三峡水库澎溪河回水区藻类种群分布及评价

【摘要】2008年冬,三峡水库蓄水至173m.随着蓄水水位的抬升,库区内长江干流北岸最大支流澎溪河回水区流速进一步减慢,水体富营养化发生的可能性相应增加.为探究水位抬升对澎溪河水环境及浮游植物种群结构产生的影响,本研究于2009年春季(3月)、夏季(7月)对该区域五个采样点展开浮游植物种群结构跟踪观测,并运用Margalef(d)丰富度指数法、Shannon-Wiener(H)多样性指数法、Pielou(J)均匀度指数法,进行水体富营养化评价.共检测出浮游植物7门57属100种,硅藻门17属33种、绿藻门24属40种、蓝藻门7属10种、甲藻门2属3种、裸藻门4属10种、黄藻门2属2种、隐藻门1属2种;硅藻和绿藻是该区域的优势种;其中春季藻类优势种群为硅藻-绿藻型,绝对优势种为硅藻;夏季藻类优势种群为绿藻-硅藻-蓝藻型,绝对优势种群为绿藻.高阳采样点春季发生铁锈红水华,藻类密度高达103.6×105cell/L.各监测断面的d、H、J值分别为:春季0.68~1.70、0.99~1.44、0.228~0.345,夏季1.0~1.91、1.24~2.10、0.30~0.49,综合得出澎溪河回水区春季属于中度-重度富营养化,夏季属于中度富营养化,夏季水质优于春季.

【英文摘要】

The water level of the Three GorgesReservoir (TGR)reached 173 min winter of 2008 .With the rise o f w ate r levelof the reservoir , the f lowing velocity of water slowed down and the possibility of eutrophication increased responding to the higher and larger backwaterarea of the Pengxi River , the largest tributary of TGR on its north shore .Tounderstand the effect of TGR on water quality and algal community in the PengxiRiver , water samples were collected at five sites along the river in spring(March)and summer (July)of 2009 , and phytoplankton community structure wasmonito red and evaluated with Margalef (d), Shannon-Wiener (H), and Pielou(J)metho ds .A total of 100 phytoplankton species belonging to 7 phyla and 57genera were detected , including 33 Bacilla riophyta species of 17 genera , 40Chlorophy taspecies of 24 genera , 10 Cyanophyta species of 7 genera , 3 Dinoflagellat species of 2 genera , 10 Euglenophyta species of 4 genera , 2 Xanthophy taspecies of 2 genera and 2 Cryptophy taspecies of 1 genus , indicating thatBacillariophy ta and Chlorophyta were the dominant populations in the region.In spring , phy toplankton was dominated by diatom algae-green algae , withinwhich diatom was more than the latter .In summer , phyto plankton showed typeof diatoms-blue-green algae , with more green algae .In spring of 2009 , rustred"spray"occurred at Gaoyang site in the slowest water velocity part ,and algal density was as high as 103.6 ×105 cell · L-1 .Thevalues of the monito ring sections calculated by d , H and J w ere 0.68 ～1.70 , 0.99 ～ 1.44 and0.228 ～ 0.345 in spring and 1.0 ～ 1.91 , 1.24 ～ 2.10 and0.30 ～ 0.49 in summe r ,respectively .In conclusion , water environment inbackwater area of the Pengxi River was in moderate-severe eutrophication inspring and in moderate degree o f eutrophication in summer , and water qualityin summer was better than in spring .