Morphological Characteristics of Carelinia caspica Nebkhas in the Oasis-desert Ecotone in Cele,Xinjiang,China

Based on observed data of carelinia caspica and carelinia caspica nebkhas and statistical methods,we analyzed morphological characteristic carelinia caspica nebkhas and the relation between the nebkhas and the plant morphology,and estimated the quality of sand fixed by plants at the oasis-desert ecotone of Cele,Xinjiang of China.The results are as follows.(1) Carelinia caspica Nebkhas can be mainly categorized into shield-shaped nebkhas at early developing stages and hemispherical nebkhas at stable developing stages according to different development periods.There is a linear correlation between length and width of shield-shaped nebkhas,and so do the basal area and height,but there is a quadric linear correlation for hemispherical nebkhas.During the development process from shield-shaped nebkhas to hemispherical nebkhas,the length of the nebkhas decreases,but the height,width and volume of nebkhas increases as plants grows.(2) There is a significant correlation between the development of nebkhas and the form of plants.The length of shield-shaped nebkhas is twice as long as that of plants,and the volume of shield-shaped nebkhas is 1.5 times as large as that of plants.The length and volume of hemispherical nebkhas are 0.5 times as large as those of plants.(3) It is estimated that the volume of Carelinia caspica nebkhas can be 50 000 m3 per km2 at the oasis-desert ecotone,which indicates that Carelinia caspica nebkhas fix a great deal of sand surrounding the oasis and plays an important role in oasis protection.