塔克拉玛干沙漠是我国最大的沙漠，气候极端干旱，风沙活动频繁，沙漠边缘广泛分布着以柽柳灌丛为主的灌丛沙堆，是灌丛沙堆类型与分布、形态特征、形成演化及其对气候变化的响应等多角度研究的理想场所。本研究利用遥感影像解译、表层沉积物样品采集、样品理化性质测试相结合的方法，较系统地分析了塔克拉玛干沙漠边缘灌丛沙堆空间分布规律及表层沉积物特性，讨论了风沙环境对灌丛沙堆空间分布、沙堆表层沉积物粒度和养分空间差异的影响，得到以下结论：

（1）塔克拉玛干沙漠灌丛沙堆空间分布特征表现为沙漠南部灌丛沙堆数量高于北部，西南部高于东部。不同区域所发育的灌丛沙堆大小也存在较大差异，随灌丛沙堆直径的增大，分布区域与分布密度逐渐缩小。直径（d）小于5 m的小型灌丛沙堆广泛分布于沙漠南部山前冲积扇、荒漠-绿洲过渡带以及北部塔里木河冲积平原；中型灌丛沙堆（5 m < d ≤ 10 m）在北部塔里木河冲积平原与东部铁干里克过渡带大面积分布，在沙漠南部、西部零星状分布；大型灌丛沙堆（10 m < d ≤ 20 m）主要分布在策勒、皮山荒漠-绿洲过渡带边缘、轮台县以南的塔里木河冲积平原以及东部铁干里克周边；特大型灌丛沙堆（d > 20 m）分布极少，一般分布在大型灌丛沙堆周围。

（2）塔克拉玛干沙漠灌丛沙堆表层沉积物的优势粒级为极细沙、细沙和粉沙。灌丛沙堆表层沉积物的粒径介于2.03Φ~5.37Φ之间，平均粒径为3.39Φ，东、西部灌丛沙堆表层沉积物的平均粒径略小于南部和北部；分选系数介于0.55Φ~1.84Φ之间，分选性从较好至较差均有分布。

（3）塔克拉玛干沙漠灌丛沙堆表层土壤养分存在一定的空间差异。沙漠北部、南部灌丛沙堆有机质和全N含量略高于东部和西部；全P和全K含量没有明显的空间变化规律。塔克拉玛干沙漠灌丛沙堆表层土壤质地与土壤养分之间关系密切，随着黏土和粉沙含量的增加，土壤中全N和有机质含量逐渐增加，全K含量逐渐减少。全P含量也与黏土和粉沙含量正相关，但相关性较弱。

（4）强烈的风沙活动，为大型灌丛沙堆的发育提供了充足的动力条件与物质基础。沙源相对不足而风力较强（如塔克拉玛干沙漠东北部东北风作为优势主风向的区域）、或沙源充足而风力很弱（如塔克拉玛干西南部）、或沙源不足且风力较弱（如塔克拉玛干南部山麓冲洪积扇），都不利于大型灌丛沙堆的形成。

（5）风沙活动对塔克拉玛干沙漠灌丛沙堆表层沉积物粒度与养分特征的控制作用较弱，植被等环境因素可能占据主导地位。在大尺度风况条件控制下，塔克拉玛干沙漠灌丛沙堆表层沉积物表现出自沙漠东、西部向中部粒径变粗的趋势，但养分特征与输沙势的关系不明确。

As the largest desert in China, the Taklimakan Desert is an ideal place to study from multiple perspectives, such as the types and distribution, morphological characteristics, formation and evolution of the nabkhas and the response to climate change, which is characterized by extremely arid climate and frequent sandstorms. On the edge of the desert, Tamarix Cones are widely distributed. By combining the methods of remote sensing image interpretation, sample collection of surface sediments and testing of physical and chemical properties of samples, this study not only systematically analyzed the spatial distribution of nebkhas and the characteristics of surface sediments in the Taklimakan Desert, but also discussed the influence of wind-sand environment on the spatial distribution pattern of nabkhas, as well as the grain size and nutrient characteristics of the surface sediments. The main conclusions are as follows:

(1) The spatial distribution of nebkhas in the Taklimakan Desert is characterized by a higher number of nebkhas in the south of the desert than in the north, and a higher number of nebkhas in the southwest than in the east. There are some differences in the size of nebkhas developed in different regions. With the increase of the diameter of nebkhas, the corresponding distribution area and distribution density are gradually reduced. Small nebkhas which is less than 5 m in diameter are widely distributed in the piedmont alluvial fan in the south of the desert, the oasis-desert ecotone and the Tarim River alluvial plain in the north; Medium-sized nebkhas (5 m < d ≤ 10 m) are distributed in large areas in the Tarim River alluvial plain in the north and the oasis-desert ecotone in the east, and sporadically in the south and west of the desert at the same time; Large nebkhas (10 m < d ≤ 20 m) are mainly distributed at the edge of the oasis-desert ecotone in Cele, Pishan, the Tarim River alluvial plain south of Luntai County, and the vicinity of Tieganlik in the east; In addition, the largest nebkhas (d > 20 m) are rarely distributed, which are generally distributed around large nebkhas.

(2) In the Taklimakan Desert, the dominant grain sizes of surface sediments of nebkhas are very fine sand, fine sand and silty sand. The sand grain size ranged from 0.55Φ to 1.84Φ and the mean grain size is 3.39Φ. Compared with the grain size parameter of surface sediments from nebkhas in the north and south of the desert, the grain size is finer in the east and west. The sorting coefficient ranged from 0.55Φ to 1.84Φ, indicating that the sorting ability ranged from better to poorer.

(3) The characteristics of soil nutrients from nebkhas have spatial differences in the Taklimakan Desert. In the north and south of the desert, organic matter and total nitrogen contents were slightly higher than those in the eastern and western deserts. As for total phosphorus and total potassium contents, there was no obvious spatial variation. Soil texture and soil nutrients of nebkhas are closely related in the Taklimakan Desert. That is, as the content of clay and silt increased, total N and organic matter contents in the surface sediments of nebkhas gradually increased, and total K contents gradually decreased. Total P content was also positively correlated with the content of clay and silt, but the correlation was weak.

(4) Strong wind-blown sand activity provides sufficient dynamic conditions and material basis for the formation and development of large-scale nebkhas. Under these conditions, it is not conducive to the formation of large-scale nebkhas. The first situation is the sand source is insufficient relatively and the wind-blown sand activity is strong, such as the area in the northeast of the Taklimakan Desert where the northeast wind is the dominant wind direction. The second situation is the sand source is sufficient and the wind-blown sand activity is very weak, such as the area in the southwestern of the Taklimakan Desert. The other situation is that the sand source is insufficient and the wind-blown sand activity is also weak, such as the piedmont alluvial fan in the south .  

(5) The impact of wind-blown sand activity on the grain size and nutrient characteristics of the surface sediments from nebkhas in the Taklimakan Desert is relatively weak, which is mainly due to the dominant environmental factors such as vegetation. Under the control of large-scale wind conditions, the surface sediments of nebkhas show a trend of coarser grain size from the east and west to the middle of the desert. However, the relationship between nutrient characteristics and the sand drift potential is not closely related.