人工输水来恢复已干涸50多年的青土湖,对阻隔腾格里沙漠和巴丹吉林沙漠联合具有重要的生态意义。经过人工输水后3年的定位观测,分析青土湖的人工水域区群落组成、结构变化和环境关系,得出以下结论:植物群落空间分布依水源呈现草甸-盐化草甸-荒漠三个梯度层,近水区为白刺群丛和芦苇群丛,向外是戟叶鹅绒藤群丛,再向外是沙蒿和一年生植物群丛。植物群落结构表现为密度增加和不同空间区的植物生活型变化。在距水面0-50m的地下芽植物芦苇数量激增,而距水面250-300 m之间,则是地面芽和一年生植物所占比例较大。青土湖输水引起植物群落演替不仅决定于原生群落类型,而且受地下水位和土壤盐分的空间变化影响,在短期内形成依水的空间隐域植被梯度,是植物适应环境变化配置的多向演替。植物群落的时间演替序列为荒漠→草甸,而空间演替序列为荒漠→盐化草甸→草甸。
Importing water artificially to restore the Qintu Lake which has dried up 50 years has important ecological significance to stop the merger of Tengger Desert and Badain Jaran Desert. Having observed for three years after importing water, analyzing the community composition, structure change and environmental relations of importing waters area in Qingtu Lake, we found that according to water sources, the spatial distribution of plant communities appeared three gradient layer of meadow-saline meadow – desert. Form. Nitraria tangutorum and Form. Phragmites communis were near the water area, Form.Cynanchum sibiricum was little outward, and then were Artemisia sphaerocephala and annuals associations. The plant community structure showed density increase and changes of plant life-form in different spatial regions. The number of underground bud of Phragmites communis increased sharply in 0-50 m from the margin of the water, and in 250-300 m from the margin of the water it was a larger proportion of ground buds and annual plants. Qingtu lakeshore vegetation succession not only determined the native community type, but also was affected by water table and soil salinity after importing water. And it formed intrazonal vegetation gradient along the water in the short term. It was multi-succession of plant adapting to environmental configurable change. Time succession of plant community was desert plant → meadow, and the space succession series was desert pant → salt meadow → meadow.