在干旱半干旱沙区，植被塑造地形和影响成土作用的典型例证是灌丛沙堆的形成和发育。固沙植被通过截留大气降水和降尘，影响到固沙区的地形塑造、生物土壤结皮（BSCs）的发育和成土作用。固沙植被在其生长和演替过程中如何塑造地形及影响成土作用？不同类型和配置的固沙植被由于粗糙度的差异如何影响降尘的捕获和风蚀物质的堆积？对这些问题的回答是正确理解干旱半干旱沙区生态格局和过程的基础。本研究将从固沙灌木刚刚建立的初期开始观测灌木对降水和降尘的截留，通过连续监测植物生长、地形地貌变化、BSCs的形成发育及土壤形成过程，结合空间代替时间研究灌丛沙堆的发育及格局，阐明干旱沙区固沙植被对成土过程和地形塑造的影响及其机理。

In arid and semi-arid desert area, topography shaping and pedogenesis functioned by vegetation is charactered by formation and development of Nabkha dunes. Through canopy interception of dustfall and rainfall, sand-fixed shrubs affect topography shaping, biological soil crusts (BSCs) development and pedogenesis. How sand-fixed shrubs shape topography and affect pedogenesis during their growing and succession? and how different types and arrangement of sand-fixed shurbs with various roughness affect dustfall entrachment and deposition of sediments by winds? To answer these questions is a foundation on correctly understanding eclogical pattern and process in arid and semi-arid desert area. The project will monitor the interception of dustfall and rainfall by sand-fixed shrubs from early stage, and also observe continuously plants growth, topographic variation, BSCs development and pedogenesis process, combining with investigation on the development and pattern of nabkha dunes using space-for-time method, to illustrate effects and its mechanisms of sand-fixed shrubs on topography shaping and pedogenesis.