黄河海勃湾水利枢纽对西鄂尔多斯国家级自然保护区胡杨岛的影响分析

海勃湾水利枢纽的建设、运行将对西鄂尔多斯胡杨岛旅游区产生不可逆的影响。经调查分析,胡杨岛胡杨种群分布面积为2.31 hm~2,总株数约为1 800株;胡杨种群表现出增长型特征;胡杨林总生物量为95.43 t。海勃湾水利工程运行后胡杨岛的淹没历时延长,淹没水深、淹没面积显著增加,岛北部低矮位置甚至全年淹没。胡杨部分种子可能落入水中被水流携带,丧失了种子繁殖的条件。根蘖产生的不定芽在4—6月生长期也会浸在水下,不能完成无性繁殖。胡杨幼苗树不高于2.5 m,淹没后无法生存。水库淹没将岛上以陆生生态为主的生态系统演变成以水生生态为主的生态系统,原有的旅游功能将发生变化或丧失,须采取生态补偿措施,减免工程造成的生态影响。

Study an impact from Haibowan Water Control Project of Yellow River on Populus Euphratica Island of West Erdos National Nature Reserve

The construction and operation of Haibowan Water Control Project has an irreversible impact on the Tourism Area of Populus Euphratica Island of the West Erdos. Through the relevant investigation，the species distribution area of Populus euphratica is 2.31 hm2 with the total plant-number of 1 800，while the population of Populus euphratica exhibits increasing characteristics with a total biomass of 95.43 t. The submerged period of the island is to be prolonged after the operation of Haibowan Water Control Project along with significant increases of the submerged depth and area，even the lower location of the north part of the island is to be submerged all year around. A part of the seeds are possibly to fall into water and be carried away by water flow，thus lose their propagation condition. Furthermore，the adventitious buds of the root sucker are to be also submerged in water during the growth period from April to June，and then are unable to finish their asexual propagation. Moreover，the saplings of Populus euphratica with the height lower than 2.5m cannot survive after inundation. The reservoir inundation makes the ecosystem of the island that mainly consists of terrestrial ecology-based ecosystem evolve into an ecosystem that mainly consists of aquatic ecology-based ecosystem，thus the original tourist functions are to be changed or lost，and then the relevant eco-compensation measures must be made，so as to reduce or remit the eco-impact caused by the project.