干旱区生态环境知识资源中心

Natural accumulation of wind-borne sediments within or around the canopies of plants plays an important role in the ecological and evolutionary dynamics of many coastal and desert ecosystems. The formation of such phytogenic mounds (nebkhas) creates patches that can strongly influence the spatial distribution of plant and soil resources. Nabkhas are common, and are dunes formed around plants. Individual plants must reach 10 - 15 cm in height before they can effectively trap sand. The largest nabkhas accumulate around trees, and can reach 10 meters in height. Nabkhas can be composed of sand, silt, or pelletized clay, the grains of which can be cemented by organic materials. Once trapped in a nabkha, these cemented particles do not readily become wind re-entrained. This paper examine some aspects of the development, morphological and ecological characteristics of nabkhas formed around perennial dominant plant. Nabkha area develop mainly under the control of Aeolian process. The study focused on eleven dominant plant species covered desert of Kuwait. Each plant have special character. Cyperus, Haloxylon and Rhanterium lied in highly degraded area. Haloxylon speciesis more efficient in trapping sand compared to other desert plants. Astragalus sp have highest carbonate percentage of all nabkha. Citrullus sp have lowest hight of nabkha. Sabkha plant such as Nitraria, Tamarix, Halocnemum and Salicornia have low pH and carbonates and high in moisture content and electrical conductivity. Lycium sp is characterized to have the longest distances between branches and plants in comparison to other plant specie.