Phytoplankton Functional Groups In The Artifical Lakes Formed From Land Subsidence In The Huainan Coal Mine Areas

The subsidence lakes occupies a central position in the ecological restoration in Huainan coal mine areas, the ecosystems structure and functional healthy is the prerequisite to guarantee the sustainable utilization of water resources in mine areas. Phytoplankton is the primary producers and food web of the starting point of lake water environment ecological system, is the foundation of regional fisheries function, but also the important indicator functional group of water ecological environment health. This paper aims to analyze the Huainan coal mine subsidence lakes phytoplankton community structure and functional group composition characteristics, and to reveal the relationship between the succession rules and aquatic ecosystems environmental factors, to provide basic data for the ecosystems structure and functional research, and provides theoretical guidance restoration for the ecological environment in mine areas.Select three small lakes at PXPJ site, PXGQ site and PXXQ site in Huainan Panxie coal mine subsidence area and the nearby city of Huainan HXH as research sites, These lakes water ecological environment in different conditions. The details are as follows:(1) To investigate the relation phytoplankton community with aquatic environmental factors in 2013-2014 four quarter for three lakes Panxie coal mine subsidence area and 2015-2016 12 months HXH. A total of 131 species of phytoplankton were identified, which belong to 7 phyla,70 genera in Panxie three small lakes. The primary phytoplankton species were Cyanophyta, Chlorophyta, and Bacillariophyta. Chlorophyta, Cyanophyta, and Bacillariophyta had 59,24 and 22 species, The predominant species density at PXPJ site are Chlorophyta, Bacillariophyta and Cryptophyta, The predominant species at PXGQ in summer and autumn is Cyanophyta, Cryptophyta is the major one at PXXQ site in spring, Cyanophyta and Chlorophyta is in summer and autumn. The abundance, diversity and uniformity of the three small subsided lakes could be influenced by the difference of eco-hydrological environment conditions. A total of 66 species of phytoplankton were identified, which belong to 6 phyla,43 genera in HXH lakes. The primary phytoplankton species were Cyanophyta, Chlorophyta, and Bacillariophyta. Chlorophyta, Cyanophyta, and Bacillariophyta had 38,13 and 7 species, The predominant species density at HXH site are Cryptophyta, Bacillariophyta and Cyanophyta, Due to changes in the environment, the abundance, diversity and uniformity of phytoplankton showed some fluctuations. Canonical correlation analysis (CCA) showed that light, temperature, nutrient content and ratios (TN/TP) were the keys factors affecting the different characteristics of phytoplankton community in subsided lakes.(2) According to the functional group(FGs) classification method proposed by Reynolds and Padisak, Panxie coal mine area three small identified 16 FGs. At the PXPJ site, FGs of S1, X2, and Y sites were predominant in spring, with Pseudanabaena sp., Chroomonas caudata Geitler, and Cryptomonas ovata Ehr. as representative species, respectively, whereas C(Cyclotella catenata as a representative) was the first predominant group in summer, autumn, and winter. At the PXGQ site, S1 with Pseudanabaena sp. as a representative was predominant in spring, summer, and autumn, which was then replaced by FGs of C(Cyclotella catenata as a representative) and D(Synedra acus Kiitzing as a representative). At the PXXQ site, FGs of X2 and Y were the predominant groups in spring, which were succeeded by S1 group in summer and autumn, and then replaced by C(Cyclotella catenata as a representative) and E (Dinobryon bavaricum Imhof as a representative) in winter.19 FGs were identified at HXH site in 2015, The main advantage FGs of the trend for the year is P(Jan.)â†'C, P, X1(Feb.)â†'X2, Y(Mar.-Jul.)-L0(Aug.)â†'L0, C(Sept.)â†'X2(Oct.)â†'X2, P(Nov.-Dec). 4 subsidence lakes functional groups are reflected lake eutrophication, high chlorophyll, water mixing characteristics, Canonical correlation analysis (CCA) showed that light and water temperature were the key factors affecting the phytoplankton functional groups succession rules in Huainan subsided lakes. The nutrients and biological factors are important reasons of four lakes functional group composition differences.(3) In the phosphate-free medium supplemented with 0-0.64 mg/L of phosphorus by gradient. At 25℃,4000 Lux to disposable cultivate phosphorus-starvation of Chroomonas caudata Geitler(1), Chlorella Beijierinck(2) and Pseudanabaena sp(3), Comparative study of three kinds of algaes exogenous phosphorus growth response at phosphorus-starvation, Using Monod equation calculated the maximum special growth rate (μmax) and semi-saturation constant(Ks), three kinds of algaes were 0.51 d-1,0.023 mg/L; 0.31 d-1,0.035 mg/L; 0.84 d-1,0.006 mg/L, Magnitude relationship were μmax3>μmax1>μmax2,sp3<Kspl<Ksp2, The results show whenever the phosphorus is scace or abundant, Pseudanabaena sp have stronger competition for resources, easier access to competitive advantage.(4) In the Nitrogen-free medium supplemented with 0-12.8 mg/L of nitrogen by gradient. At 25℃,4000 Lux to disposable cultivate nitrogen-starvation of Chroomonas caudata Geitler(1), Chlorella Beijierinck(2) and Pseudanabaena sp(3), Comparative study of three kinds of algaes exogenous nitrogen growth response at Nitrogen-starvation, Using Monod equation calculated the maximum special growth rate (μmax) and semi-saturation constant (Ks), three kinds of algaes were 0.66 d-1,1.66 mg/L; 0.37 d-1,1.06 mg/L; 0.71 d-1,2.26 mg/L, Magnitude relationship were μmax3>μmax1>μmax2,KSN3>KSN1>KSN2, Chlorella Beijierinck than Pseudanabaena sp and Chroomonas caudata Geitler have a stronger affinity for nitrogen, When the nitrogen is scarce, Chlorella Beijierinck have stronger competition for resources, easier access to competitive advantage. When the nitrogen is abundant, Pseudanabaena sp will be dominant.