河水漫溢对荒漠河岸林植物群落生态特征的影响

从河水漫溢干扰对塔里木河下游植物群落物种多样性的影响以及对天然植被恢复作用上开展了分析和研究，结果表明：（1）输水前塔里木河下游仅见9科13属17种植物，但输水后漫溢区出现了12科26属34种植物，其中的18种植物是非漫溢区未曾发现的；（2）从样地植被调查计算的多样性指数看，漫溢区物种的多样性和丰富度比非漫溢区有明显增加；（3）从漫溢后一定时间内植物群落中不同物种的重要值看，漫溢后1年生草本植物迅速萌发，而多年生草本由于根系和繁殖上的优势逐渐在群落中占据优势；（4）由于胡杨、柽柳等植物在多次漫溢条件下易于萌发，因此多次漫溢后这些乔、灌木植物逐渐占据群落中的优势地位；（5）在漫溢过程中由于微地形改变了漫溢干扰的强度因此漫溢后微地形差异造成地表生态特征出现明显的差异；（6）通过讨论，漫溢干扰对塔里木河下游这样一个严重受损生态系统恢复的作用十分明显，但是这一作用的体现是与输水后下游生态水文过程完整性的恢复相联系的。

The influence of the river flooding disturbance on the native vegetation restoration in the lower reaches of Tarim River

This paper analyzes the influence of the river flooding disturbance on biodiversity of the degraded ecosystem and discusses the function of the disturbance on the vegetative restoration in the lower reaches of Tarim River.The results show:(1)there are seventeen species,thirteen genera and nine families before river flooding in the lower reaches of Tarim River while thirty-four species,twenty-six genera and twelve families after river flooding,in which appear eighteen new species;(2)from the plants diversity indices in investigated samples,the species diversity and riches indices in river flooding areas increase more obviously than those in non-flooding areas;(3)from the importance value of the different species after one time of river flooding,the annual herb grow quickly while the perennial herb with deeper root or root clone becomes a dominance in plant community;(4)after several times of river flooding,some arbors and shrubs such as Populus euphratica and Tamarix ramosissima Ledeb are prone to germinate and become a ecologic dominance in plant community;(5)during the period of river flooding,the ecological characteristics of the overground vegetation have differences due to the different intensity of the river flooding disturbances caused by microtopographty;(6)the discussed results indicate that the river flooding disturbance has an obviously favorable influence on restoring the degraded ecosystem in the lower reaches of Tarim River.The influence is connected with the integrality of restoring the ecohydrological process.