desert

摘要： In domestic animals,the body weight is the ultimate result of growth which forms the basis of meat production.Sex,nutrition,breed and health are the main factors which influence the growth rate in animals.Heredity which is the major factor affecting the prenatal growth either directly through the genotype of the fetus or indirectly through the genotype of the dam.The prenatal growth patterns and development of the camel fetus is just like the fetus of cattle,however,the meat output from the breeding she-camels is limited often due to longer gestation periods,longer milk feeding periods,lower calving rates under traditional management system.A lot of variation regarding camelid daily growth rate exists that varies widely between breeds,within breeds and regions.There is a significant effect of pre-weaning and post-weaning growth rates on the final body weights in camelids.Management system,the available milk quantity,husbandry practices and vegetative conditions are the main factors that affect the pre and post weaning growth rates of camel calves.However,it is partially dependent on the availability of browsing species throughout the whole year.In this specific study,an effort has been drawn to look into the literature data for camel growth assessment.

摘要： Here where the Yellow River runs through the undulating dunes of the desert,the distinct achievements of anti-desertification efforts are the pride of all Chinese people.

摘要： Dunhuang,an oasis of culture surrounded by the vast sands of the Gobi Desert,served as a refuge for ancient weary Silk Road travelers 1,000 years ago.Carved into the cliffs high above the Dachuan River,the Mogao Caves southeast of this city in Gansu Province comprise the largest,most richly endowed,and longest used treasure house of Buddhist art in the world,inspiring young artists to this very day.Inside the grottoes,murals painted with mineral pigments have stood the test of time and still shine brightly and brilliantly.To carry forward this painting technique,Lian Yang(pseudonym),an artist in her 30s known widely by this name,started from scratch,determined to make the traditional art increasingly known among younger generations.

摘要： Deserts,the sea of death,are the places where life ends.However,they will become a different scene if there is electricity in the deserts:vegetation will regenerate,crops will grow in rows,the sky will be blue and full of birds,and flowers will be fragrant.This is the scene of the Ulan Buh Desert in Dengkou County,Inner Mongolia,China.The local government's achievements and experience in sand control can be summarized into four items:(1)Photovoltaic power generation,saving coal resources;(2)Developing deserts:expanding land resources;(3)Finding uses for water flowing through deserts and below them;(4)Improve the environment and eliminate the poverty of the people in the sand area.

摘要： The Mogao Caves are remote in Dunhuang City,Gansu Province.Located in the Gobi Desert,they are most famous for their exquisite frescoes(壁画).Dunhuang,as its exotic(奇异的)name suggests,represents a fascinating dream of the romance of the ancient Silk Road.

摘要： Investigating the relationships between vegetation dynamic and edaphic factors provide management insights into factors affecting the growth and establishment of plant species and vegetation communities in saline areas.The aim of this study was to assess the spatial variability of various vegetation communities in relation to edaphic factors in the Great Salt Desert,central Iran.Fifteen vegetation communities were identified using the physiognomy-floristic method.Coverage and density of vegetation communities were determined using the transect plot method.Forty soil samples were collected from major horizons of fifteen profiles in vegetation communities,and analyzed in terms of following soil physical and chemical characteristics:soil texture,soluble Na+concentration,sodium adsorption ratio(SAR),electrical conductivity(EC),pH,organic matter content,soluble Mg2+and Ca2+concentrations,carbonate and gypsum contents,and spontaneously-and mechanically-dispersible clay contents.Redundancy analysis was used to investigate the relationships between vegetation dynamic and edaphic factors.The generalized linear method(GLM)was used to find the plant species response curves against edaphic factors.Results showed that plant species responded differently to edaphic factors,in which soluble sodium concentration,EC,SAR,gypsum content and soil texture were identified as the most discriminative edaphic factors.The studied plant species were also found to have different ecological requirements and tolerance to edaphic factors,in which Tamarix aphylla and Halocnemum strobilaceum were identified as the most salt-resistant species in the region.Furthermore,the presence of Artemisia sieberi was highly related to soil sand and gypsum contents.The results implied that exploring the plant species response curves against edaphic factors can assist managers to lay out more appropriate restoration plans in similar arid areas.

摘要： Megha Nath,male,Nepalese,born in 1975,currently head of Crew 8647B line-placing team of Saudi Department of BGP.Megha Nath has been recognized as Four-Star Employee for four times,and Five-star Employee for one time.In 2012 when Saudi S71 project was commenced,Megha Nath joined Crew 8647B and became a member of BGP.

摘要： Water availability,which enables plant growth and animal activity,regulates dryland ecosystem function.In hyper-arid ecosystems,rain cannot support vascular plant growth.Therefore,hyper-arid vegetation is restricted to the lower topography,where runoff accumulates.Typically,food resources originating from areas of dense vegetation are dispersed across the desert floor,enabling animal life in areas lacking vascular plant growth.However,certain regions,such as the hyper-arid upper topography,may be devoid of plant-derived food resources.The present study examined arthropod activity in the upper topography of a hyper-arid desert,in comparison with arthropod activity in the lower topography.Pitfall traps were utilized to compare arthropod activity along unvegetated ridges with activity in parallel,vegetated riverbeds.Surprisingly,the study revealed dense arthropod communities in the barren upper topography.Arthropods collected in the upper topography represented 26%of total arthropod abundance.In addition,the overlap between arthropod identity in the ridges and wadis(i.e.,riverbeds)was low,and certain arthropods were strongly affiliated with the ridges.The upper topographic communities included high numbers of silverfish(Zygentoma:Lepismatidae),malachite beetles(Psiloderes),and predatory mites(Acari:Anystidae),and these arthropods were present at various life stages.It remains unclear how arthropod communities can persist in the unvegetated upper topography of the hyper-arid study area.These results raise the possibility that other food sources,independent from vascular plants,may play a significant role in the life history of hyper-arid arthropods.

摘要： Objective The Badain Jaran Desert,located in western Inner Mongolia,is the second largest desert in China(Fig.1 a).It is well known for the coexistence of lakes and megadunes in the southeastern part of the desert(Fig.1 b).

摘要： Barchan dunes are among the most common accumulative phenomena made by wind erosion,which are usually formed in regions where the prevailing wind direction is almost constant throughout the year and there is not enough sand to completely cover the land surface.Barchans are among the most common windy landscapes in Pashoueyeh Erg in the west of Lut Desert,Iran.This study aims to elaborate on morphological properties of barchans in this region using mathematical and statistical models.The results of these methods are very important in investigating barchan shapes and identifying their behavior.Barchan shapes were mathematically modeled by simulating them in the coordinate system through nonlinear parabolic equations,so that two separate equations were calculated for barchan windward and slip-face parabolas.The type and intensity of relationships between barchan morphology and mathematical parameters were determined by the statistical modeling.The results indicated that the existing relationships followed the power correlation with the maximum coefficient of determination and minimum error of estimate.Combining the above two methods is a powerful basis for stimulating barchans in virtual and laboratory environments.The most important result of this study is to convert the mathematical and statistical models of barchan morphology to each other.Focal length is one of the most important parameters of barchan parabolas,suggesting different states of barchans in comparison with each other.As the barchan's focal length decreases,its opening becomes narrower,and the divergence of the barchan's horns reduces.Barchans with longer focal length have greater width,dimensions,and volume.In general,identifying and estimating the morphometric and planar parameters of barchans is effective in how they move,how much they move,and how they behave in the environment.These cases play an important role in the management of desert areas.