Pubescent wheatgrass (Agropyron trichophorum (Link) Richt.) is growing in semiarid regions of Iran at altitude of 500 to 2000 m. Among different grasses growing in Iran, A. trichophorum is relatively resistant to grazing and defoliation as compared to other species of Agropyron genus which are dominant in the most summer rangelands. In Emam Gholi protected summer rangelands, Ghochan, Khorasan province, Iran, A. trichophorum as a dominant grass was selected for our study, and was subjected to a series of defoliation treatments. Forty eight quadrates of 0.5 m2 were established in two macro-plots and subjected to one, two, three, and four weekly interval clipping started in May 6, 2016 in vegetative stage and other treatments of once clipping started in May 6, May 19, June 3, and a control treatment was clipped only once in July 15. Floral stalks of A. trichophorum were counted before clipping. Then, quadrates were clipped to the ground surface, air dried and weighed for different treatments. Using ANOVA, the responses to frequent clipping showed that there were no significant differences in daily, current, primary, and total production of A. trichophorum (p>0.05) which may be due to the reservation of carbohydrate in roots and base of this grass after 15 years of protection. Low slope of sigmoid curve for weight of clipped plants also confirmed the resistibility of this species to defoliation, but as the frequency of clippings were increased, the number of floral stalks was decreased showing an exponential model (p<0.0). To find the allowable use of A. trichophorum, further years of research will be required to evaluate the responses to defoliation in different locations. پرونده مقاله

Severe range degradation was critically extended in many region of Iran and caused many rangelands were restricted and interwoven with croplands in a complex system. Therefore, rangeland planning and inventory as an isolated activity has become almost impossible. Current landscape planning involves contributions of different social organizations often with different interests and with different desired outcomes. In this study, landscape is considered as a management unit. I have proposed an integrated model based on traditional pastoralism which will facilitate sustainable land use of natural resources in future. Combining the benefits of different rural groups is the most important part of our decision making plan which provides solution to the problems of non- dependency of villagers to the rangelands. Formation of research work group from urban specialists and rural skilled workers with cooperation of international organization are the keys of preparation the integrated projects. Our monitoring of the past land use, suggests that the use of rangelands by local herders was being co-adapted with natural environments. We have proposed an integrated model that includes various levels of management, needs of social organizations, potential rangeland classes, and agro-ecological-based dry land farming. The main advantage of planning based on landscape unit is that by consideration of ecological aspects of past use and present features of land use, integrated models can be provided based on land suitability. Combining the benefits of different rural groups is the most important part of such decision making which provides solution to the problems of non- dependency of villagers to the rangeland as Badripour et. al. (2016) emphasized on them. پرونده مقاله

One of the most important issues in rangeland management is the estimation of carrying capacity. To estimate range production, we need to use a large number of sample plots to clip plants in a sampling scheme; therefore, due to vast area of rangelandsand time and cost limitations, direct estimation of rangeland production by sampling plots is almost impossible. Since there is a strong relationship between climatic factors and rangeland production, using indirect estimation methods of rangeland production is important. The relationship between production samples and climatic factors can be easily predicted. Present study was conducted in five locations of Spandol, Zarchak, Torogh, Aselme, and Dash, Iran in 2013. In this research, the relationships between forage production and three climate parameters including precipitation, temperature, and precipitation to temperature ratio (P/T) were investigated. For each parameter, 33 variables (periods) were considered. Stepwise regression analysis was used to select the most effective periods of precipitation and temperature. The relationship between production and March to April precipitation and November to December temperature was positive but with October to March temperature, it was negative. The relationship between production and P/T was negative in May to June and positive in January to March. In general, simultaneous of rainfall and temperature had effective roles in increasing dry matter production of grasslands in the studied areas. پرونده مقاله

To find an accurate and rapid method of estimating herbage crop, Double Sampling (DS), Comparative Yield (CY), and clipping and weighing (CW) methods were applied to a summer rangeland in North-eastern Alborz Mountains, Iran. The method was called SMFY (Simulation Model of Forage Yield) to emphasize the statistical aspects of simulated model. In representative stands five 1-m2 reference plots were chosen to represent the ranges of standing crop. Using a systematic-random design, 180 1-m2 plots were ranked against the reference plots for CY, visually estimated for DS, and subsequently, all of them were Clipped and Weighed (CW). After clipping and weighing 5 reference plots with 6 replications for CY and estimating and clipping 37 plots for DS, regression lines were plotted between the estimated, ranked, and clipped plots. This study was conducted during 2011-13. There was high correlation (0.90-0.99) for DS and CY, so the estimated and ranked data were corrected based on the regression equations. There were strong linear relationships between the corrected and clipped data for the DS and CY methodswhich confirmed the suitability of both methods against the CW, so all of 180 estimated plots were corrected and were compared by ANOVA. The non-significant F for CY, DS, and CW confirmed the high efficiency of DS and CY, so based on the estimated production, grazing capacity of study area was calculated. Preferring one of these methods depends on further research in time and cost efficiency of DS and CY. Available DM of 389.75 kg/ha support 6.5 AUM per ha and for the grazing period of 4 months, each hectare of this rangeland can carry on 1.62 AU per ha. The current stocking rate of study area is about 0.82 AU per hectare which was suitable based on carrying capacity of study area. پرونده مقاله

Colocynth (Citrullus colocynthis) is one of the major medicinal plants, naturally growing in deserts of Middle East and North Africa. Extending cultivation of this species is useful for sand dune fixation and livelihood of the local inhabitants. In spite of numerous studies on seed germination, there are still debates on the best methods of breaking seed dormancy for colocynth. Moreover, seed morphology, phonological stages and habitat conditions of this species is almost unravelled. This study was conducted in 2016-2020 at Gonabad desert, Iran. We established five line transects of 200 m and five plots of 4×4 m, and vegetation parameters, phenology and root morphology, soil charactristics of colocynth were measured. The pH varied between 7.0-7.5 in bare soil and 8.0-8.1 under the canopy of colocynth habitat. The soil of study area was classified as slightly saline. Two weeks pre-chilling at 4°C and night -day temperature range from 25-40°C significantly increased seed germination. In our study area, colocynth was detected as a perennial forb with long and ligneous roots (more than120 cm). Its vegetative growth starts in middle of May, seed ripening and shedding occur in October and November. Average fruit volume was 2.62 cm3 and seed number counted in each fruit varied between 250 to 420 by the length of 4-7 and 2-4 mm width. Big size fruits contained the highest seed numbers. The best harvesting time in terms of both economic value and seed viability is ripening of fruits. پرونده مقاله