鄂尔多斯高原盐沼湿地浮游植物的多样性与评价

浮游植物是重要的湿地资源,其种类、数量、生长变化、种群结构与分布直接影响湿地生态系统的功能和效益。沙漠盐沼湿地生态系统中浮游植物多样性迄今未见报道。文中在2006、2007年每年的4-10月对鄂尔多斯高原盐沼湿地的桃-阿海子和红碱淖尔湖泊浮游植物多样性进行调查研究。调查方法依据《内陆水域渔业自然资源调查手册》进行,浮游植物多样性评价采用Pielou均匀度、Margalef丰度和Shannon-Weaver多样性指数计算。结果表明:2006、2007年红碱淖尔浮游植物分别为15种和18种,发现的藻类除半咸水或盐水种之外,大多数是淡水普生性的广盐种或喜盐种,由于碱度高,Ca2+含量极低,浮游植物的生物量不高,并且5.8g/L和6.2g/L的盐度恰好处于5~8g/L的水生生物耐盐性的极限范围内,生物种类较少。桃-阿海子两年分别发现4种、2种,主要是盐藻、螺旋藻等较典型的盐水种以及耐盐种和喜盐种。盐度不是决定浮游植物种类组成和分布的唯一生态因子;在所调查的湿地中,Na+摩尔百分数含量达43.3-48.1%,CO32-+HCO3-达12.7-26.3%,碳酸钠对硅藻具有毒性,随盐度升高毒性加剧,在桃-阿海子未检出硅藻,红碱淖尔也仅有三种;离子系数(M/D)是一项重要的生态指标,桃-阿海子浮游植物种类少于相似盐度的尕海内湖和夏日淖、桑根达莱淖,是因为湖水的离子系数太大。综合来看,浮游植物多样性受众多生态因子共同影响。

The diversity of phytoplankton in salina-alkaline wetland on the Erdos Plateau

Phytoplankton is one of the important wetland resources.The kinds,quantity,grouth diversification,distribution of phytoplankton affect the function and benefit of the wetland ecosystem directly.We haven't found any paper about phytoplankton diversity in desert salina wetland.We estimated the phytoplankton's diversity in Tao-A Haizi and Hongjian Nur of salina wetland on Erdos Plateau from Apr.to Oct.in 2006 and 2007.The surveying measures was according to the 《Investigation Handbook of Fisheries Natural Resources in Inland Waters》.The indexes of phytoplankton's diversity were reckoned by Margalef,Pielou,Shannon-Weaver indexes.Results showed: there were 15 species of phytoplankters in 2006 and it became 18 species in 2007 in Hongjian Nur lake.Most of them were fresh water kinds.Their biomass was little for there was high alkalinity and low Ca2+ in their living environment.The salinity was 5.8g/L and 6.2g/L.It was just with in the limit range of 5-8 g/l for the hydrobiont being able to bear the salt environment.There are little life-form kinds in this range.4 kinds phytoplankters became 2 from 2006 to 2007 in Tao-A Haizi lake.They were Dunaliella and Spiulina.They were typical salt genus.Salinity isn't the only factor to influence the kinds and distribution of phytoplankters.In the studying wetland,there was 43.3-48.1% of Na+ and 12.7-26.3% of CO2-3+HCO-3 mol percent.The sodium carbonate has poisons to the diatom.The poison is harder with the salinity higher.There was no diatom in TAO-A Haizi lake and only 3 kinds in Hongjian Nur lake.The ion quotiety(M/D) was a important condition.The phytoplankters in Tao-A Haizi lake were less than in Gahai salt lake,and Xiari Nur lake and Sanggengdalai Nur lake because of the high ion quotiety(M/D).