Effects of ecological water conveyance on groundwater dynamics and riparian vegetation in the lower reaches of Tarim River, China

On the basis of the field measurements of changes in groundwater level and plant species abundance along nine transects crossing the Tarim River in Xinjiang, China, we examined the responses of groundwater and plant communities to a government-controlled 7-year recharge regime to the lower reaches of the river. Our results showed that the water recharges considerably lifted the groundwater table on both sides of the river course. The 6-8-m groundwater depths before the water recharges rose to 2-4 m after the recharges. In the transverse direction, the response of the groundwater table could be observed at as far as 850 m from the river course, and the affected Populus euphratica could be observed at 700 m. However, we did not observe significant influence of the water recharges on herbaceous plants. We infer that the plant communities will be benefited more from the combination of overbank flows and stream aquifer recharge than from sole stream aquifer recharge. Such a combination may maximize the ecological benefits of water conveyance and accelerate the restoration of the damaged arid ecosystems in this area. Copyright (C) 2009 John Wiley & Sons, Ltd