关键词: 沙生植物, 抗旱机制, 植被演替, 科尔沁沙地

Abstract: The different ways and different mechanisms in physiology of several desert plants resisting to adverse environment were investigated under air dehydrate, high temperature conditions. Agriophllum squarrosum, Convolvulus chinensis grown on shifting sand dune were typical kinds of avoiding drought due to death caused by water lost in their leaves rapidly, and very strongly lipid peroxidation resulting in cell membrane injury under two stresses was the reason; Artemisia halondendron grown on semi shifting sand dune was of higher ability to resist drought depending on its osmoregulation; Pennisetum centrasiaticum and Setaria viridis grown on fixed sand dune are true drought resistant plants relying on changes in physiological metabolism resulting in very quickly response action of protective enzyme to bad condition, and on accumulation in proline, protein, soluble contents. The results showed that the ability of resistance to stress condition in the desert plants played a very important role in rank of vegetation succession of Horqin sandland on development from the shifting to the fixed dune, in which the evolution law was: ① development from avoiding drought to resisting drought; ② development from resisting wind sand to tolerating drought; ③ development in the way of survive from mono way to multi way; ④ development from resistance to high temperature, wind sand and drought to only tolerance to drought.

Key words: Desert plant, Mechanism of drought resistance, Vegetation evolution, Horqin sandland