关键词: 民勤, 绿洲-荒漠过渡带, 景观格局, 景观动态, 森林生态系统, 碳水关系, 水分利用效率, 模型, 全球变化

Abstract: By using ERDAS and GIS techniques, a systematic analysis was made on the landscape pattern and its dynamics in typical oasis-desert transitional zone of Minqin Region in 1960-2005. Forest land and cultivated land were the dominant factors leading to the landscape change. During the research period, oasis expanded toward the periphery by 2-3 km, and the transitional zone moved toward desert, with its width increased from 4 km in 1960 to about 9 km in 1987 and decreased rapidly then. In 1978-1987, the landscape change reached the historically highest level; but after 1998, the landscape pattern became relatively stable. In the whole transitional zone, the period with higher fragmented index occurred in 1978-1987, during which, the quickest variation among patch types was observed. The fragmentized regions were located in the area 2 km from oasis and in the forestation area. In 1960-1987, arbor forest tended to vanish. Shrubbery area increased widely before 1987, and decreased sharply since then. The intensity of land reclamation kept increasing in 1960-1998 but decreased after 1998, while the abandon rate had a trend of linear increase during the research period.

Key words: Minqin, oasis-desert transitional zone, landscape pattern, landscape dynamics, forest ecosystem, carbon and water interactions, water use efficiency, model, global change.