The Investigation And Analysis Of Advanced Aquatic Plant In Xiang Jiang

Advanced aquatic plants play an important role in water ecological system. It not only can absorb water sediments of nutrient and secrete his allelochemicals to suppress the phytoplankton growth, but also can improve the water ecological system of physical, chemical and biological characteristics. Xiang Jiang river is the largest river in Hunan province, is also one of the main tributaries of Yangtze river. Xiang Jiang River span 817 kilometers, cover 92,300 square kilometers. It originates from the northeast Guang Xi. It's upstream of water is from Guang Xi to Yong Zhou urban water rendezvous with Xiao. Continuing YongZhou flows eastwards, Heng Yang, Zhu Zhou and Xiang Tan, Chang Sha, Xiang Yin, Dongting lake as to the Yangtze river. Result in the rapid development of industry and the increase of population that large amounts of nutrients and pollutants continuously flows into the Xiang Jiang river, and make Aquatic plants face the fragmented habitats, species and migration of the block and the population close to critical ordeal. The ecological system of Aquatic plant material circulation plays an important role in regulation, and has a good effect and economic benefit. Barko J W thinks that submerged plant regeneration and repair is key to ecological restoration.In 2009, Advanced aquatic plants in Xiang Jiang river were investigated:1. Aquatic plants in Xiang Jiang river have 103 kinds,and belong to 17 families and 25 genera. The water level of Xiang Jiang river is great changes in upstream section. Both polymorphism and biomass Aquatic plants are rich.2. Level fluctuating zone that water height in Xiang Jiang midstream is relatively flat is broad, and main stream head drop is small, the water conservancy project of river wall leads to polymorphism singleness of emergent aquatic plant in level fluctuating zone, but biomass liveweight is abundant, and Arundo L. of gramineous is dominant species. Float plants in Bai Song town and Bai fang town relatively rich, summer eichhornia crassipe breeds excessivly, serious traffic trunk channel Xiang Jiang hindered. Bottom section due to mining, the serious destruction of aquatic plants environment can't cause the submerged plant a fixed.3. Level fluctuating zone that water height in Xiang Jiang downstream is relatively flat and broad, polymorphism abundant of emergent aquatic plant in level fluctuating zone.The polymorphism and biomass liveweight of aquatic plant is very abundant, which make good to water purification of Xiang Jiang.4. Invasive species Eichhornia crassipe and Alligator Alternanthera has broken the original ecological balance and formed superiority species.