and glasshouse. Treatments were five concentrations of 0, 25, 50, 75 100%Artemisia extract. Treatments were evaluated using a completely randomized factorial experiment in four replications in germinator and pots separately (2014). Data were collected and analyzed for the germination percent, germination rate, seedling length, seedling weight and seed vigor index. Means comparisons were made using Duncan test. The results showed significant differences between extract concentrations ofArtemisia on all of traits in both growth conditions (P<0.05). There was a decrease trend for all of the traits. Germination percent ofM.polymorphawas stopped in low concentration of Artemisia extracts (25%) whereas there were linear decreasing trends for the other specie until irrigation by 100% extraction.M.sativahad a higher germination rate and M. scutellata had higher vigor index values in all the treatments. Results of the study indicated thatArtemisia had strong allelopathic effects and prevents from the germination and seedling growth of alfalfa.

The effect of environmental factors on plant vegetation is different. Therefore, it is necessary to evaluate role of these factors in medicinal plants growth, development and essential oil. This study was performed to investigate the effect of factors on qualitative and quantitative variations of the essential oil ofVerbascum songaricum in its habitats in central Zagros Mountains, Iran in 2012.V. songaricum aerial biomass was collected in flowering stages from four rangeland sites in Isfahan (Dareh Hose, Ghahiz, Ghaleghadam, Semirom) and one site in Kohgiluyeh, and Buyerahmad (Dena) provinces, Iran. The samples were dried in open air and their essential oils were extracted through digestion method. Gas Chromatography Mass Spectroscopy (GC-MS) was used to identify essential oil composition as Alcohol, Hydrocarbon, Amin, Acid, Ester and Ketone of species in five sites. The most important environmental factors such as climate, and physiographic, soil physical and chemical properties were determined. In order to investigate the relationship between environmental factors and plant essential oil, Ordination analysis was performed using Redundancy Analysis (RDA). The results of correlation analysis indicated that the most important environmental factors affecting the essential oil were annual rainfall (r=0.86), frozen days (r=0.86), Aridity index (r=0.86), Altitude (r=0.86), gravel (r=0.74), nitrogen (r=0.78), organic matter (r=0.62) and soil texture (r=0.68). Results showed that there was an increase in essential oil production inV.songaricumunder semi-arid cold climate, uplands, higher precipitation, relatively light texture and fertile soil. According to RDA analysis, two habitats were identified. The first habitat was more appropriate for essential oil production ofV. songaricum (Dareh Hose, Semirom and Dena) in comparison with the second one (Ghahiz and Ghaleghadam). As a result, the first habitat was considered as a suitable natural place for the cultivation and domestication ofV. songaricum.

Introduction: The challenges related to the preservation of Mongolia’s pastureland, its quality and condition are key concerns for the livestock sector. However, scientists, researchers and government agencies tend to focus solely on rangeland ecology and livestock. All too often, herders are overlooked and omitted from the discourse. This is the main reason I want to talk about people of the Mongolian grassland and Social justice issues in rangelands.....