Effect of Temperature on Phenology in Triple-Awned Grass (\u3ci\u3eStipagrostis plumosa\u3c/i\u3e)

Phenology of triple-awned grass in different stages of vegetative growth, flowering and seed falling was investigated. Each phenological stage was related to minimum and maximum air and soil surface temperatures. Soil surface temperature was measured two times per day during different seasons. Climate data were obtained from the nearest weather station. The study was carried out in sand dunes of band-e-rig of Kashan in the central region of Iran. This species is important in terms of wind erosion control and livestock feeding in arid areas. The results showed that air temperatures ranged from –22 oC to 41.5 oC and soil temperature varied from –3 oC to 52 oC during the growth stages

Variation in the Quality of Forage of Six Rangeland Species in Different Phenological Stages

An understanding of forage quality is fundamental to the measurement of grazing capacity. In addition, knowledge of forage quality is necessary for planning grazing and developing range improvement and development programmes, such as planting and seeding of rangelands. Among the different factors that affect forage quality, phenological stage is particularly important (Cook, 1972; Caballero et al.,2001). The objective of this study was to investigate the effects of plant species, phenological stages and life form on forage quality indices

Scenario analysis for integrated water resources management under future land use change in the Urmia Lake region, Iran

Arid and semi-arid regions are particularly vulnerable to global environmental change because of their fragile climatic conditions. The rapid development of land use is expected to affect aquatic ecosystems in these regions. In this study, we focused on how land use change affects the stream flow and inflow to Urmia Lake in the Mordagh Chay basin, Iran. This case-study exemplifies dynamics found across a much larger region. We mapped changes in land use between 1993–2015 using satellite imagery and modeled future changes using the Dyna-CLUE model. We projected future land use change until 2030 under four scenarios: continuing of the current trend of water use, 40% water withdrawal reduction, and two other scenarios with 40% water withdrawal reduction and improvements of irrigation efficiency up to 50% and 85%. Between 1993–2015, 21% of the study area changed to orchard and arable land mostly at the cost of rangeland. However, upon reduction of water withdrawal our analyses showed that garden must decrease between 27% and 40%. Rainfed cropland is projected to experience a major increase in all scenarios, especially in the case of reduced water withdrawal, where it will increase by 217%. In order to achieve sustainable water resources management land use plays a major role and leads to different land use futures in this type of semi-arid regions

Impacts of future climate and land use change on water yield in a semi‐arid basin in Iran

Studying the interaction between hydrology, land use and climate change is necessary to support sustainable water resources management. It is unknown how land management interventions in dry climate conditions can benefit water yield in the context of climate and land use change interactions. In this study, we assessed the effects of both land use and climate change on the Mordagh Chay basin water yield using the Integrated Valuation Ecosystem Service and Tradeoffs model (InVEST). First, we modelled the current water yield, followed by developing six combined climate‐land use scenarios until 2030 based on the CCSM4 climate model for the RCP4.5 and RCP8.5 scenarios. We used three future land use scenarios simulated by the Dyna‐CLUE model. The trend scenario of land use change, which does not include any improvements in irrigation efficiency, significantly affected basin water yield under both climate scenarios. Water yield decreases by 19.8% and 31.8% for the RCP4.5 and RCP8.5, respectively. Under all land use scenarios that included improvements in irrigation efficiency the water yield responded positively. For the RCP4.5 scenario, the water yield was projected to increase between 16.6 and 18% depending on the land use scenario. The increase in water yield under the RCP8.5 climate scenario was much lower than for the RCP4.5 scenario (about one third). Overall, the results showed that by adopting appropriate irrigation efficiency, it is possible to achieve a better balance between environmental needs, regional economic and agricultural development. The results provide insight into possible sustainable development options and also provide guidance for managing the other Urmia Lake sub‐basins while the approach of integrated assessment of climate, land use change and land management options is also applicable in other conditions to help inform sustainable management

Vegetation community in relation to the soil characteristics of Rineh rangeland, Iran

The aim of this study was to investigate relationships between soil properties and plant species to determine the most effective factors separating vegetation communities in Rineh rangeland. Three stratifying variables were selected including slop, aspect and elevation. The study area was partitioned by combining these classes to generate homogenous units. 1m2 quadrates were located at sampling sites in each homogenous unit randomly. Vegetation cover data were recorded using ordinal scale of Daubenmire cover-abundance scores in each quadrate. Soil samples were collected based on area from 0-15, 15-30 cm depths in each sampling site. Total nitrogen, organic matter, pH, total phosphorus, water retention capacity, permanent wilting point, available water capacity, potassium, water holding capacity, CaCO3, saturation moisture, bulk density, real unit weight and percentage of fine earth fragments (sand, silt and clay) were measured. Both classification and ordination techniques were employed including TWINSPAN classification, DCA and CCA. The TWINSPAN classification of the sample sites have resulted in ten groups. According to the results of DCA, length of gradient represented by axis 1 was >5 SD, indicating that CCA was the appropriate ordination method. CCA axis 1 was correlated to phosphorus (-0.460) in the first layer and phosphorus (-0.493), sand (0.533) in the second layer while the CCA axis 2 was correlated to phosphorus (0.394), sand (0.533) in the second layer. The species-environment correlations are higher for the first three canonical axes, explaining 18% of the cumulative variances

GPS AND REMOTE SENSING APPLICATION FOR RANGELANDS MONITORING

Abstract-In range management planning access to accurate and up-dated information is important. Furthermore, separation of changes trend and its causes can be obtained by a monitoring program. Application of advanced technologies such as Remote Sensing and Global Positioning System and other usable instruments for range management purposes is essential in a range monitoring program. In this research, from range monitoring point of view, capacity of GPS in according obtained data from ground samples with related satellite information was studied. Before verifying feasibility of GPS usage in according digital and ground data, proper time, correct method of usage and also GPS models were tested. In two provinces of Tehran and Markazi, six reference points were selected and in each point, eight GPS models including Etrex Vista, Silva, Meridian Platinum, Tracker, Magellan 2000 XL, Magellan 3000 XL, Magellan MLR and Promark X were tested. The results showed that the best time of GPS application in regions was in the morning. Among, GPS type, Etrex Vista had less error than other models. Also, differential method was appointed as better method for geographic coordinate's estimation. After selection of suitable method for coordinates measurement, coordinates of quadrats along four transects in six sampling sites were determined. The results showed that GPS receivers could be used to accord accurately ground data with satellite data

Plant Richness and Diversity Response to Different Treatments of Animal in Kalashak Rangelands (Case Study: Kermanshah Province)

Evaluation of plant richness and diversity is important in rangeland ecosystems because biological control, conservation of genetic resources and the control of natural ecosystems are possible by identifying diversity. One of the factors affecting the richness and diversity is animals' utilization of the vegetation. Therefore, this research was done to study the plant richness and diversity response to different treatments of animals. To this end, four sites with none, half, equal and twice as much grazing capacity were selected. Treatments were identified due to vegetation cover changes, distance from water, distance from the village and grazing times. Using located transects, samples were (systematic randomization) taken from vegetation (transects four and plots 40 and in the area a total of 160 plots were harvested). The results showed that the highest species richness and diversity belonged to sites' grazing capacity equal and grazing capacity half. But this was the least in the without-grazing site. Thus, animals' exploiting the rangelands properly (grazing capacity equal and grazing capacity half) can increase the richness and diversity. Lack of rangeland long-term grazing leads to poor plants. So, both severe grazing and long-term exclusion should be avoided. The full protection of rangeland does not necessarily lead to the maximum diversity

Accumulation and distribution of metals in Phragmites australis (common reed) and Scirpus maritimus (alkali bulrush) in contaminated soils of Lia industrial area

The concentration of three metals, zinc, copper and chromium in roots, rhizomes, stems and leaves of Phragmites australis (common reed) and Scirpus maritimus, and in the corresponding sediment and water samples from Lia industrial area (Qazvin, Iran) were investigated to determine difference in distribution among plant organs. Data were collected at during 1-year period. Results showed that metals concentrations in plant organs decreased in the order of roots ¿ rhizomes ¿ leaves ¿stems. Concentration of Zn, Cu and Cr were enriched in roots and rhizomes of both plants in summer and autumn. Stem concentrations of metals in S. maritimus however, had no significant difference throughout 1-year period. In contrast, the metal contents of leaves were elevated in spring and autumn. Patterns of leaves and stem concentration of Zn, Cu and Cr were similar to S. maritimus leaves.This research was supported by a grant from the Natural Resources Faculty of Tehran University.Peer Reviewe