The Study Of The Community‐structure Characteristics And Size Spectra Of Phytoplankton In Baishi Reservoir

To fully understand the structural characteristics of ecosystems of Baishi reservoir in Liaoning Province, reservoir water conservation sustainable fishery development direction, purification reservoir water quality objectives and provide a scientific basis and theoretical basis for ecological management of reservoir, this article started work on the establishment of a one-year Baishi Reservoir(August 2013 to July 2014) and the related investigation waters phytoplankton particle size spectrum.The investigation of water included relevant indicators of water quality and phytoplankton monitoring. Water quality monitoring indicators, including ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, reactive phosphorus, total nitrogen, total phosphorus, eight ions(calcium, magnesium, sodium, potassium, sulfate ion, carbonate ion, carbonate hydrogen ions, chloride ions), water temperature, p H, transparency, chlorophyll a and COD. Phytoplankton monitoring indicators, including species composition, density, biomass, dominant species, biodiversity and the particle size of phytoplankton cells. By the year access to the above index data, comparative analysis and particle size spectrum establish and perfect the mechanism of structural changes in phytoplankton community understanding, theory and application of particle size spectrum model ecological sustainable fisheries make better guidance.Survey showed that COD annual change in the range of 9.56~30.7 mg/L, the annual average of 16.9 mg/L; a sulfate annual change in the range of 23.1~84.2 mg/L, the annual average of 64.3 mg/L; P full activity changes in the range of 1.40×10-3~1.38×10-1 mg/L, the annual average of 3.30×10-2 mg/L; annual range nitrite nitrogen is 2.70×10-2~1.06×10-1 mg/L, annual average is 5.10×10-2 mg/L; range nitrate nitrogen in the year is 2.08~4.73 mg/L, annual average is 3.82 mg/L; range annual ammonia nitrogen is 1.00×10-4~1.99×10-2 mg/L, the annual average is 2.00×10-3 mg/L; annual total nitrogen ranged from 1.73×10-1~2.12 mg/L, annual average is 1.52 mg/L; annual total phosphorus ranged from 1.00×10-2~3.12×10-1 mg/L, annual average 5.60×10-2mg/L; annual chlorophyll a content ranged from4.00×10-3~5.30×10-2μg/L, annual average is 1.60×10-2μg/L; annual temperature range of 1.00~28.4℃, annual average of 14.0 ℃; p H value varied from 7.71~8.56, the annual average was 8.25.Survey results showed that 239 kinds of phytoplankton were found. It included 138 species of Chlorophyta, accounting for 57.74%; 39 species of Bacillariophyta, accounting for 16.32%; 26 species of Euglenophyta, accounting for 10.88%; 19 species of Cyanophyta, accounting for 7.95%; 8 species of Pyrrophyta, accounting for 3.35%; 3 species of Chrysophyta, Cryptophyta and Xanthophyta, accounting for 1.26%, respectively. The annual phytoplankton density ranged from 3.22×106~70.9×106 ind/L, The annual average of density of phytoplankton was 13.4×106ind/L; the annual biomass ranged from 3.45~34.8 mg/L, the annual average of biomass was 11.3mg/L.The dominant species were Phormidium tenue, Cryptomonas erosa, Synedra acus. Evenness index was 0.24~0.48, the average of the first anniversary of 0.36. Diversity index was 1.73~3.44, the average of the first anniversary of 2.61.Study on phytoplankton equivalent spherical diameter(ESD) annual distribution of 1.25~89.6μm range. The annual repertoire of biomass size spectra of Sheldon type’s of phytoplankton in four seasons, each with its own characteristics. It has the respective distribution of peaks and valleys in different size fractions. This may be related to the number of investigations related to seasonal changes in phytoplankton functional groups. Standardization biomass size spectra slope represents transmission efficiency of nutrient levels and environmental community energy, slope stability and natural ecosystems linear regression should be between-0.75 to-1. And in this study, the four seasons and annual standardized biomass size spectra of the slope(-0.74 to-1.07) floating slightly in its range, which may be related to seasonal variation of phytoplankton, but the difference was not significant.