关键词: 民勤, 绿洲边缘, 柽柳, 时空变化, 驱动因素

Abstract: Tamarix is not only a salt-resisting and drought-tolerating tree, but also a excellent wind-breaking and sand-fixing plant, which has ever played significant role in rehabilitating and improving the desert ecological environment of Minqin county. Tamarix ramosissima Ledeb forestry is the main Tamarix forestry at edge of Minqin oasis, which has occurred degradation along with the environment getting drought in recent 40 years. In Tamarix ramosissima Ledeb forestry, the number of xerophytes and super-xerophytes increased, the width of forestry decreased and the coverage of Tamarix ramosissima Ledeb and its community all reduced. At present, even the Tamarix ramosissima Ledeb forestry in Dam area, Spring area and Lake area all took place certain degradation. Especially, the remained width of Tamarix ramosissima Ledeb forestry in Dam area are 30~75 meters, and the forestry only live on the seeping water from farmland. As for the driving factors for spatial-temporal variation of Tamarix ramosissima Ledeb forestry, we found out that surface water vanishing is the inducing factor, groundwater table lowering and soil moisture reducing are the dominant factors.

Key words: Minqin, at edge of oasis, Tamarix, spatial and temporal variation, driving factor