A Study On The Eco-environmental Water Of The Primary Constructive Species By Populus Euphratica Oliver's Forests In Erjina County

Erjina oasis located in lower reaches of Heihe River was an important ecological screen of western regions of China and natural resources local people as well as garrison lived on, however this oasis was going to disappearance. This study made further analysis and research on the most critical factor–water among many ecological problems of this oasis.The average rainfall in Erjina region was less than 39mm, water resource was under extensive management and utilization for a long term. There were many problems in this region because of the sharp decrease of rainfall in upper and middle reaches of Heihe River, water resource was deficient, the construction of water conservancy was lag, the management of water resource was behindhand, and conflicts on water resource were ceaseless.To meet the ecological water consumption of local vegetation played a key role for ecological construction. This study made research and analysis on disciplinarians of water–consuming during transpiration of Populus euphratica Oliver, Elaegnus Angustifoia L, Tamrlx Chinensis Lour and Sophara alopecuroides L., constructed communities of local vegetation, and their relationships. The results showed that water consumption of Tamrlx Chinensis Lour, Elaegnus Angustifoial L and Sophara alopecuroides L. in whole year were 13.47mm, 4.59mm and 20.7mm respectively. The temperature of superficial leaves, relative humidity and stomatal resistance had conspicuous impacts on water-consuming during transpiration of plants.Populus euphratica Oliver was a kind of high water consumption plant, it was significant for ecological conservation and construction to make sure water consumption volume. This study confirmed water consumption volume at single wood and whole forest level by mensurating the liquid flow in tree trunk, results showed that Populus euphratica Oliver could keep in good condition when the water consumption volume of whole year was above 669.1mm.Underground water was the only valid water resource in providing ecological water consumption of plantations. This study about the relationship between vegetation growth and underground water indicated that the optimal underground water level was 2.88m, and the lowest level could not be less than 5m, water deficient coefficient kept above 0.5 for...