摘要
通过塔里木河下游生态输水后植物群落及其环境因子的系统取样调查,采用β多样性指数,从时空维上分析了生境差异与物种的恢复速率差异。结果表明:物种多样性差异与环境水分条件有着密切的关系,在地下水埋深小于5 m时,物种恢复速率的发生率达100%,而在地下水埋深大于5 m时;多样性恢复的率达46%。生境异质性较高的群落,水分条件较好,其物种恢复速率相对较高,表现为河边低地、地表未起沙生境与人工灌溉生境具有较高的物种恢复速率。生态恢复过程中,人类的干预对局部生境中物种多样性恢复产生了一定的影响,但物种替代速率与恢复速率的大小最终决定于水分条件的可利用性与环境劣变程度。
Lying in the Desert from the west to southern Xinjiang Province, Tarim River runs through the northern edge of the Taklimakan the east, and the main stream from the Xiaojake to Taitema Nor, with the length of 1 321 km. However, the degradation of riparian vegetation at the lower reaches in the last 50 years has been due to im- poundments and diversions of surface water and the removal of groundwater for human use at the upper stream of the river basin. Since 2000, the eco-water had been transported to the dry riverway for restoring the riparian vegetation and controlling desertification. The restorable rates of species diversity and species turnover rates during the five years of water transporting are the main concern of this paper. The β diversity on spatial and temporal dimension, calculated with the Cody index, were used as species turnover rates and restorable rates of plant communities in the study area. The results showed as follows： the species restorable rates of herbaceous plants had influence on diversity of plant communities ; the species turnover rates and restorable rates were related with water conditions of environment ; when the mean annual depths of groundwater ranged between 0 and 5 m, the incident rate of restoration of species diversity reached at 100%, and while the mean annual depths of groundwater were greater than 5 m, restoration rate of species diversity reached at 46%, which means that the restorable rates of species diversity were high in the environments with high groundwater level and high soil moisture, where habitat heterogeneity showed by species turnover rates was high; so the high restorable rates of species diversity appeared at fluvial bog, non-sanded habitats and irrigated habitats. Overall, during the five years of ecological restoration, favorable or unfavorable human disturbance had influence on restoration of species diversity at some habitats but the magnitude of species turnover rate and restorable rate depended on degraded extent of environment and available extent of water.
出处
《干旱区地理》
CSCD
北大核心
2008年第6期870-877,共8页
Arid Land Geography
基金
国家自然科学基金(90502004,40671014)
国家973重点基础研究发展规划项目(2004CB720200/2004CB720201)资助
关键词
生态恢复
植物群落
物种替代速率
物种恢复速率
干旱内陆河
ecological restoration
plant communities
species turnover rates
species restorable rates
arid continental river
