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| Effects of Nutrient Concentrations on Community Succession in Six Marine Microalga Species |
| LIANG Ying,LIU Chun-qiang,TIAN Chuan-yuan,SUN Ming-hui |
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Abstract In this paper ,six marine microalga species(Phaeodactylum tricornutum ,Nitzschiaclosterium f .minutissima , Dunaliella salina , Platymonas helgolandica var .tsingtaoensi , K arenia mikimotoi and Amphidinium carterae)were cultured together under different nutrient concentrations (2f medium ,f/2 medium ,and f/8 medium) ,different N concentrations (299 .2 mg/L ,74 .8 mg/L ,and 18 .7 mg/L) , different P concentrations (17 .6 mg/L ,4 .4 mg/L ,and 1 .1 mg/L ) and different Fe concentrations (15 .6 mg/L ,3 .9 mg/L ,and 0 .98 mg/L ) to evaluate the effects of nutrient concentrations on the community succession in the six species of microalgae .The results showed that green algae were the predominant in high nutrient concentration (2f medium) and accounted for 75 .6% of the total cell density .The diatoms had strong competitiveness with the decreasing nutrient concentrations ,accounting for 57 .0% of the total cell density in f/8 medium .The predominant diatoms were observed at high N concentration (299 .2 mg/L) ,representing 55 .7% of the total cell density .The competitiveness of diatoms was found to be declined with the decreasing N concentrations .In low N concentration (18 .7 mg/L) ,46 .6% of diatoms and 48 .3%of green algae were found and green algae were the predominant species in high P concentration (17 .6 mg/L) ,accounting for 63 .6% of the total cell density ,while the diatoms became dominant with the decline in P concentration ,accounting for 54 .3% of the total cell density in low P concentration (1 .1 mg/L ) . Diatoms had competitive advantage in high (15 .6 mg/L ) and low (0 .98 mg/L ) Fe concentrations , accounting for 71 .5% and 52 .1% of the total cell densities ,respectively .The dinoflagellates were inhibited in grow th with small proportion in the total cell densities in all treatments .
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Received: 25 November 2013
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