关键词: 额济纳绿洲, 柽柳群落, 沙漠化过程

Abstract: Tamarix community is an important vegetation type distributing on flood land and sandy land in Ejin oasis at the lower reaches of Heihe River. The vegetation and soil were sampled and the two sub-formations of Tamarix community were found at the flood land and sandy land. The characteristics of Tamarix community structure and the soil elements showed that the vegetation is going in the different degraded stages of desertification process. The specie richness and the biomass decreased, the rate of dead branches increased, but no significant change in the coverage, plant high, and plant cluster size. The change of soil element was not much clear with the degradation degree of the sub-formation at flood land, but at the sandy land sub-formation, the salt content of topsoil layer increased, the nutrient, and the organic matter, N and fine particles that less than 0.1 mm significantly decreased. The Tamarix community is the last line to prevent desertification development in the area; we should pay more attention to it and protect the community.

Key words: Ejin oasis, Tamarix community, desertification process